LITHOGEOCHEMISTRY OF VOLCANIC ROCKS … · Volcanogenic massive sulphide (VMS) deposits have ... 1)...

INTRODUCTION

Volcanogenic massive sulphide (VMS) deposits havebeen, and continue to be, important contributors to theCanadian and global economy. Many of these VMScamps have been significant producers for millennia(e.g. Iberian Pyrite Belt), and in many cases have con-tributed to the development of nations (e.g. Canadianand Australian VMS camps). Since the 1970s, litho-geochemistry has been an important tool in the explo-ration for VMS deposits with the majority of the earlystudies in the 1970s and 1980s focusing on alterationlithogeochemistry to outline alteration zones associ-ated with VMS mineralization (e.g. Ishikawa et al.,1976; Spitz and Darling, 1978; Date et al., 1983;Gibson et al., 1983; Campbell et al., 1984; Lesher etal., 1986a; Kranidiotis and MacLean, 1987; MacLeanand Kranidiotis, 1987; MacLean, 1988; Saeki andDate, 1980) and to discriminate prospective from lessprospective VMS belts (e.g. Lesher et al., 1986b;Paradis et al., 1988; Swinden et al., 1989). Fewer stud-ies have concentrated on sedimentary and exhalativerocks (e.g. Kalogeropoulos and Scott, 1983), mineralchemistry (e.g. Urabe and Scott, 1983; Urabe et al.,1983), and stable and radiogenic isotopes to assist inthe understanding of alteration systems and fluid- andmetal-source tracing (e.g. Kowalik et al., 1981;Spooner and Gale, 1982; Farrell and Holland, 1983;Fehn et al., 1983; Franklin et al., 1983; Green et al.,

1983; Watanabe and Sakai, 1983; Cumming and Krstic,1987; Schiffman and Smith, 1988).

The development of analytical technology has leadto major breakthroughs in lithogeochemistry since the1990s. One of the key advances has been the develop-ment of the inductively coupled plasma mass spec-trometer (ICP-MS) and more recently high-resolutionICP-MS (HR-ICP-MS). Once primarily a research toolin universities and government laboratories, the ICP-MS has become commonplace in most commercial labfacilities providing the ability to obtain high-qualityanalytical data for over forty trace elements with rapidturn-around times on a variety of matrices (e.g. rocks,soils, waters, and biological materials) (Jenner et al.,1990; Eggins et al., 1997; Sylvester, 2001; Günther andHattendorf, 2005, and references therein). The ICP-MShas revolutionized lithogeochemistry applied to VMSexploration and has led to major advancements in vol-canic lithogeochemistry (e.g. Swinden, 1991, 1996;Barrie et al., 1993b; Syme and Bailes, 1993; Barrettand Sherlock, 1996; Kerrich and Wyman, 1997; Lentz,1998; Syme, 1998; Syme et al., 1999; Wyman et al.,1999; Piercey et al., 2001a,b; Galley, 2003; Hart et al.,2004), alteration lithogeochemistry (e.g. Huston, 1993;Barrett and MacLean, 1994a,b, 1999; Large et al.,2001a,b), and sedimentary rock lithogeochemistry (e.g.Peter and Goodfellow, 1996; Davidson et al., 2001;Goodfellow et al., 2003; Peter, 2003). Furthermore, theICP-MS has allowed the utilization of a wider range of

LITHOGEOCHEMISTRY OF VOLCANIC ROCKS ASSOCIATED WITHVOLCANOGENIC MASSIVE SULPHIDE DEPOSITS AND

APPLICATIONS TO EXPLORATIONStephen J. Piercey

Stephen J. Piercey Geological Consulting, 11 First Avenue, St. John’s, Newfoundland A1B 1N3(also Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3X5)

ABSTRACT

Volcanic lithogeochemistry is a powerful tool in the exploration for volcanogenic massive sulphide(VMS) deposits. Primary lithogeochemical signatures associated with volcanic rocks (petrochemical signa-tures) provide critical information on the petrogenetic history and tectonic setting of volcanic rocks, whichin turn provide information on the thermal and geodynamic regime in which a belt has formed. Combinedwith stratigraphic context, the geochemistry of mafic and felsic rocks can be used to outline petrochemicalassemblages, which delineate potentially fertile from less fertile volcanic basins on a regional scale.

Once fertile areas are delineated, alteration lithogeochemistry can be utilized to elucidate the superim-posed effects of VMS-associated hydrothermal alteration. Recharge zones and semi-conformable alterationzones distal from mineralized zones (i.e. kms to 10s of kms) are characterized by patchy alteration and asso-ciated Mg-Na-Ca-Fe±(Si,CO2) enrichments and metal depletions. In contrast, areas proximal to upflow ordischarge zones (i.e. proximal or pipe-like alteration) are characterized by strong Na-Ca-depletions and vari-able enrichments in Fe, Mg, Si, K, metals±(CO2). The utilization of lithogeochemical data coupled withmass balance calculations, normative mineral plots, alteration indexes, and excellent geological and geo-

physical control can allow one to identify what part of the VMS alteration system one is in.

Piercey, S.J., 2009, Lithogeochemistry of volcanic rocks associated with volcanogenic massive sulphide deposits and applications to explo-ration, in Submarine Volcanism and Mineralization: Modern through Ancient, (eds.) B. Cousens and S.J. Piercey; Geological Association ofCanada, Short Course 29-30 May 2008, Quebec City, Canada, p. 15-40.

alteration/stringer zone

subvolcanic intrusion

lower semiconformablealteration zone

fracture/fault zones

FeZn

Cu Cu

Si

Mn,Ba

-Cu-Zn-Fe+Si+Ca+Na

-Si-Na-Ca

+Mg+K

+SO4

10s to100s ofmetres

100s ofmetres

hydrothermal plumes

500-2000 m

H2O/rock >>1

H2O/rock >1

15-30km

recharge zone

400ºC

300ºC

reservoir zone

spillitization

impermeable barrier

Mg-metasomatism

upper semiconformablealteration zone

+Si+Mg+CO2

mk3-1

silicification

H2O/rock <1

Figure 3-1. Model for the setting and genesis of volcanogenic massive sulphide (VMS) deposits (from Galley, 1993; Franklin et al., 2005; Galleyet al., 2007).

trace elements in lithogeochemical exploration, includ-ing the high field strength elements (HFSE) and rareearth elements (REE), elements that were unavailableto explorationists in the 1970s and 1980s, except atprohibitively high costs and with low turn-aroundtimes. Of particular importance has been the determi-nation of Th-Nb-Ta and the REE at ultra-low levels,particularly important for discriminating the tectonicenvironments of ancient VMS successions (e.g. Lesheret al., 1986b; Swinden, 1991; Barrie et al., 1993b;Lentz, 1998; Syme et al., 1999; Piercey et al., 2001b,2008; Piercey, 2007). Similarly, volatile metal species(e.g. Tl, Sb, As) and ultra-low level values for indica-tor elements (e.g. Mo, W) are also available now,whereas they were not as easily accessible prior to ICP-MS development.

The paper initially presents the nature of the VMStarget: the geological and tectonic setting, andhydrothermal alteration attributes of the VMS systemfrom the regional to local scale. The manuscript thenprovides an overview of the primary lithogeochemical

attributes of volcanic rocks associated with VMSdeposits, followed by an overview of lithogeochemicalattributes associated with the hydrothermal alterationof volcanic rocks associated with VMS systems. In thecase of the former, these attributes provide key infor-mation on the heat flow and tectonic environment ofVMS deposit formation, key features for area selection.The latter provide information on the nature of fluid-rock interaction and whether one is proximal to a min-eralized zone and what part of a VMS system one is in.The combination of both primary and secondary litho-geochemical signatures provides powerful tools in theexploration for VMS deposits.

THE TARGET: VOLCANOGENIC MASSIVE SULPHIDE DEPOSITS AND

THEIR CLASSIFICATION

The essential elements of the VMS system are pro-vided in Figure 3-1. Throughout Earth history, VMSdeposits formed, and continue to form, within exten-sional geodynamic regimes, in particular rift environ-

S. J. Piercey

16

ments. These rift environments include mid-oceanridges, back-arc basins, intraoceanic arc rifts, and con-tinental arc rifts (e.g. Swinden, 1991; Hannington etal., 1995, 2005; Scott, 1997; Syme et al., 1999; Barrettet al., 2001; Piercey et al., 2001b; Dusel-Bacon et al.,2004). On a belt scale, VMS deposits are associatedwith extensional grabens and calderas, synvolcanic andsynsedimentary faults, and significant variations in thethickness of sedimentary and volcanic units proximalto deposits (e.g. Gibson, 1989, 2005; Allen, 1992;McPhie and Allen, 1992; Setterfield et al., 1995; Allenet al., 1996; Gibson et al., 1999; Stix et al., 2003).Synvolcanic and synsedimentary structures are com-monly associated with felsic and mafic dyke swarmsthat parallel the axis of the rift corridor (e.g. Gibsonand Watkinson, 1990; Setterfield et al., 1995; Gibson etal., 1999) and are typically underlain by coeval synvol-canic intrusive complexes (e.g. Campbell et al., 1981;Galley, 1996, 2003). Dyke swarms and subvolcanicintrusive complexes commonly have geochemical sig-natures identical to the VMS-hosting volcanicsequences (e.g. Galley, 1996, 2003; Barrett andMacLean, 1999), and the subvolcanic intrusive com-plexes are interpreted to be the heat pump that drovehydrothermal circulation and potentially contributedmetals to the VMS hydrothermal system (e.g.Campbell et al., 1981; Galley, 1996, 2003; Large et al.,1996).

The generation of VMS deposits involves the draw-down of cold seawater on the flanks of the rift axis, thelateral transport of this fluid through the recharge zonewith progressive heating, the reduction of seawater sul-phate to sulphide by fluid-rock interaction and/or sul-phate loss owing to the retrograde solubility of anhy-drite, the stripping of metals and sulphur from the wallrocks, and the formation of semi-conformable alter-ation (e.g. Franklin et al., 1981, 2005; Gibson et al.,1983; Lydon, 1984; Large, 1992; Galley, 1993;Skirrow and Franklin, 1994; Ohmoto, 1996).Subsequent upwelling of fluids along synvolcanic andsynsedimentary structures through the discharge zoneresults in the deposition of massive sulphide on theseafloor or immediately beneath the rift, and below thesulphides there is the formation of a high-temperature,chlorite-(quartz)-rich alteration zone (Franklin et al.,1981, 2005; Lydon, 1984; Large, 1992; Galley, 1993;Ohmoto, 1996). In some VMS systems (e.g. Bathurst,Finlayson Lake, Iberian Pyrite Belt), the fluids ventinto anoxic basins with abundant organic- and sulfur-rich shale units, and these shale units record the anoxicnature of the ambient environment of deposition (e.g.Goodfellow and Peter, 1996; Goodfellow et al., 2003).In other VMS districts (e.g. Bathurst, Noranda, IberianPyrite Belt, Finlayson Lake, Windy Craggy), iron- andmetal-rich vent fluids exhaled onto the seafloor and

formed laterally extensive chemical sedimentary unitsand iron formations (e.g. Kalogeropoulos and Scott,1983; Duhig et al., 1992; Liaghat and MacLean, 1992;Peter and Goodfellow, 1996; Leistel et al., 1997; Spryet al., 2000; Davidson et al., 2001; Peter, 2003; Grenneand Slack, 2005).

There are significant differences in the style and set-ting of VMS deposits (e.g. Barrie and Hannington,1999; Franklin et al., 2005; Galley et al., 2007) and thishas a significant influence on the primary lithogeo-chemical signatures found in the VMS-associated vol-canic rocks. Consequently, a brief note on VMS classi-fication is warranted. Volcanogenic massive sulphidedeposits have been variously classified, but the mostrobust, from a regional perspective, are non-geneticand based on their host-rock assemblages (Barrie andHannington, 1999; Franklin et al., 2005; Galley et al.,2007). These authors have classified VMS depositsinto the following five groups.

1) Mafic: deposits associated with mafic-dominatedassemblages, commonly ophiolitic. The deposits ofCyprus, Oman, and ophiolite-hosted deposits in theNewfoundland Appalachians are representativedistricts/deposits of this group.

2) Bimodal-mafic: deposits associated with mafic-dominated settings, but with up to 25% felsicrocks; the latter commonly hosting the deposits.The deposits of the Noranda Camp, Flin Flon-Snow Lake, and Kidd Creek are representative dis-tricts/deposits of this group.

3) Siliciclastic-mafic (or pelitic-mafic): these aredeposits associated with subequal proportions ofmafic and siliciclastic rocks; felsic rocks can be aminor component; and mafic (and ultramafic)intrusive rocks are common. The deposits of theBesshi district in Japan and Windy Craggy, BritishColumbia are representative districts/deposits ofthis group.

4) Siliciclastic-felsic (or bimodal siliciclastic):deposits in siliciclastic-dominated settings withabundant felsic rocks and less than 10% maficmaterial. These settings are commonly shale-richand the Bathurst District, Iberian Pyrite Belt, andFinlayson Lake District are representative districtsof this group.

5) Bimodal-felsic: deposits associated with bimodalsequences where felsic rocks are in greater abun-dance than mafic rocks with only minor sedimen-tary rocks. The deposits of the Kuroko, Buchans,and Skellefte camps are representative districts ofthis group.

The first three VMS groups are dominated by maficmaterial and juvenile environments with very little

Lithogeochemistry of Volcanic Rocks Associated with VMS Deposits and Applications to Exploration

17

18

S. J. Piercey

continental crustal influence. Felsic rocks in these set-tings are derived primarily from melting of hydratedmafic crust, and mafic rocks are predominantlysourced from asthenospheric mantle. Deposits in thefirst three groups are enriched in Cu-Zn with very little

Pb. The last two groups are associated with evolvedenvironments dominated by continental crust or conti-nental crust-derived sedimentary rocks. Felsic rocks inthese environments are derived from melting of conti-nental crust or continental crust-derived rocks, andmafic rocks commonly are derived from mantlesources including both lithospheric and asthenosphericsources. The deposits of the last two groups are notablyZn-Pb-Cu dominated.

PRIMARY VOLCANIC LITHOGEOCHEMISTRY OF

VOLCANOGENIC MASSIVE SULPHIDE-ASSOCIATED ROCKS

The primary volcanic lithogeochemical signatures ofvolcanic suites provide significant insight into primarypetrological processes involved in generating a vol-canic assemblage. Understanding the primary petrolog-ical processes affecting a volcanic belt is critical in pro-viding information on the thermal, tectonic, and petro-logical history of a volcanic belt, key features that canbe used to delineate potentially fertile versus barrenvolcanic basins. When evaluating primary volcaniclithogeochemical signatures, it is critical that the fresh-est, least altered samples be taken. Namely, samplesshould have preserved textures, be free of veins andsecondary minerals, and have known stratigraphicposition. In addition, spatial control in the field and indrill core can provide insight into important primarylithogeochemical and petrological variations on aregional to local scale. In addition, in subaqueous andvariably altered volcanic sequences it is important torely on immobile major and trace elements, ones thatare not significantly mobilized during hydrothermalalteration and metamorphism, to understand primaryigneous processes, including Al2O3 and TiO2, the highfield strength elements (HFSE: Zr, Hf, Nb, Ta, Y, Sc,Ti, V), and rare earth elements (REE) (e.g. Jenner,1996; Kerrich and Wyman, 1997). Carbon dioxide-(CO2)-rich fluids, however, can mobilize the HFSEand REE (e.g. Murphy and Hynes, 1986) and thisshould be taken into consideration when dealing withstrongly carbonate-altered rocks.

Mafic Geochemistry

Mafic volcanism and plutonism associated with VMSdeposits is dependent on whether volcanism is associ-ated with juvenile or evolved substrates. In juvenileenvironments, deposits are preferentially associatedwith boninite and low-Ti tholeiite (LOTI) or mid-oceanridge basalt (MORB) of both the normal (N-MORB)and enriched (E-MORB) varieties (Figs. 3-2, 3-3, 3-4).Boninitic rocks are associated with many ophiolite-hosted (mafic) VMS deposits (e.g. Cyprus, Turner-Albright, Oman, Betts Cove) and bimodal mafic sys-

.1

1

10

100

1000

Th Nb La Ce Pr Nd Sm Zr Hf Eu Ti Gd Tb Dy Y Er Yb Lu Al V Sc

eltnaM eviti

mirP / kcoR

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

OIB (alkalic)

N-MORB

E-MORB

CAB

IAT / LOTI BON

.1

1

10

100

1000


elt naM e vit i

mirP / kc oR BABB

Alkalic

Figure 3-2. Primitive mantle normalized plots: (A) non-arc basalt;(B) arc basalt; and (C) transitional (back-arc and arc rift-relatedbasalt). Data from and Sun and McDonough (1989), Stoltz et al.(1990), Jenner (1981) Piercey et al. (2004), Ewart et al. (1994), andKepezhinskas et al. (1997). Abbreviations: BABB = back-arc basinbasalt; BON = boninite; CAB = calc-alkaline basalt; E-MORB(enriched mid-ocean ridge basalt); IAT = island arc tholeiite; LOTI =low-Ti island arc tholeiite; N-MORB = normal mid-ocean ridge basalt;and OIB = ocean island basalt. Primitive mantle values for this dia-gram and all others in this paper from Sun and McDonough (1989).

A

B

C

Figure 3-3. Primitive mantle normalized plots for mafic rocks asso-ciated with VMS deposits in mafic-dominated VMS environments,including (A) boninite; (B) low-Ti island arc tholeiite; (C) mid-oceanridge basalt (MORB) and back-arc basin basalt (BABB); and (D)ocean island basalt (OIB)-like. The low Eu values in the JosephineLOTI data are likely due to Eu loss during hydrothermal alteration.The high Nb values for West Shasta are likely erroneous. Datasources are listed in Appendix 3-1.

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

Boninites

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

Low Ti-Tholeiites (LOTI)

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

MORB and BABB

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

OIB-like

A B

C D

Snow Lake BON

Snow Lake LOTI

Flin Flon LOTI

Flin Flon MORB

Kamiskotia Contaminated MORB

Kidd Creek BON

Kutcho LOTI

Kutcho LREE-IAT

Kutcho MORB

Rambler BON

Rambler MORBNoranda Contaminated MORB

Noranda MORB

Tulsequah MORB #1

Tulsequah MORB #2

W. Shasta LOTI

W. Shasta MORB

Betts Cove BON

Betts Cove LOTI

Troodos BON

Troodos LOTI

Troodos LOTI

Josephine BON

Josephine LOTI

Josephine MORB/BABB

Fyre Lake BON

Windy Craggy E-MORB/OIB

cisleFcifaMssalC tisopeD SMV

-BROM ,etiieloht iT-wol ,etininoBcifaM

-)erar( etininob ,cilakla ,BROMcitsalciciliS cifaM

dnalsi dna cilakla-clac( etiieloht iT-wol ,etininob ,BROMcifaM ladomiB)rerar tub tneserp etiieloht cra

citiieloht- ciozorenahP-ciozoretorP .etiloyhr IIIF - naehcrAetiloyhr citininob ,etiloyhr

-clac dna enilaklarep ,)epyt-A( etiloyhr dehcirne-ESFHcilakla ,BROMcisleF ladomiB)rerar( etiloyhr cilakla

cilakla-clac dna ,enilaklarep ,etiloyhr dehcirne-ESFHcilakla ,BROMcitsalciciliS cisleF)rerar( etiloyhr

Table 3-1. Petrochemical assemblages of mafic and felsic rocks commonly associated with different VMS deposit classes (from Piercey, 2007).

19


tems (e.g. Kidd Creek, Snow Lake, Rambler), andmore rarely in mafic-siliciclastic systems (e.g. FyreLake) (Table 3-1). Boninitic-LOTI rocks are inter-preted to have formed from mantle sources that areultra-depleted in incompatible trace elements (i.e.ultra-depleted mantle) that require very high tempera-tures to melt (~1200-1500ºC) (Jenner, 1981; Crawfordet al., 1989; Pearce et al., 1992; van der Laan et al.,1992; Falloon and Danyushevsky, 2000). Furthermore,

most boninite is associated with fore-arc extensionassociated with the initiation of subduction (Brown andJenner, 1989; Stern and Bloomer, 1992; Kerrich et al.,1998; Bedard et al., 1999; Wyman et al., 1999) or withthe initiation of back-arc basin formation (Crawford etal., 1981; Piercey et al., 2001a).

Mid-ocean ridge basalts (MORB) are associatedwith many mafic-hosted VMS deposits in ophiolite,and modern mid-ocean ridges (e.g. TAG, East Pacific

Figure 3-4. Primitive mantle normalized plots for mafic rocks asso-ciated with volcanic massive sulphide deposits in modern oceans,including (A) back-arc basin basalt and island arc tholeiite, and (B) mid-ocean ridge basalt (MORB). The high Nb data for MiddleValley MORB are erroneous. Data sources are listed in Appendix 3-1.

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

Back-Arc Basin Basalts (BABB)and Island Arc Tholeiites (IAT)

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

Mid-Ocean Ridge Basalts (MORB)A B

Bransfield Strait IATBransfield Strait MORBOkinawa TroughContaminated MORBManus Basin BABBManus Basin MORB Axial Seamount MORB

East Pacific Rise MORBLau Basin IAT

Lau Basin MORBTAG MORBEscanaba Trough MORB

Guaymas MORBGuaymas BABB

Middle Valley MORB

ContinentalCrust-Associated Mafic-Associated

Figure 3-5. Primitive mantle normalized plots for mafic rocks asso-ciated with VMS deposits associated with continental crust including(A) mid-ocean ridge basalt (MORB) (note the enrichment in incom-patible elements, typical of enriched-MORB), and (B) alkalic, oceanisland basalt-like mafic rocks. Data sources are listed in Appendix 3-1.

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

Mid-Ocean Ridge Basalt (MORB (enriched))

.1

1

10

100

1000


eltnaM eviti

mirP / kcoR

Alkalic, Ocean Island Basalt (OIB)-LikeA B

Avoca MORBEskay Creek MORBKudz Ze Kayah OIBParys Mountain Contaminated MORBTulsequah MORBTulsequah BABBBathurst OIB

Delta/Bonnifield OIBIberian Pyrite BeltContaminated MORBIberian Pyrite Belt MORBIberian Pyrite Belt OIB

20

S. J. Piercey

Rise, Oman) and back-arc basins (e.g. Lau Basin)(Figs. 3-3, 3-4). MORB-like rocks with weak negativeNb anomalies on primitive mantle normalized plots,called back-arc basin basalts (BABB), are also presentin many mafic-type VMS environments in modern andancient back-arc basins (e.g., Lau Basin, Manus Basin,Semail). In mafic and bimodal-mafic systems (e.g.fore-arc or back-arc settings) the MORB-type rockscommonly show an intimate relationship with boniniticand arc-tholeiitic rocks, with MORB either underlying

boninite (e.g. Semail), or overlying and/or crosscuttingboninite (e.g. Troodos, Rambler, Turner-Albright)(Table 3-1). MORB-type rocks are also associated withmafic-siliciclastic deposits in both the ancient record(e.g. Windy Craggy, Greens Creek) and modern sedi-mented ridges (e.g. Middle Valley, Guaymas, andEscanaba Trough) (Table 3-1). MORB- and BABB-type rocks are interpreted to have formed from incom-patible element-depleted mantle with liquidus temper-atures of approximately 1200ºC (e.g. McKenzie and

21


Bickle, 1988; McKenzie and O’Nions, 1991; Langmuiret al., 1992) and represent extension either at mid-ocean ridges or within back-arc basins (e.g. Langmuiret al., 1992; Hawkins, 1995).

In evolved environments, deposits are preferentiallyassociated with mafic rocks that have MORB and alka-lic (or within-plate or ocean island basalt (OIB)) signa-tures (Figs. 3-2, 3-5). The MORB present in theevolved environments is commonly of E-MORB affin-ity and often there is a complete range of mafic rocksfrom incompatible element-depleted MORB, to weaklyincompatible element-enriched E-MORB, to incompat-ible element-enriched OIB (Fig. 3-5). The MORB-typeand OIB-like rocks often occur as sills and dykes thatcrosscut, or as flows that overlie felsic rocks and theassociated mineralization (i.e. they commonly post-date the main mineralization event). Furthermore, thereis commonly a stratigraphic progression upwards fromalkalic basalts to MORB (van Staal et al., 1991; Shinjoet al., 1999; Piercey et al., 2002a,b). Alkalic andMORB-type basalts are associated with many bimodal-felsic and felsic-siliciclastic settings from both themodern (e.g. Bransfield Strait, Okinawa Trough) andancient (e.g. Bathurst, Iberian Pyrite Belt, FinlaysonLake, Eskay Creek) geological record (Table 3-1), andare interpreted to represent melts derived from lithos-pheric (alkalic) to asthenospheric (MORB) mantlesources; the associated stratigraphic progression fromalkalic basalt to MORB is commonly interpreted toreflect a shift from rifting to true seafloor spreading(e.g. van Staal et al., 1991; Goodfellow et al., 1995;Barrett and Sherlock, 1996; Almodóvar et al., 1997;Shinjo et al., 1999; Colpron et al., 2002; Piercey et al.,2002a,b; Rogers and van Staal, 2003).

Felsic Geochemistry

Considerable research has been undertaken on the geo-chemistry of felsic rocks associated with VMS systems(e.g. Lesher et al., 1986b; Barrie et al., 1993a; Lentz,1998; Hart et al., 2004). Felsic rocks in VMS environ-ments that form via partial melting of, or interactionwith, continental crust are fundamentally different thanthose associated with partial melting of a mafic sub-strate, leading to different VMS-associated rhyolitesignatures dependent on the VMS environment (Table3-1). Furthermore, Archean felsic rocks have signa-tures and assemblages that are somewhat different thanpost-Archean VMS-associated felsic rocks.

In Archean terrains much of our knowledge on fel-sic volcanic geochemistry is from research in theSuperior Province of Canada (Lesher et al., 1986b;Barrie et al., 1993; Hart et al., 2004). Lesher et al.(1986b) outlined a tripartite subdivision of felsic rocksfor VMS-associated and barren rhyolites in theSuperior Province — the FI to FIII suites of rhyolite.

This classification was modified by Hart et al. (2004)to include a fourth suite, the FIV suite that is largelyrestricted to post-Archean juvenile terranes, andexpanded to a global database. The I suite of felsicrocks has low La/Ybn (and Zr/Y) ratios and high HFSEcontents (e.g. Zr>200 ppm) (Figs. 3-6, 3-7). The FI

Figure 3-6. La/Ybn-Ybn with FI-FIII-affinity rhyolite discriminationdiagrams (from Lesher et al., 1986b; Hart et al., 2004). (A) Archeanvolcanic massive sulphide-associated and barren felsic rocks. (B)Post-Archean volcanic massive sulphide-associated and barren rhy-olite from evolved environments. (C) Post-Archean volcanic massivesulphide-associated and barren rhyolite from juvenile environments.Data sources are listed in Appendix 3-1.

FI

FII

FIIIa FIIIb

FIV

0 40 80 120 160 200

1

10

100

1000

Ybn

bY/aLn

Panorama DacitePanorama Rhyolite(Barren)

Kidd Creek

Sturgeon Lake

Blake River (Noranda)

Blake River (Regional)

South Bay

Kamiskotia

High Lake

FI

FII

FIIIa FIIIb

FIV

0 40 80 120 160 200

1

10

100

1000

bY/aLn

Ybn

Finlayson Barren (calc-alkalic)

Finlayson Barren (tholeiitic)Finlayson Deposit-Hosting

Iberian Pyrite Belt

Bransfield Strait

Avoca

Okinawa Trough

Mount Read

Parys Mountain

Bathurst - Flat Landing Bk.

Bathurst - Nepisguit Falls

Eskay Creek

Delta-Bonnifield (Mystic Ck.)

A

B

FI

FII

FIIIaFIIIb

FIV

bY /aLn

Ybn0 40 80 120 160 200

1

10

100

1000Flin Flon (Calc-Alkalic - Barren)Flin Flon (Tholeiitic - Barren)Flin Flon (Mine Rhyolites)RamblerWest Shasta

Kutcho

Snow Lake (Primitive Arc)Snow Lake (Mature Arc)Snow Lake (Mature Arc- Powderhouse Dacite)

C

22

S. J. Piercey

suite has high La/Ybn ratios and lower HFSE contents(Figs. 3-6, 3-7). The FII suite has signatures intermedi-ate between the two groups (Figs. 3-6, 3-7). The major-ity of Archean VMS deposits are hosted by FIII and FIIfelsic rocks (Fig. 3-6), which are interpreted to haveformed within Archean rift sequences from high-tem-

perature melts (T>900ºC) derived from melting ofhydrated basaltic crust at shallow depths (Lesher et al.,1986b; Barrie et al., 1993; Barrie, 1995; Hart et al.,2004). The formation at shallow depths (i.e. <10 km)allowed these melts to rise to the surficial environmentwithout losing their heat of fusion (T>900ºC), thus,

0 10 20 30 40 500

100

200

300

400

500

600

700rZ

Nb

Zr > 200 ppm

Panorama Dacite(barren)Panorama Rhyolite

Kidd Creek

Sturgeon Lake

Blake River (Noranda)

Blake River (Regional)

South Bay

Kamiskotia

High Lake

A

Finlayson Barren (calc-alkalic)Finlayson Barren (tholeiitic)Finlayson Deposit-hostingIberian Pyrite BeltBransfield Strait

Avoca

Okinawa Trough

Mount ReadParys Mountain

Bathurst - Flat Landing Bk.

Bathurst - Nepisguit Falls

Eskay CreekDelta-Bonnifield (Mystic Ck.)

1 10 100 100010

100

1000

10000

rZ

Nb

Zr>200 ppm

Peralkaline

0 10 20 30 40 50 600

100

200

300

400

500

rZ

Nb

Zr>200 ppm

Flin Flon (Calc-Alkalic - Barren)Flin Flon (Tholeiitic - Barren)Flin Flon (Mine Rhyolites)RamblerWest Shasta

KutchoSnow Lake (Primitive Arc)Snow Lake (Mature Arc)Snow Lake (Mature Arc- Powderhouse Dacite)

B

C

Figure 3-7. Zr-Nb diagram illustrat-ing HFSE variations in rhyoliticrocks associated with volcanicmassive sulphide environments. (A) Archean volcanic massive sul-phide-associated and barren felsicrocks (South Bay Nb data are likelyerroneous). (B) Post-Archean vol-canic massive sulphide-associatedand barren rhyolite from evolvedenvironments. (C) Post-Archeanvolcanic massive sulphide-associ-ated and barren rhyolite from juve-nile environments. Data sourcesare listed in Appendix 3-1. Diagramafter Leat et al. (1986).

23


giving them greater ability to drive long-livedhydrothermal systems (e.g. Barrie et al., 1999). In con-trast, the other suites are interpreted to have formedfrom lower temperature melts (<900ºC) at deeper lev-els in the crust (>10 km) (Lesher et al., 1986b; Barrie,1995; Hart et al., 2004). These melts have less poten-tial to drive hydrothermal systems due to their lowertemperatures of fusion and loss of heat upon transportto the surface of the Earth from depth.

In Proterozoic and Phanerozoic terrains, the litho-geochemical signatures of felsic rocks are dependenton whether the felsic rocks are associated with juvenileor evolved environments. In post-Archean evolvedenvironments felsic rocks have a range of signatures,but most VMS deposits are associated with rhyolitethat has elevated HFSE and REE contents (Fig. 3-7)and FIII to FII signatures (Fig. 3-6); there is a tendencyfor rocks in these settings to have FII affinities, how-ever (Fig. 3-6) (Lentz, 1998; Hart et al., 2004; Pierceyet al., 2001b, 2008). Some rocks in these evolved set-tings, particularly those associated with continental riftor continental back-arc rifts (e.g. Delta-Bonnifield,Avoca), have rhyolite with extremely elevated HFSEcontent that is peralkalic in composition (e.g. Zr>500ppm; Fig. 3-7) (e.g. Mortensen and Godwin, 1982;McConnell, 1991; Dusel-Bacon et al., 2004). Like theirArchean equivalents, felsic rocks associated withevolved settings represent high-temperature (>900ºC)melting of crust within rift environments (e.g. conti-nental arc and back-arc rifts) (Lentz, 1998; Piercey etal., 2001b, in press).

In post-Archean juvenile environments, felsic rocksare unlike both Archean and evolved post-Archean set-tings. The rhyolite in juvenile environments typicallymirror the petrology of associated mafic rocks and havetholeiitic to boninitic affinities with low Zr/Y (<4) andLa/Ybn ration (Fig. 3-6), and depletions in HFSE andREE (e.g., Zr<50-100 ppm) (Fig. 3-7). In addition, therhyolite typically has flat REE profiles (not shown) andFIV affinities (Fig. 3-6). The rhyolite typically formsthe partial melting of mafic (to andesitic) substrates dur-ing fore-arc rifting, intra-arc rifting, or rifting during theinitiation of back-arc basin activity (e.g. Shukuno et al.2006). Their low overall trace element contents arelikely because of the low trace element compositions oftheir mafic source rocks (e.g. boninite and arc tholeiite).

ALTERATION LITHOGEOCHEMISTRY

Whereas petrochemistry provides indicators of the righttype of geodynamic environment, alteration lithogeo-chemistry provides insight into the existence of a poten-tial VMS hydrothermal system. Sampling to understandalteration is fundamentally different than petrochem-istry. In the latter we are interested in primary lithogeo-chemical attributes of rocks, whereas alteration litho-

geochemistry involves understanding the distributionof mobile elements. Sampling for alteration involves anumber of steps. The first step is to collect a suite ofrepresentative least altered samples. The samples couldbe the same samples used for petrochemistry and pro-vide the background to which all other samples arecompared. Altered samples then should be sampled as afunction of alteration mineralogy (quartz, chlorite,sericite, carbonate, etc.) and alteration intensity (e.g.strong, moderate, weak). If possible, end members ofalteration types should be chosen such that sampleswith mixed alteration assemblages can be compared. Inoutlining alteration zones, it is important to have spatialdistribution of samples. This can be achieved throughsampling traverses on properties or on a regional scale,or via detailed sampling in drill core. In both surfaceand drill core, sampling should be done at discreteintervals (e.g. every n boxes of drill core or every nkilometres in the field) where there are fundamentalchanges in lithology or where there are significantchanges in alteration type or intensity.

Alteration in VMS systems can be divided into twotypes: semiconformable alteration, and proximal orpipe-like alteration. These types of alteration arebroadly associated with zones of hydrothermalrecharge and discharge, respectively (e.g. Alt, 1995,1999). During hydrothermal recharge, lateral fluid flowresults in the formation of semiconformable alteration,generally at lower temperatures, and involves theleaching of metals from permeable zones within a foot-wall substrate (Galley, 1993, and references therein).Lateral fluid flow results in zoning of alteration miner-als, mineral chemistry, and lithogeochemistry in a ver-tical manner, due to the geothermal gradient, withaccompanying spillitization, silicification, epidote-quartz, and carbonization±potassic alteration(MacGeehan and MacLean, 1980; Munhá and Kerrich,1980; Munhá et al., 1980; Galley, 1993; Gibson et al.,1983; Morton et al., 1990; Skirrow and Franklin, 1994;Alt, 1995). The associated alteration products result invarying gains of Si, Ca, Fe, Na, Mg, CO2±K(MacGeehan and MacLean, 1980; Munhá and Kerrich,1980; Munhá et al., 1980; Morton et al., 1990; Galley,1993; Gibson et al., 1983; Skirrow and Franklin, 1994)and significant depletions in metals (Gibson et al.,1983; Richardson et al., 1987; Galley, 1993; Skirrowand Franklin, 1994; Alt, 1995, 1999). These semicon-formable alteration zones have significant lateral extent(e.g. 10s-100s of km; Galley, 1993) and alteration iscommonly patchy (rather than pervasive) in nature,with Mg-K enrichments in the uppermost parts of thecrust, and enrichments in Na-Mg, Na, and Ca-Fe withdepth (Galley, 1993).

Proximal, or pipe-like, alteration is discordant tostratigraphy and has a much smaller lateral extent (e.g.

S. J. Piercey

24

Northwest Formation

Lower Amulet Rhyolite

Upper contactofRusty Ridge Fm

Rusty Ridge FormationUpper contactofNorthwest Fm

Ansil QFP

FlavrianPluton

OutlineofAnsil Deposit

Flavrian Formation

0 400 m

2-3% Na2O

1-2% Na2O

0-1% Na2O

0 20 40 60 80 1000

2

4

6

8

10

12K

2O+N

a 2O

Igneous Spectrum(Weakly Altered)

Keratophyre(K-Metasomatism)

Spillite(Na Metasomatism)

100*K2O/Na2O+K2O

A

Fresh to WeaklyAlterated

Na Altered

Na Loss

0 1 2 3 4 5 6 70

10

20

30

40

50

Al 2O

3/N

a 2O

Qtz PorphyryRhyolite 1Rhyolite 1clastRhyolite 2

Rhyolite 3Lapillistone

Na2O

B

Figure 3-8. (A) Hughes (1973) diagram for outlining fresh, spillitized (Na-altered), and keratophyric (K-altered) igneous rocks. (B) Spitz-Darlingindex (Spitz and Darling, 1978) (Al2O3/Na2O) versus Na2O plot for outlining fresh rocks versus those with Na-gains (spillitized) and losses (dia-gram from Ruks et al., 2006). These diagrams are useful for delineating semiconformable alteration (spillitization, Na-gains) versus pipe-likealteration (Na-depletions). Data on the diagram are from Piercey (unpublished data).

A

0 1 km

D3Dacite

Zeolite

Montmorillonite

Chlorite-Sericite

Massive Sulphide

<0.4% Na2O

Fukazawa Mine

Figure 3-9. (A) Contoured Na2O contents for rhyolitic rocks of theBlake River Group, Quebec, Canada, associated with the Ansil VMSdeposit (from Galley, 1995; Galley et al., 1995), (B) and for daciticrocks at the Fuzakawa mine, Kuroko district, Japan (from Date et al.,1983). In both cases, the hydrothermal upflow zones are marked bystrong depletions in Na2O due to feldspar and glass destruction.These zones of Na-depletion are extremely simple, yet effective,exploration tools for volcanic massive sulphide exploration.

B


25

typically less than a few hundred metres). Proximalalteration zones represent hydrothermal upflow or dis-charge zones (e.g. feeder zones to the deposits) andform from high-temperature water-rock interaction.They have varying morphology but are typically pipe-like in impermeable strata (e.g. flows) and can haveirregular shapes in impermeable volcaniclastic or sedi-mentary strata (Riverin and Hodgson, 1980; Franklin etal., 1981, 2005; Gemmell and Large, 1992; Large,1992; Franklin, 1993, 1996; Gibson et al., 1999;Gemmell and Fulton, 2001; Large et al., 2001c;Gibson, 2005). These proximal alteration zones have awell developed zonation in alteration minerals andchemistry, from chlorite-(quartz)-rich cores to sericite-(quartz)-rich rims to quartz-sericite-rich envelopezones, reflecting increasing temperature of hydrother-mal fluid-rock interaction from rim to core of the alter-ation pipe (Riverin and Hodgson, 1980; Franklin et al.,1981, 2005; Knuckey et al., 1982; Richards et al.,1989; Gemmell and Large, 1992; Franklin, 1993, 1996;Gemmell and Fulton, 2001; Large et al., 2001a). Someproximal alteration zones are also associated with car-bonate (Lydon, 1984; Morton et al., 1990; Squires etal., 2001; Hudak et al., 2003; Bradshaw et al., 2008).Relative to background rocks, the alteration pipe ischaracterized by Ca-Na losses and Fe-Mg-K-Si-S-metal enrichments (e.g. Ishikawa et al., 1976; Spitz andDarling, 1978; Riverin and Hodgson, 1980; Date et al.,1983; Hashiguchi et al., 1983; Richards et al., 1989;Gemmell and Large, 1992; Galley et al., 1993; Huston,1993; Barrett and MacLean, 1994a,b; Lentz andGoodfellow, 1996; Gemmell and Fulton, 2001).

Various lithogeochemical tools can be used to iden-tify alteration zones. Utilization of major (and trace)element data can be useful in identifying alteration.

Spillitization versus K-metasomatism is importantfor delineating semiconformable versus pipe-like alter-ation, and can be done using the plot of Hughes (1973)(Fig. 3-8A). Spillitization versus Na-losses can also bedelineated using the Spitz-Darling index (Al2O3/Na2O)(Spitz and Darling, 1978) and Na2O contents (Fig. 3-8B). Similarly, contouring of raw alkali and metal val-ues can be useful in delineating potential alterationzones (Fig. 3-9). For example, simple contouring ofNa2O values by Date et al. (1983) and Galley et al.(1995) identified the proximal alteration zones beneaththe Kuroko and Ansil deposits, which are associatedwith marked Na-depletions (Fig. 3-9). Ternary plots ofmajor elements with various potential alteration miner-als have also proved useful for outlining different alter-ation types and pathways (Fig. 3-10) (Riverin andHodgson, 1980; MacDonald et al., 1996; Sebert et al.,2004), as have normative mineral plots (both CIPWand cation normative plots; Fig. 3-10) (e.g. Barrett and

muscovite

albite

epidote

biotite

phlogopite

etirolhc

MgO CaO+Na2O+K2O

Al2O3

actinolite

Least Altered Felsic

tremolite

Qtz PorphyryRhyolite 1

Rhyolite 1clast

Rhyolite 2

Rhyolite 3

Lapillistone

Sericite Chlorite

Quartz

Weakly altered

Moderately altered

Strongly altered

chlorititesericitite

precursor

gnihcael aciliS

0 10 20 30 40 5020

40

60

80

100

S

i cat

ion

%

(Fe+Mg) cation %

Weakly to moderatelyaltered rhyolite

precursor

etiloyhr deretla ylemertxE chloritesericite

quartz

Figure 3-10. Ternary plots of major elements and normative mineralcontents outlining volcanic massive sulphide-associated alteration.(A) MgO-Al2O3-(CaO+Na2O+K2O) plot (MacDonald et al., 1996;Sebert et al., 2004; data is from Piercey, unpublished data). (B) Cationnormative and (C) cation percentage plots illustrating various alter-ation minerals and alteration paths (from Barrett and MacLean,1991; MacLean and Barrett, 1993).

A

B

C

chloritepyritedolomite/ankerite

epidotecalcite

albiteDiagenetic Field

Alteration Field

Rhyolite

Dacite

Basaltand

Andesite

0 20 40 60 80 1000

20

40

60

80

100

CCPI

Hashimoto Index (AI)

xoB deretl

A tsaeL

AI = 100*(K2O+MgO)/(K2O+MgO+CaO+Na2O)CCPI = 100*(Fe2O3T+MgO)/( +Na2O)Fe2O3T+MgO+K2O

Qtz Porphyry

Rhyolite 1

Rhyolite 1clast

Rhyolite 2

Rhyolite 3

Lapillistone

sericite

K-feldspar

Figure 3-11. Alteration box plot with theHashimoto alteration index (AI) (Ishikawa et al.,1976) versus the chlorite-carbonate-pyrite index(CCPI) (CCPI and diagram from Large et al.,2001b). This diagram contains least altered fieldsfor various volcanic rocks and nodes for differentalteration minerals. Arrays on this diagram can beused to outline different alteration types, and dia-genetic (i.e. semiconformable) versus hydrother-mal (i.e. proximal or pipe-like) alteration. Data arefrom Piercey (unpublished data).

26

S. J. Piercey

MacLean, 1991; MacLean and Barrett, 1993; Liaghat andMacLean, 1995).

Most previous alteration diagrams are based on theloss of Ca-Na during the alteration process, followed bysubsequent gains in K (sericite), Fe-Mg (chlorite, car-bonate), and Si (quartz). This elemental behaviour is thepremise behind many alteration indexes, whereby ele-ments gained during the alteration process are normal-ized against elements lost during the process with theindex number increasing with greater intensity of alter-ation and proximity to mineralization (Ishikawa et al.,1976; Saeki and Date, 1980; Gemmell and Large, 1992;Gemmell and Fulton, 2001; Large et al., 2001b). Anovel approach to alteration indexes is the combinationof the Hashimoto alteration index (AI) and the chlorite-carbonate-pyrite index (CCPI) in the alteration box plotby Large et al. (2001b) (Fig. 3-11). This diagram con-tains a box for least altered samples and respectivenodes for alteration minerals (Fig. 3-11). Unalteredrocks lie within the least altered box, with varying alter-ation types forming trends towards the alteration nodes(Fig. 3-11).

Large et al. (2001a,c) recently illustrated that thevolatile elements Tl and Sb, once difficult to analyze,have very large dispersal halos (e.g. 100s of metres)around Zn-rich Australian VMS deposits (Fig. 3-12). Asimilar volatile element enrichment is observed in theDuck Pond and Boundary massive sulphide systems inthe Newfoundland Appalachians, where the alterationsystem is characterized by elevated Hg, Hg/Na2O, andBa/Sr ratios (Fig. 3-12) (Collins, 1989).

Previous methods involve data uncorrected for massvariations during alteration. More rigorous quantifica-

tion of mass variance and elemental gains and lossesduring alteration has been the focus of considerableresearch. Gresens (1967) provided one of the firstmethods to quantify mass and volume change duringalteration and metamorphism, and this method hasbeen utilized in VMS alteration studies by some work-ers (e.g. Gibson et al., 1983; Lesher et al., 1986a; Lentzand Goodfellow, 1993). Grant (1986) provided agraphical alternative to Gresens (1967), whereby theelemental concentrations in an altered rock are plottedagainst those in a fresh rock on an X-Y plot (Fig. 3-13)(see also Huston, 1993 and Baumgartner and Olsen,1995). Immobile elements in these diagrams form a lin-ear array (the isocon), the slope of which provides anindicator of the net mass gain or loss during alteration;elements that have been gained during the alterationprocess lie above the isocon and those that have beenlost during the alteration process lie below the isocon.MacLean and Barrett (MacLean, 1990; MacLean andBarrett, 1993; Barrett and MacLean, 1994a,b, 1999)devised a mass balance method that measured masschanges relative to igneous fractionation trends. Oncevarious igneous populations are identified, the alteredrocks are compared to the least altered rocks usingimmobile elements to obtain a mass-change factor (theenrichment factor). This factor is then utilized to masscorrect the altered samples, which are then compared tothe least altered suite to calculate elemental changes.This method provides a means of dealing with largedata sets quickly and provides an easy method for visu-alizing absolute mass changes (Fig. 3-13).

Stanley and Madeisky (1994) have utilized PearceElement Ratios (PER) to quantify metasomatism (seealso Robinson et al., 1996). PER diagrams are con-

.1 1 10 100 1000.1

1

10

100

1000Tl

Ore Proximal

BackgroundepolevnE erO

Qtz PorphyryRhyolite 1Rhyolite 1ClastRhyolite 2

Rhyolite 3

Lapillistone

Sb

100 m

200 m

100 m

Rosebery

Hellyer

Thalanga

Sb > 3 ppm Tl + Sb

Tl > 0.7 ppm massive ore

AB

Figure 3-12. ( A) Tl-Sb volatile element plot outlining the fields forbackground through to proximal alteration zones (from Large et al.,2001a). (B) Diagrams outlining the extent of volatile element halosaround some Australian volcanic massive sulphide deposits (fromLarge et al., 2001c). (C) Hg/Na2O-Ba/Sr plot of Collins (1989) fordelineating proximal versus barren alteration from the Tally Pond vol-canic belt, Newfoundland, Canada. Data in (A) and (B) are fromPiercey (unpublished data)..1 1 10 100 1000

.1

1

10

100

1000

Hg/

Na 2

O

Ba/Sr

Duck Pond and Boundary Horizons

Barren or

distal volcanic rocks

C

27


structed using molar ratios of potentially mobile ele-ments to a conserved denominator that is an immobileelement (e.g. Al or Zr); ratios are chosen to remove thepotential effects of closure and mass change on theabsolute concentrations of elements (Stanley andMadeisky, 1994). The diagrams have slopes that corre-spond to primary geological process (e.g. fractionalcrystallization) and secondary alteration minerals; sam-ples that deviate from the primary trend are affected byalteration (Fig. 3-13). The PER approach has not beenutilized extensively by workers in the VMS commu-nity; however, it has been applied very successfully ingold exploration (e.g. Eilu et al., 2001; Murphy andStanley, 2007; O’Connor-Parsons and Stanley, 2007),suggesting that it has considerable promise as an explo-ration tool in VMS systems.

DISCUSSION

Petrochemical Assemblages: A Regional Area Selection Tool

One of the key challenges in the exploration for VMSdeposits is the identification of fertile ground in green-fields areas. Primary lithogeochemical signatures ofmafic and felsic rocks have been utilized for identify-ing potentially prospective belts, as these signatures

provide key information on the tectonic setting andheat flow of a given volcanic assemblage. Most previ-ous studies on the primary lithogeochemistry of vol-canic rocks in VMS belts have either focused on felsic(e.g. Lesher et al., 1986b; Lentz, 1998; Hart et al.,2004) or mafic (e.g. Swinden et al., 1989; Swinden,1991) rocks, with less emphasis on the relationshipsbetween mafic and felsic rocks and associated sedimentary rocks or their chemostratigraphy.Petrochemical assemblages are an attempt to link thesedifferent data sets. Petrochemical assemblages arechemostratigraphic assemblages of mafic and felsicrocks that indicate a specific geodynamic environmentand are a predictive tool to identify environments withthe potential to host VMS mineralization (Fig. 3-c14;Table 3-1; Piercey, 2007).

In mafic-dominated VMS environments, boniniteand/or LOTI commonly host the VMS deposits but arecommonly overlain (or underlain) by MORB- orBABB-type rocks, indicative of fore-arc rifting or ini-tiation of back-arc spreading (Fig. 3-c14) (e.g.Swinden, 1991; Piercey et al., 1997; Bedard et al.,1999). In mafic-siliciclastic environments, the depositsare commonly associated with MORB (e.g. EscanabaTrough, Guaymas, Middle Valley), or more rarely OIB(e.g. Windy Craggy) or boninite (e.g. Fyre Lake),

20S30U

0.2Co

5Au

Fe3+

20Yb

100Lu

10Sm

30Eu0.1Cr

0.25Ba0.1Sr6Ca

0.5CeLa

20Ta10Th

100P 20Zr

Al

10C100Mn

20TiY

Si

Nb10Hf

Nd4Mg

0.1Ni10NaRb

Least altered basalt (average of 5)0 5 10 15 20 25 30 35 40 45 50

5

0

10

15

20

25

30

35

40

45

50

Sc 50Tb

100K

4-09U

CW tlasa

B dezitirolhC

Mass Gain

Mass Loss

ssaM tnatsnoC

-20 0 20-10

-8

-6

-4

-2

0

2

4

6

Δ(C

aO+N

a 2O

)

Δ(Fe2O3+MgO)

Flavrian andesiteNorthwest rhyoliteRhyolite dykes

plagioclasedestruction

chloritization involvingmass addtion of Fe+Mg

0.00 0.05 0.10 0.150.00

0.05

0.10

Mol

ar (N

a+K

)/Zr

Molar Al/Zr

)noitanoitcarf rapsdlef( 1 = m

)eticires( 3/1 = m

m - 0 (chlorite) (X-axis)

Qtz PorphyryRhyolite 1Rhyolite 1clastRhyolite 2Rhyolite 3Lapillistone

Figure 3-13. Various mass balance plots for VMS-associated alteration systems. (A) Isocon plot (Grant,1986) for altered basalt from the Windy Craggy deposit(Peter and Scott, 1999). (B) Δ(CaO+Na2O) versusΔ(Fe2O3+MgO) variations for volcanic rocks from theNoranda camp illustrating the absolute elementalgains and losses and the associated alteration paths(from MacLean and Barrett, 1993). (C) PearceElement Ratio (PER) diagram outlining various slopescorresponding to a primary igneous process (i.e.feldspar fractionation) and various alteration phases.Samples that lie off the primary trend are altered, andthe greater the deviation from the trend indicatesgreater alteration intensity (from Stanley andMadeisky, 1994).

A

CB

28

S. J. Piercey

indicative of formation within sedimented rifts or sed-imented back-arc rifts (Fig. 3-c14) (Saunders et al.,1982; Davis et al., 1994; Stakes and Franklin, 1994;Peter and Scott, 1999; Piercey et al., 2001a). Hot spotmagmatism may have been significant in the case ofthe OIB-type rocks at Windy Craggy (Peter and Scott,1999).

In bimodal-mafic environments, boninite and LOTIare commonly spatially associated with depleted boni-nite-like or tholeiitic rhyolite, with the rhyolite hostingmineralization (Fig. 3-c14) (e.g. Bailes and Galley,1999; Kerrich et al., 1998; Syme, 1998; Syme et al.,1999; Wyman et al., 1999; Bailey, 2002).Boninite/LOTI and associated rhyolite are commonlycrosscut and overlain by MORB-type basaltic rocks(Fig. C14) (Piercey et al., 1997; Bailes and Galley,1999; Syme et al., 1999; Wyman et al., 1999; Bailey,2002). In some bimodal mafic environments, thedeposits are hosted by FII-FIII rhyolite yet the under-lying mafic rocks are MORB in affinity (e.g. Noranda;Lafleche et al., 1992a,b; Hart et al., 2004). In all thesecases, the stratigraphic sequences are indicative of for-mation within rift environments, either via true spread-ing centres (e.g. Noranda) or via a transition from nor-mal arc volcanism to back-arc-related magmatic activ-

ity (e.g. Rambler, Flin Flon). In most cases, the felsicrocks that occur within these mafic-dominated envi-ronments mark the rift episode and reflect melting ofthe preexisting mafic-dominated substrate via mantleupwelling during the rift event (e.g. Meijer, 1983;Barrie et al., 1993; Prior et al., 1999).

In bimodal felsic and felsic-siliciclastic environ-ments, felsic rocks predominate over mafic rocks withfelsic rocks having calc-alkalic to within-plate (A-type)to peralkalic affinities (e.g. Lentz, 1999; McConnell etal., 1991; Piercey et al., 2001b; Dusel-Bacon et al.,2004). The felsic rocks are typically spatially associ-ated, crosscut, and overlain by OIB-like alkalic basaltand/or MORB-type basalt (e.g. van Staal et al., 1991;Barrett and Sherlock, 1996; Almodóvar et al., 1997;Piercey et al., 2002a,b; Rogers and van Staal, 2003). Insome cases, HFSE- and REE-enriched rhyolite isabsent and the rhyolite has normal, calc-alkalic affinity(i.e. Zr/Y>7 but with Zr<200 ppm and volcanic-arcaffinity on discrimination plots), but these rocks arecrosscut and/or overlain by OIB and/or MORB-typemafic rocks (Stolz, 1995; Dusel-Bacon et al., 2004).The occurrence of MORB and alkalic basalt in any fel-sic-dominated setting is indicative of rifting and the

29


upwelling of mantle beneath a continental crust-domi-nated substrate.

In all petrochemical assemblages, regardless ofdeposit type, there is the association of 1) rifting and 2)high-temperature magmatism. These two ingredientsare critical for the formation of a productive VMS envi-ronment. Rift environments are under extension formuch of their history resulting in extensional faultingand fracturing, providing the permeability necessaryfor focusing hydrothermal fluid flow, namely, provid-ing the conduits for fluid flow in the recharge zone andfaults for upwelling fluids in the discharge zone(Gibson and Watkinson, 1990; McPhie and Allen,1992; McPhie et al., 1993; Setterfield et al., 1995;Allen et al., 1996; Gibson et al., 1999, 2007; Gibson,2005; McCaig et al., 2007). In addition, rift environ-ments create void space at the base of the crust, whichallows for the upwelling of mantle, partial melting, thegeneration of basaltic magmas, ponding of this basalt atthe base of the crust, and, in many cases, eruption ofbasalt (e.g. McKenzie and Bickle, 1988; Hawkins,1995). The upwelling of mantle and ponding of basaltat the base of the crust leads to an elevated geothermalgradient in the rift environment (McKenzie and Bickle,1988; Hyndman et al., 2005; Currie and Hyndman,2006). This elevated gradient results in crustal partialmelting and the formation of the rhyolite that hostsmineralization in the bimodal VMS environments (e.g.Barrie et al., 1993; Lentz, 1998; Prior et al., 1999;Piercey et al., 2001b). Furthermore, the magmaticproducts from partial melting, including both the maficand felsic suites, typically have elevated temperatures(>~900ºC for felsic rocks and >~1200ºC for maficrocks), which are key in driving and maintaininghydrothermal circulation (Cathles, 1981, 1983; Barrieet al., 1999). The overall elevated geothermal gradientof the rift will also contribute to the maintenance ofhydrothermal circulation.

Alteration Lithogeochemistry: Identifying theVolcanogenic Massuve Sulphide Plumbing

System

Petrochemical assemblages provide the means of iden-tifying potentially prospective environments; however,they do not predict whether one is in a VMS hydrother-mal system or what part of a VMS system one might bein. Alteration lithogeochemistry, in contrast, can pro-vide critical information on the geochemical signaturesimposed on a volcanic unit by hydrothermal activity. Inusing alteration lithogeochemistry it is critical to iden-tify regional, semiconformable alteration within thehydrothermal recharge zone (i.e. distal to mineraliza-tion) versus proximal, pipe-like alteration representingthe discharge or upflow zones. Semiconformable alter-ation zones are notably patchy in their distribution but

are regionally extensive, often on the kilometres to tensof kilometres scale (MacGeehan and MacLean, 1980;Munhá et al., 1980; Munhá and Kerrich, 1980; Galley,1993; Gibson et al., 1983; Richardson et al., 1987; Alt,1995, 1999; Skirrow and Franklin, 1994). Regionalsemiconformable alteration zones are associated withsignificant gains in Na-Mg, losses in metals, silicifica-tion, and in some cases Ca-Fe enrichment (MacGeehanand MacLean, 1980; Munhá et al., 1980; Munhá andKerrich, 1980; Gibson et al., 1983; Richardson et al.,1987; Galley, 1993; Skirrow and Franklin, 1994; Alt,1995, 1999). Semiconformable alteration zones alsoexhibit 18O isotope enrichments (i.e. δ18O>6-8) due tolower temperature (<250ºC) water-rock interaction atrelatively low water-rock ratios (e.g. Munhá et al.,1980; Munhá and Kerrich, 1980; Schiffman and Smith,1988; Cathles, 1993; Paradis et al., 1993; Hanningtonet al., 2003b). Furthermore, semiconformable alter-ation zones are associated with Mg-rich chlorite, Fe-Mn-Mg-poor carbonate (e.g. calcite), high Fe/Al epi-dote, and Na-rich mica (e.g. Franklin et al., 1981; Gillisand Thompson, 1993; Saccocia and Seyfried, 1994;Saccocia et al., 1994; Alt, 1995; Santaguida, 2000;Large et al., 2001a; Hannington et al., 2003b).

Proximal alteration zones, in contrast, are associatedwith pervasive alteration that is at higher water-rockratios and generally at higher temperatures that areassociated with upwelling hydrothermal fluids(Franklin et al., 1981, 2005; Lydon, 1984; Gemmelland Large, 1992; Gemmell and Fulton, 2001). Thesezones are generally tens to hundreds of metres in scale,and are characterized by significant gains in Fe-Mg-K-Si, metals, S, in some cases CO2, and elevated Tl-Sb,along with high Ba/Sr, AI, CCPI, Hg/Na2O, andS/Na2O values (Figs. 3-9, 3-10, 3-12, 3-13, 3-c15) (e.g.Riverin and Hodgson, 1980; Saeki and Date, 1980;Date et al., 1983; Hashiguchi et al., 1983; Gemmell andLarge, 1992; Barrett and MacLean, 1994a,b, 1999;Galley et al., 1995; Gemmell and Fulton, 2001; Largeet al., 2001a). Proximal alteration zones are also asso-ciated with hydrothermal sedimentary rocks withchemical signatures indicating a dominantly hydrother-mal (versus detrital) origin (e.g. Kalogeropoulos andScott, 1983, 1989; Duhig et al., 1992; Liaghat andMacLean, 1992; Peter and Goodfellow, 1996, 2003;Davidson et al., 2001; Peter, 2003). Proximal alterationzones are associated with zones of 18O depletion(δ18O<6-8), indicative of high-temperature water-rockinteraction at high water-rock ratios (e.g. Green et al.,1983; Urabe and Scott, 1983; Taylor and South, 1985;Schiffman and Smith, 1988; Barrett and MacLean,1991; Cathles, 1993; Hoy et al., 1993; Paradis et al.,1993; Huston et al., 1995; Alt and Teagle, 1998;Huston and Taylor, 1999; Huston et al., 1999). Chloritefrom proximal zones is Fe-rich (i.e. high Fe/Mg ratio)

30

S. J. Piercey

in some cases (Franklin et al., 1981; Kranidiotis andMacLean, 1987; Zierenberg et al., 1988; Richards etal., 1989; Lentz and Goodfellow, 1993; Hannington etal., 2003b; Relvas et al., 2006), whereas in other it isMg-rich (Urabe and Scott, 1983; Urabe et al., 1983;Gemmell and Fulton, 2001; Large et al., 2001a) whenthe chlorite coprecipitates with pyrite or other Fe-bear-ing phases (Saccocia et al., 1994; Saccocia andSeyfried, 1994). Proximal epidotes have low Fe/Alratios (Gillis and Thompson, 1993; Santaguida, 2000;Hannington et al., 2003b), muscovite is typically K-and Ba-rich with low Na (Large et al., 2001a; Relvas etal., 2006; Bradshaw et al., 2008), and carbonate is typ-ically Fe- to Mn-rich (Large et al., 2001a; Hanningtonet al., 2003a; Bradshaw et al., 2008); some deposits areassociated with dolomite (Squires et al., 2001).

Combining petrochemistry and alteration lithogeo-chemistry provides a powerful tool for understandingthe VMS environment. Depending on the stage of theexploration program (e.g. greenfields area selectionversus brownfields near-mine exploration) differenttechniques will be utilized. In the early stages of explo-ration petrochemistry and reconnaissance alterationlithogeochemistry will be utilized more commonly,whereas in more advanced stages of exploration alter-ation lithogeochemistry and more refined alterationidentification methods (e.g. isotopes, mineral chem-istry) will be utilized.

SUMMARY

Volcanogenic massive sulphide (VMS) deposits remainattractive targets for exploration. While field-basedmethods and geophysics are critical tools in explo-ration for VMS deposit, lithogeochemistry has becomea common tool in exploration in both greenfields andbrownfields areas. In greenfields areas, prospectiveVMS belts are associated with petrochemical assem-blages that are indicative of rifting and high-tempera-ture magmatism. Rift zones and high-temperature mag-matism provide the crustal permeability required tofocus hydrothermal fluid recharge and discharge, andheat to drive hydrothermal circulation, respectively.Areas that exhibit these characteristics are prospectiveregions for further detailed, belt-scale exploration.

Belt-scale lithogeochemical tools are aimed prima-rily at identifying parts of the VMS hydrothermal sys-tem. The utilization of raw lithogeochemical data, nor-mative mineral plots, cation plots, alteration indexes,and various mass balance methods provide powerfultools in delineating regional, semiconformable(recharge-zone) alteration from proximal, pipe-like(discharge-zone) alteration. Petrochemical assem-blages and these various alteration lithogeochemicaltechniques, combined with geological mapping anddrill-core research documenting volcanic, sedimentary,

intrusive, and alteration facies, and other geophysical,mineralogical, and isotopic methods can lead to robustgenetic and exploration models for VMS systems.

ACKNOWLEDGEMENTS

I thank my colleagues whom I have had numerous dis-cussions with regarding lithogeochemistry and VMSdeposits: Jim Franklin, Alan Galley, Harold Gibson,Wayne Goodfellow, Mark Hannington, Tom Hart,Dave Lentz, Mike Lesher, Suzanne Paradis, and JanPeter. They have freely shared their ideas and thoughtsand have engaged in many fruitful discussions thathave focused my ideas and arguments. This paper waswritten while Steve Piercey was a sabbatical visitor inthe Department of Earth Sciences, MemorialUniversity of Newfoundland and Labrador (MUN).The faculty and staff at MUN are thanked for their hos-pitality and for numerous discussions, in particularDerek Wilton, John Hanchar, and Greg Dunning. StevePiercey’s research is funded by Discovery Grant fromthe Natural Sciences and Engineering ResearchCouncil (NSERC) of Canada. Thorough and thoughtfulreviews by Matt Leybourne and Brian Cousens aregreatly appreciated and have improved this manuscriptsignificantly.

REFERENCES

Allan, J.F., Batiza, R., and Lonsdale, P.F., 1987, Petrology andchemistry of lavas from seamounts flanking the EastPacific Rise axis, 21 degrees N; implications concerningthe mantle source composition for both seamount and adja-cent EPR lavas, in Seamounts, Islands, and Atolls, (eds.)B.H. Keating, P. Fryer, R. Batiza, and G.W. Boehlert;American Geophysical Union, Monograph 43, p. 255-282.

Allen, R.L., 1992, Reconstruction of the tectonic, volcanic, andsedimentary setting of strongly deformed Zn-Cu massivesulfide deposits at Benambra, Victoria; Economic Geology,v. 87, p. 825-854.

Allen, R.L., Lundstrom, I., Ripa, M., and Christofferson, H., 1996,Facies analysis of a 1 9 Ga, continental margin, back-arc,felsic caldera province with diverse Zn-Pb-Ag-(Cu-Au)sulfide and Fe oxide deposits, Bergslagen region, Sweden;Economic Geology, v. 91, p. 979-1008.

Almodóvar, G.R., Sáez, R., Pons, J.M., Maestre, A., Toscano, M.,and Pascual, E., 1997, Geology and genesis of theAznalcóllar massive sulfide deposits, Iberian Pyrite Belt,Spain; Mineralium Deposita, v. 33, p. 111-136.

Alt, J.C., 1995, Subseafloor processes in mid-ocean ridgehydrothermal systems, in Seafloor Hydrothermal Systems:Physical, Chemical, Biological, and GeologicalInteractions, (ed.) S.E. Humphris; American GeophysicalUnion, Monograph 91, p. 85-114.

Alt, J.C., 1999, Hydrothermal alteration and mineralization ofoceanic crust; mineralogy, geochemistry, and processes, inVolcanic-Associated Massive Sulfide Deposits: Processesand Examples in Modern and Ancient Environments, (eds.)C.T. Barrie, and M.D. Hannington; Society of EconomicGeologists, Reviews in Economic Geology, v. 8, p. 133-155.

Alt, J.C. and Teagle, D.A.H., 1998, Probing the TAG hydrothermalmound and stockwork; oxygen-isotopic profiles from deep

31


ocean drilling; Proceedings of the Ocean Drilling Program,Scientific Results, v. 158, p. 285-295.

Bailes, A.H. and Galley, A.G., 1999, Evolution of thePaleoproterozoic Snow Lake arc assemblage and geody-namic setting for associated volcanic-hosted massive sul-fide deposits, Flin Flon Belt, Manitoba, Canada; CanadianJournal of Earth Sciences, v. 36, p. 1789-1805.

Bailes, A.H. and Galley, A.G., 2001, Geochemistry and tectonic set-ting of volcanic and intrusive rocks in the VMS-hostingSnow Lake arc assemblage, Flin Flon Belt, Manitoba: Apreliminary release of the geochemical data set; ManitobaGeological Survey, Open File Report OF2001-6.

Bailey, J., 2002, Chemostratigraphy Surrounding the Ming MineVMS Mineralization in the Northern Pacquet HarbourGroup (PHG) and Correlations with the southern PHG, BaieVerte Peninsula, Newfoundland; B.Sc. thesis, MemorialUniversity of Newfoundland and Labrador, 125 p.

Barrett, T.J. and MacLean, W.H., 1991, Chemical, mass, and oxy-gen isotope changes during extreme hydrothermal alter-ation of an Archean rhyolite, Noranda, Quebec; EconomicGeology, v. 86, p. 406-414.

Barrett, T.J. and MacLean, W.H., 1994a, Chemostratigraphy andhydrothermal alteration in exploration for VHMS depositsin greenstones and younger rocks, in Alteration andAlteration Processes Associated with Ore-FormingSystems, (ed.) D.R. Lentz; Geological Association ofCanada, Short Course Notes Volume 11, p. 433-467.

Barrett, T.J. and MacLean, W.H., 1994b, Mass changes inhydrothermal alteration zones associated with VMSdeposits of the Noranda area; Exploration and MiningGeology, v. 3, p. 131-160.

Barrett, T.J. and MacLean, W.H., 1999, Volcanic sequences, litho-geochemistry, and hydrothermal alteration in some bimodalvolcanic-associated massive sulfide systems, in Volcanic-Associated Massive Sulfide Deposits: Processes andExamples in Modern and Ancient Environments, (eds.)C.T. Barrie and M.D. Hannington; Society of EconomicGeologists, Reviews in Economic Geology, v. 8, p. 101-131.

Barrett, T.J., MacLean, W.H., and Tennant, S.C., 2001, Volcanicsequence and alteration at the Parys Mountain volcanic-hosted massive sulfide deposit, Wales, United Kingdom:Applications of immobile element lithogeochemistry;Economic Geology, v. 96, p. 1279-1306.

Barrett, T.J. and Sherlock, R.L., 1996, Geology, lithogeochemistry,and volcanic setting of the Eskay Creek Au-Ag-Cu-Zndeposit, northwestern British Columbia; Exploration andMining Geology, v. 5, p. 339-368.

Barrett, T.J., Thompson, J.F.H., and Sherlock, R.L., 1996,Stratigraphic, lithogeochemical and tectonic setting of theKutcho Creek massive sulfide deposit, northern BritishColumbia; Exploration and Mining Geology, v. 5, p. 309-338.

Barrie, C.T., 1995, Zircon thermometry of high-temperature rhyo-lites near volcanic-associated massive sulfide deposits.Abitibi subprovince, Canada; Geology, v. 23, p. 169-172.

Barrie, C.T., Cathles, L.M., Erendi, A., Schwaiger, H., and Murray,C., 1999, Heat and fluid flow in volcanic-associated mas-sive sulfide-forming hydrothermal systems, in Volcanic-Associated Massive Sulfide Deposits: Processes andExamples in Modern and Ancient Environments, (eds.)C.T. Barrie and M.D. Hannington; Society of EconomicGeologists, Reviews in Economic Geology, v. 8, p. 201-219.

Barrie, C.T., and Hannington, M.D., 1999, Introduction:Classification of VMS deposits based on host rock compo-

sition, in Volcanic-Associated Massive Sulfide Deposits:Processes and Examples in Modern and AncientEnvironments, (eds.) C.T. Barrie and M.D. Hannington;Society of Economic Geologists, Reviews in EconomicGeology, v. 8, p. 2-10.

Barrie, C.T., Ludden, J.N., and Green, T.H., 1993, Geochemistry ofvolcanic rocks associated with Cu-Zn and Ni-Cu depositsin the Abitibi Subprovince; Economic Geology, v. 88, p.1341-1358.

Barrie, C.T. and Pattison, J., 1999, Fe-Ti basalts, high silica rhyo-lites, and the role of magmatic heat in the genesis of theKam-Kotia volcanic-associated massive sulfide deposit,western Abitibi Subprovince, Canada, in The Giant KiddCreek Volcanogenic Massive Sulfide Deposit, WesternAbitibi Subprovince, Canada, (eds.) M.D. Hannington andC.T. Barrie; Economic Geology, Monograph 10, p. 577-592.

Baumgartner, L.P. and Olsen, S.N., 1995, A least-squares approachto mass transport calculations using the isocon method;Economic Geology, v. 90, p. 1261-1270.

Bedard, J.H., 1999, Petrogenesis of boninite from the Betts CoveOphiolite, Newfoundland, Canada; identification of sub-ducted source components; Journal of Petrology, v. 40, p. 1853-1889.

Bedard, J.H., Lauziere, K., Tremblay, A., and Sangster, A., 1999,Evidence for forearc seafloor-spreading from the BettsCove Ophiolite, Newfoundland; oceanic crust of boniniticaffinity; Tectonophysics, v. 284, p. 223-245.

Bence, A.E. and Taylor, B.E., 1985, Rare earth elements systemat-ics of West Shasta metavolcanic rocks; petrogenesis andhydrothermal alteration; Economic Geology, v. 80, p. 2164-2176.

Bradshaw, G., Rowins, S.M., Peter, J.M., and Taylor, B.E., 2008,Genesis of the Wolverine volcanic sediment-hosted mas-sive sulfide deposit, Finlayson Lake District, Yukon,Canada: Mineralogical, mineral chemical, fluid inclusion,and sulfur isotope evidence; Economic Geology, v. 103, p. 35-60.

Brouxel, M., Lapierre, H., Michard, A., and Albarede, F., 1988,Geochemical study of an early Paleozoic island-arc-back-arc basin system; Part 2, Eastern Klamath, early to middlePaleozoic island-arc volcanic rocks (Northern California);with Suppl. Data 88-15; Geological Society of AmericaBulletin, v. 100, p. 1120-1130.

Brown, A. V. and Jenner, G.A., 1989, Geological setting, petrologyand chemistry of Cambrian boninite and low-Ti tholeiitelavas in western Tasmania, in Boninites and Related Rocks,(ed.) A.J. Crawford; Unwin Hyman : London, UnitedKingdom, p. 232.

Cameron, W.E., 1985, Petrology and origin of primitive lavas fromthe Troodos ophiolite, Cyprus; Contributions to Mineralogyand Petrology, v. 89, p. 239-255.

Campbell, I.H., Franklin, J.M., Gorton, M.P., Hart, T.R., and Scott,S.D., 1981, The role of subvolcanic sills in the generationof massive sulfide deposits; Economic Geology, v. 76, p. 2248-2253.

Campbell, I.H., Lesher, C.M., Coad, P., Franklin, J.M., Gorton,M.P., and Thurston, P.C., 1984, Rare-earth element mobil-ity in alteration pipes below massive Cu-Zn sulfidedeposits; Chemical Geology, v. 45, p. 181-202.

Cathles, L.M., 1981, Fluid flow and genesis of hydrothermal oredeposits, in Economic Geology Seventy-Fifth AnniversaryVolume, (ed.) B.J. Skinner; Society of EconomicGeologists, p. 1905-1980.

Cathles, L.M., 1983, An analysis of the hydrothermal systemresponsible for massive sulfide deposition in the Hokuroko

32

S. J. Piercey

basin of Japan, in The Kuroko and Related VolcanogenicMassive Sulfide Deposits, (eds.) H. Ohmoto and B.J.Skinner; Society of Economic Geologists, Monograph 5, p.439-487.

Cathles, L.M., 1993, Oxygen isotope alteration in the Noranda min-ing district, Abitibi greenstone belt, Quebec; EconomicGeology, v. 88, p. 1483-1511.

Collins, C.J., 1989, Report on lithogeochemical study of the TallyPond volcanics and associated alteration and mineraliza-tion; Unpublished Report for Noranda ExplorationCompany Limited (Assessment File 012A/1033Newfoundland Department of Mines and Energy, MineralLands Division), St. John’s, Newfoundland, 87 p.

Colpron, M., Logan, J.M., and Mortensen, J.K., 2002, U-Pb zirconage constraint for late Neoproterozoic rifting and initiationof the lower Paleozoic passive margin of western Laurentia;Canadian Journal of Earth Sciences, v. 39, p. 133-143.

Crawford, A.J., Beccaluva, L., and Serri, G., 1981, Tectono-mag-matic evolution of the West Philippine-Mariana region andthe origin of boninite; Earth and Planetary Science Letters,v. 54, p. 346.

Crawford, A.J., Corbett, K.D., and Everard, J.L., 1992,Geochemistry of the Cambrian volcanic-hosted massivesulfide-rich Mount Read volcanics, Tasmania, and sometectonic implications; Economic Geology, v. 87, p. 597-619.

Crawford, A.J., Falloon, T.J., and Green, D.H., 1989, Classification,petrogenesis, and tectonic setting of boninite, in Boninitesand Related Rocks, (ed.) A.J. Crawford; Unwin Hyman,London, p. 1-49.

Cumming, G.L. and Krstic, D., 1987, Detailed lead isotope study ofBuchans and related ores, in Buchans Geology,Newfoundland, (ed.) R.V. Kirkham; Geological Survey ofCanada, Paper 86-24, p. 227-233.

Currie, C.A. and Hyndman, R.D., 2006, The thermal structure ofsubduction zone back arcs; Journal of Geophysical Research,v. 111, B08404, 22 p., doi:10.1029/2005JB004024.

Date, J., Watanabe, Y., and Saeki, Y., 1983, Zonal alteration aroundthe Fukazawa Kuroko deposits, Akita Prefecture, northernJapan, in Kuroko and Related Volcanogenic MassiveSulfide Deposits, (eds.) H. Ohmoto and B.J. Skinner;Economic Geology, Monograph 5, p. 365-386.

Davidson, G.J., Stolz, A.J., and Eggins, S.M., 2001, Geochemicalanatomy of silica iron exhalites; evidence for hydrothermaloxyanion cycling in response to vent fluid redox and ther-mal evolution (Mt. Windsor Subprovince, Australia);Economic Geology, v. 96, p. 1201-1226.

Davis, A.S. and Clague, D.A., 1987, Geochemistry, mineralogy,and petrogenesis of basalt from the Gorda Ridge; Journal ofGeophysical Research, v. 92, p. 10,467-10,483.

Davis, A.S., Clague, D.A., and Friesen, W.B., 1994, Petrology andmineral chemistry of basalt from Escanaba Trough; UnitedStates Geological Survey, Bulletin B 2022, p.153-170.

Duhig, N.C., Stolz, J., Davidson, G.J., Large, R.R., and Large, R.R.,1992, Cambrian microbial and silica gel textures in silicairon exhalites from the Mount Windsor volcanic belt,Australia; their petrography, chemistry, and origin;Economic Geology, v. 87, p. 764-784.

Dusel-Bacon, C., Wooden, J.L., and Hopkins, M.J., 2004, U-Pb zir-con and geochemical evidence for bimodal mid-Paleozoicmagmatism and syngenetic base-metal mineralization inthe Yukon-Tanana Terrane, Alaska; Geological Society ofAmerica Bulletin, v. 116, p. 989-1015.

Eggins, S.M., Woodhead, J.D., Kinsley, L.P.J., Mortimer, G.E.,Sylvester, P., McCulloch, M.T., Hergt, J.M., and Handler,M.R., 1997, A simple method for the precise determinationof >40 trace elements in geological samples by ICP-MS

using enriched isotope internal standardisation; ChemicalGeology, v. 134, p. 311-326.

Eilu, P., Mikucki, E.J., and Dugdale, A.L., 2001, Alteration zoningand primary geochemical dispersion at the Bronzewinglode-gold deposit, Western Australia; Mineralium Deposita,v. 36, p. 13-31.

Ewart, A., Bryan, W.B., Chappell, B. W., and Rudnick, R.L., 1994,Regional geochemistry of the Lau-Tonga arc and backarcsystems; Proceedings of the Ocean Drilling Program,Scientific Results, v. 135, p. 385-425.

Falloon, T.J. and Danyushevsky, L.V., 2000, Melting of refractorymantle at 1·5, 2 and 2·5 GPa under anhydrous and H2O-undersaturated conditions: Implications for the petrogene-sis of high-Ca boninite and the influence of subductioncomponents on mantle melting; Journal of Petrology, v. 41,p. 257-283.

Farrell, C. W. and Holland, H.D., 1983, Strontium isotope geo-chemistry of the kuroko deposits, in The Kuroko andRelated Volcanogenic Massive Sulfide Deposits, (eds.) H.Ohmoto and B.J. Skinner; Economic Geology, Monograph5., p. 302-319.

Fehn, U., Doe, B.R., and Delevaux, M.H., 1983, The distribution oflead isotopes and the origin of kuroko ore deposits in theHokuroku District, Japan, in The Kuroko and RelatedVolcanogenic Massive Sulfide Deposits, (eds.) H. Ohmotoand B.J. Skinner; Economic Geology, Monograph 5, p. 488-506.

Franklin, J.M., 1993, Volcanic-associated massive sulfide deposits,in Mineral Deposit Modeling, (eds.) R.V. Kirkham, W.D.Sinclair, R.I. Thorpe, and J.M. Duke; GeologicalAssociation of Canada, Special Paper 40, p. 315-334.

Franklin, J.M., 1996, Volcanic-associated massive sulphide basemetals, in Geology of Canadian Mineral Deposit Types,(eds.) O.R. Eckstrand, W.D. Sinclair, and R.I. Thorpe;Geological Survey of Canada, Geology of Canada, no. 8, p.158-183.

Franklin, J.M., Lydon, J.W., and Sangster, D.F., 1981, Volcanic-associated massive sulfide deposits, in Economic Geology75th Anniversary Volume, (ed.) B.J. Skinner; p. 485-627.

Franklin, J.M., Sangster, D.F., Roscoe, S.M., and Loveridge, W.D.,1983, Lead Isotope Studies in Superior and SouthernProvinces; Geological Survey of Canada, Bulletin 351, 60 p.

Franklin, J.M., Gibson, H.L., Galley, A.G., and Jonasson, I.R.,2005, Volcanogenic massive sulfide deposits, in EconomicGeology 100th Anniversary Volume, (eds.) J.W.Hedenquist, J.F.H. Thompson, R.J. Goldfarb, and J.P.Richards; Society of Economic Geolgoists, p. 523-560.

Galley, A.G., 1993, Characteristics of semi-conformable alterationzones associated with volcanogenic massive sulfide dis-tricts; Journal of Geochemical Exploration, v. 48, p. 175-200.

Galley, A.G., 1995, Target vectoring using lithogeochemistry:Applications to exploration for volcanic-hosted massivesulfide deposits; Canadian Institute of Mining andMetallurgy Bulletin, v. 88, p. 15-27.

Galley, A.G., 1996, Geochemical characteristics of subvolcanicintrusions associated with Precambrian massive sulfidedeposits, in Trace Element Geochemistry of VolcanicRocks: Applications for Massive Sulfide Exploration, (ed.)D.A. Wyman; Geological Association of Canada, ShortCourse Notes, v. 12, p. 239-278.

Galley, A.G., 2003, Composite synvolcanic intrusions associatedwith Precambrian VMS-related hydrothermal systems;Mineralium Deposita, v. 38, p. 443-473.

Galley, A.G., Bailes, A.H., and Kitzler, G., 1993, Geological settingand hydrothermal evolution of the Chisel Lake and North

33


Chisel Zn-Pb-Cu-Ag-Au massive sulfide deposits, SnowLake, Manitoba; Exploration and Mining Geology, v. 2, p. 271-295.

Galley, A.G., Watkinson, D.H., Jonasson, I.R., and Riverin, G.,1995, The subsea-floor formation of volcanic-hosted mas-sive sulfide; evidence from the Ansil Deposit, Rouyn-Noranda, Canada; Economic Geology, v. 90, p. 2006-2017.

Galley, A.G., Hannington, M.D., and Jonasson, I., 2007,Volcanogenic massive sulphide deposits, in MineralDeposits of Canada: A Synthesis of Major Deposit Types,District Metallogeny, the Evolution of GeologicalProvinces, and Exploration Methods, (ed.) W.D.Goodfellow; Geological Association of Canada, MineralDeposits Division, Special Publication No. 5, p. 141-161.

Gemmell, J.B. and Fulton, R., 2001, Geology, genesis, and explo-ration implications of the footwall and hanging-wall alter-ation associated with the Hellyer volcanic-hosted massivesulfide deposit, Tasmania, Australia; Economic Geology, v. 96, p. 1003-1036.

Gemmell, J.B. and Large, R.R., 1992, Stringer system and alter-ation zones underlying the Hellyer volcanic-hosted massivesulfide deposit, Tasmania, Australia; Economic Geology, v. 87, p. 620-649.

Gibson, H.L., 1989, The Geology and Reconstruction of the MineSequence and the Noranda Cauldron of the NorandaComplex, northwestern Québec; Ph.D. thesis, CarltonUniversity, 715 p.

Gibson, H.L., 2005, Volcanic-hosted ore deposits, in Volcanoes inthe Environment, (eds.) J. Marti and G.G.J. Ernst;Cambridge University Press, New York, p. 332-386.

Gibson, H.L. and Watkinson, D.H., 1990, Volcanogenic massivesulfide deposits of the Noranda cauldron and shield vol-cano, Québec, in The Northwestern Québec PolymetallicBelt: A Summary of 60 Years of Mining Exploration,(eds.)M. Rive, P. Verpaelst, Y. Gagnon, J.-M. Lulin, G. Riverin,and A. Simard; Canadian Institute of Mining andMetallurgy, Special Volume 43, p. 119-132.

Gibson, H.L., Watkinson, D.H., and Comba, C. D.A., 1983,Silicification: Hydrothermal alteration in an Archean geot-hermal system within the Amulet Rhyolite Formation,Noranda, Quebec; Economic Geology, v. 78, p. 954-971.

Gibson, H.L., Morton, R.L., and Hudak, G.J., 1999, Submarine vol-canic processes, deposits, and environments favorable forthe location of volcanic-associated massive sulfidedeposits, in Volcanic-Associated Massive Sulfide Deposits:Processes and Examples in Modern and AncientEnvironments, (eds.) C.T. Barrie and M.D. Hannington;Society of Economic Geologists, Reviews in EconomicGeology, v. 8, p. 13-51.

Gibson, H.L., Allen, R.L., Riverin, G., and Lane, T.E., 2007, TheVMS model: Advances and application to exploration tar-geting, in Proceedings of Exploration 07: Fifth DecennialInternational Conference on Mineral Exploration; Toronto,ON, (ed.) B. Milkereit; p. 717-730.

Gillis, K.M. and Thompson, G., 1993, Metabasalts from the Mid-Atlantic Ridge: New insights into hydrothermal systems inslow-spreading crust; Contributions to Mineralogy andPetrology, v. 113, p. 503-523.

Goodfellow, W.D. and Peter, J.M., 1996, Sulfur isotope composi-tion of the Brunswick No. 12 massive sulfide deposit,Bathurst Mining Camp, New Brunswick: Implications forambient environment, sulfur source and ore genesis;Canadian Journal of Earth Sciences, v. 33, p. 231-251.

Goodfellow, W.D., Cecile, M.P., and Leybourne, M.I., 1995,Geochemistry, petrogenesis, and tectonic setting of lowerPaleozoic alkalic and potassic volcanic rocks, Northern

Canadian Cordillera Miogeocline; Canadian Journal ofEarth Sciences, v. 32, p. 1236-1254.

Goodfellow, W.D., Peter, J.M., Winchester, J.A., and van Staal,C.R., 2003, Ambient marine environment and sedimentprovenance during formation of massive sulfide deposits inthe Bathurst Mining Camp: Importance of reduced bottomwaters to sulfide precipitation and preservation, in MassiveSulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Main, (eds.) W.D. Goodfellow,S.R. McCutcheon, and J.M. Peter; Society of EconomicGeologists, Monograph 11, p. 129-156.

Grant, J.A., 1986, The isocon diagram: A simple solution toGresens’ equation for metasomatic alteration; EconomicGeology, v. 81, p. 1976-1982.

Green, G.R., Ohmoto, H., Date, J., and Takahashi, T., 1983, Whole-rock oxygen isotope distribution in the Fukazawa-Kosakaarea, Hokuroku District, Japan, and its potential applicationto mineral exploration, in The Kuroko and RelatedVolcanogenic Massive Sulfide Deposits, (eds.) H. Ohmotoand B.J. Skinner; Economic Geology, Monograph 5, p. 395-411.

Grenne, T. and Slack, J.F., 2005, Geochemistry of jasper beds fromthe Ordovician Lokken Ophiolite, Norway; origin of prox-imal and distal siliceous exhalites; Economic Geology, v. 100, p. 1511-1527.

Gresens, R.L., 1967, Composition-volume relationships of metaso-matism; Chemical Geology, v. 2, p. 47-65.

Günther, D. and Hattendorf, B., 2005, Laser Ablation-InductivelyCoupled Plasma Mass Spectrometry, in Encyclopedia ofMass Spectrometry, Volume 5: Elemental, Isotopic andInorganic Analysis by Mass Spectrometry, (eds.) M.L.Gross and R. Caprioli; Elsevier, Amsterdam, Netherlands.

Hannington, M.D., Jonasson, I.R., Herzig, P.M., and Petersen, S.,1995, Physical and chemical processes of seafloor mineral-ization at mid-ocean ridges, in Seafloor HydrothermalSystems: Physical, Chemical, Biological and GeologicalInteractions, (eds.) S.E. Humphris, R.A. Zierenberg, L.S.Mullineaux, and R.S. Thomson; American GeophysicalUnion, Monograph 91, p. 115-157.

Hannington, M.D., Kjarsgaard, I.M., Galley, A.G., and Taylor, B.,2003a, Mineral-chemical studies of metamorphosedhydrothermal alteration in the Kristineberg volcanogenicmassive sulfide district, Sweden; Mineralium Deposita, v. 38, p. 423-442.

Hannington, M.D., Santaguida, F., Kjarsgaard, I.M., and Cathles,L.M., 2003b, Regional-scale hydrothermal alteration in theCentral Blake River Group, western Abitibi subprovince,Canada: Implications for VMS prospectivity; MineraliumDeposita, v. 38, p. 393 - 422.

Hannington, M.D., de Ronde, C.E.J., and Petersen, S., 2005, Seafloor tectonics and submarine hydrothermal systems, inEconomic Geology One Hundredth Anniversary Volume,1905-2005, (eds.) J.W. Hedenquist, J.F.H. Thompson, R.J.Goldfarb, and J.P. Richards; Society of EconomicGeologists, p. 111-142.

Harper, G.D., 2003, Tectonic implications of boninite, arc tholeiite,and MORB magma types in the Josephine Ophiolite,California, Oregon, in Ophiolites in Earth History, (eds.) Y.Dilek and P.R. Robinson; Geological Society, SpecialPublications no. 218, p. 207-230.

Hart, T.R., 1984, The geochemistry and petrogenesis of a metavol-canic and intrusive sequence in the Kamiskotia area,Timmins, Ontario; M.Sc. thesis, University of Toronto,Toronto, Ontario.

Hart, T.R., Gibson, H.L., and Lesher, C.M., 2004, Trace elementgeochemistry and petrogenesis of felsic volcanic rocks

34

S. J. Piercey

associated with volcanogenic massive Cu-Zn-Pb sulfidedeposits; Economic Geology, v. 99, p. 1003-1013.

Hashiguchi, H., Yamada, R., and Inoue, T., 1983, Practical applica-tion of low Na2O anomalies in footwall acid lava for delim-iting promising areas around the Kosaka and FukazawaKuroko deposits, Akita Prefecture, Japan, in The Kurokoand Related Volcanogenic Massive Sulfide Deposits, (ed.)H. Ohmoto and B.J. Skinner; Economic Geology,Monograph 5, p. 387-394.

Hawkins, J. W., 1995, Evolution of the Lau Basin - Insights fromODP Leg 135, in Active Margins and Marginal Basins ofthe Western Pacific, (eds.) B. Taylor and J. Natland;American Geophysical Union, Monograph 88, p. 125-173.

Hocker, S.M., Thurston, P.C., and Gibson, H.L., 2005, VolcanicStratigraphy and Controls on Mineralization in the GenexMine Area, Kamiskotia Area; Discover Abitibi Initiative;Ontario Geological Survey, Open File Report 6156, 143 p.(+1 map).

Hoy, L.D., Spooner, E.T.C., and Barrie, C.T., 1993, Regional evo-lution of hydrothermal fluids in the Noranda District,Quebec; evidence from delta18 O values from vol-canogenic massive sulfide deposits; Economic Geology, v. 88, p. 1526-1541.

Hudak, G.J., Morton, R.L., Franklin, J.M., and Peterson, D.M.,2003, Morphology, distribution, and estimated eruptionvolumes for intracaldera tuffs associated with volcanic-hosted massive sulfide deposits in the Archean SturgeonLake Caldera Complex, northwestern Ontario; AmericanGeophysical Union, Geophysical Monograph 140, p. 345-360.

Hughes, C.J., 1973, Spilites, keratophyres, and the igneous spec-trum; Geological Magazine, v. 109, p. 513-527.

Huston, D.L., 1993, The effect of alteration and metamorphism onwall rocks to the Balcooma and Dry River South volcanic-hosted massive sulfide deposits, Queensland, Australia;Journal of Geochemical Exploration, v. 48, p. 277-307.

Huston, D.L., Barrie, C.T., and Hannington, M.D., 1999, Stable iso-topes and their significance for understanding the genesisof volcanic-hosted massive sulfide deposits; a review, inVolcanic-Associated Massive Sulfide Deposits: Processesand Examples in Modern and Ancient Environments, (eds.)C.T. Barrie and M.D. Hannington; Society of EconomicGeologists, Reviews in Economic Geology, v. 8, p. 157-179.

Huston, D.L. and Taylor, B.E., 1999, Genetic significance of oxy-gen and hydrogen isotope variations at the Kidd Creek vol-canic-hosted massive sulfide deposit, Ontario, Canada, inThe Giant Kidd Creek Volcanogenic Massive SulfideDeposit, Western Abitibi Subprovince, Canada, (eds.) M.D.Hannington and C.T. Barrie; Economic Geology,Monograph 10, p. 335-350.

Huston, D.L., Taylor, B.E., Bleeker, W., Stewart, B., Cook, R., andKoopman, E.R., 1995, Isotope mapping around the KiddCreek Deposit, Ontario; application to exploration andcomparison with other geochemical indicators; Explorationand Mining Geology, v. 4, p. 175-185.

Hyndman, R.D., Currie, C.A., and Mazzotti, S.P., 2005, Subductionzone backarcs, mobile belts, and orogenic heat; GSA Today,v. 15, p. 4-10.

Ishikawa, Y., Sawaguchi, T., Ywaya, S., and Horiuchi, M., 1976,Delineation of prospecting targets for Kuroko depositsbased on modes of volcanism of underlying dacite andalteration haloes; Mining Geology, v. 26, p. 105-117.

Jenner, G.A., 1981, Geochemistry of high-Mg andesites from CapeVogel, Papua New Guinea; Chemical Geology, v. 33, p. 307-322.

Jenner, G.A., 1996, Trace element geochemistry of igneous rocks:Geochemical nomenclature and analytical geochemistry, inTrace Element Geochemistry of Volcanic Rocks:Applications for Massive Sulfide Exploration, (ed.) D.A.Wyman; Geological Association of Canada, Short CourseNotes, v. 12, p. 51-77.

Jenner, G.A., Longerich, H.P., Jackson, S.E., and Fryer, B.J., 1990,ICP-MS - A powerful tool for high-precision trace elementanalysis in Earth sciences: Evidence from analysis ofselected U.S.G.S. reference samples; Chemical Geology, v. 83, p. 133-148.

Kalogeropoulos, S.I. and Scott, S.D., 1983, Mineralogy and geo-chemistry of tuffaceous exhalites (Tetsusekiei) of theFukazawa mine, Hokuroko District, Japan, in The Kurokoand Related Volcanogenic Massive Sulfide Deposits, (eds.)H. Ohmoto, and B.J. Skinner; Economic Geology,Monograph 5, p. 412-432.

Kalogeropoulos, S.I. and Scott, S.D., 1989, Mineralogy and geo-chemistry of an Archean tuffaceous exhalite; the MainContact Tuff, Millenbach Mine area, Noranda, Quebec;Canadian Journal of Earth Sciences, v. 26, p. 88-105.

Keller, R.A., Fisk, M.R., Smellie, J.L., Strelin, J.A., and Lawver,L.A., 2002, Geochemistry of back arc basin volcanism inBransfield Strait, Antarctica; subducted contributions andalong-axis variations; Journal of Geophysical Research, v. 107, 17 p., doi: 10.1029/2001JB000444.

Kepezhinskas, P., McDermott, F., Defant, M.J., Hochstaedter, A.,Drummond, M.S., Hawkesworth, C.J., Koloskov, A.,Maury, R.C., and Bellon, H., 1997, Trace element and Sr-Nb-Pb isotopic constraints on a three-component model ofKamchatka Arc petrogenesis; Geochimica etCosmochimica Acta, v. 61, p. 577-600.

Kerrich, R. and Wyman, D.A., 1997, Review of developments intrace-element fingerprinting of geodynamic settings andtheir implications for mineral exploration; AustralianJournal of Earth Sciences, v. 44, p. 465-487.

Kerrich, R., Wyman, D.A., Fan, J., and Bleeker, W., 1998, Boniniteseries; low Ti-tholeiite associations from the 2.7 Ga Abitibigreenstone belt; Earth and Planetary Science Letters, v. 164, p. 303-316.

Knuckey, M.J., Comba, C.D.A., and Riverin, G., 1982, Structure,metal zoning and alteration at the Millenbach Deposit,Noranda, Quebec, in Precambrian Sulphide Deposits, (eds.)R.W. Hutchinson, C.D. Spence, and J.M. Franklin;Geological Association of Canada, Special Paper 25, p. 255-295.

Kowalik, J., Rye, R.O., and Sawkins, F.J., 1981, Stable-isotopestudy of the Buchans, Newfoundland, polymetallic sulfidedeposits, in The Buchans Orebodies, Fifty Years ofGeology and Mining, (eds.) E.A. Swanson, D.F. Strong,and J.G. Thurlow; Geological Association of Canada,Special Paper 22, p. 229-254.

Kranidiotis, P. and MacLean, W.H., 1987, Systematics of chloritealteration at the Phelps Dodge massive sulfide deposit,Matagami, Quebec; Economic Geology, v. 82, p. 1898-1911.

Lafleche, M.R., Dupuy, C., and Bougault, H., 1992a, Geochemistryand petrogenesis of Archean mafic volcanic rocks of thesouthern Abitibi Belt, Quebec; Precambrian Research, v. 57, p. 3-4.

Lafleche, M.R., Dupuy, C., and Dostal, J., 1992b, Tholeiitic vol-canic rocks of the Late Archean Blake River Group, south-ern Abitibi greenstone belt: Origin and geodynamic impli-cations; Canadian Journal of Earth Sciences, v. 29, p. 1448-1458.

Langmuir, C.H., Klein, E.M., and Plank, T., 1992, Petrological sys-tematics of mid-ocean ridge basalts: Constraints on melt

35


generation beneath ocean ridges, in Mantle Flow and MeltGeneration at Mid-Ocean Ridges, (eds.) J.P. Morgan, D.K.Blackman, and J.M. Sinton; American Geophysical UnionMonograph, v. 71, p. 183-280.

Lapierre, H., Albarede, F., Albers, J., Cabanis, B., and Coulon, C.,1985, Early Devonian volcanism in the eastern KlamathMountains, California; evidence for an immature island arc;Canadian Journal of Earth Sciences, v. 22, p. 214-227.

Large, R.R., 1992, Australian volcanic-hosted massive sulfidedeposits; features, styles, and genetic models; EconomicGeology, v. 87, p. 471-510.

Large, R.R., Doyle, M., Raymond, O., Cooke, D., Jones, A., andHeasman, L., 1996, Evaluation of the role of Cambriangranites in the genesis of world class VHMS deposits inTasmania; Ore Geology Reviews, v. 10, p. 215-230.

Large, R.R., Allen, R.L., Blake, M.D., and Herrmann, W., 2001a,Hydrothermal alteration and volatile element haloes for theRosebery K Lens volcanic-hosted massive sulfide deposit,western Tasmania; Economic Geology, v. 96, p. 1055-1072.

Large, R.R., Gemmell, J.B., Paulick, H., and Huston, D.L., 2001b,The alteration box plot: A simple approach to understand-ing the relationships between alteration mineralogy andlithogeochemistry associated with VHMS deposits;Economic Geology, v. 96, p. 957-971.

Large, R.R., McPhie, J., Gemmell, J.B., Herrmann, W., andDavidson, G.J., 2001c, The spectrum of ore deposit types,volcanic environments, alteration halos, and related explo-ration vectors in submarine volcanic successions: Someexamples from Australia; Economic Geology, v. 96, p. 913-938.

Leat, P.T., Jackson, S.E., Thorpe, R.S., and Stillman, C.J., 1986,Geochemistry of bimodal basalt-subalkaline/peralkalinerhyolite provinces within the southern British Caledonides;Journal of the Geological Society, London, v. 143, p. 259-273.

Leistel, J.M., Marcoux, E., and Deschamps, Y., 1997, Chert in theIberian Pyrite Belt; Mineralium Deposita, v. 33, p. 59-81.

Lentz, D.R., 1998, Petrogenetic evolution of felsic volcanicsequences associated with Phanerozoic volcanic-hostedmassive sulfide systems: The role of extensional geody-namics; Ore Geology Reviews, v. 12, p. 289-327.

Lentz, D.R., 1999, Petrology, geochemistry and oxygen isotopicinterpretation of felsic volcanic and related rocks hostingthe Brunswick 6 and 12 massive sulfide deposits(Brunswick Belt), Bathurst Mining Camp, New Brunswick,Canada; Economic Geology, v. 94, p. 57-86.

Lentz, D.R., and Goodfellow, W.D., 1993, Petrology and mass-bal-ance constraints on the origin of quartz-augen schist asso-ciated with the Brunswick massive sulfide deposits,Bathurst, New Brunswick, Part 4; The CanadianMineralogist, v. 31, p. 877-903.

Lentz, D.R., and Goodfellow, W.D., 1996, Intense silicification offootwall sedimentary rocks in the stockwork alteration zonebeneath the Brunswick No. 12 massive sulfide deposit,Bathurst, New Brunswick; Canadian Journal of Earth, v. 33, p. 284-302.

Lesher, C.M., Gibson, H.L., and Campbell, I.H., 1986a,Composition-volume changes during hydrothermal alter-ation of andesite at Buttercup Hill, Noranda District,Quebec; Geochimica et Cosmochimica Acta, v. 50, p. 2693-2705.

Lesher, C.M., Goodwin, A.M., Campbell, I.H., and Gorton, M.P.,1986b, Trace element geochemistry of ore-associated andbarren felsic metavolcanic rocks in the Superior province,Canada; Canadian Journal of Earth Sciences, v. 23, p. 222-237.

Liaghat, S., and MacLean, W.H., 1992, The Key Tuffite, Matagamimining district; origin of the tuff components and masschanges; Exploration and Mining Geology, v. 1, p. 197-207.

Liaghat, S., and MacLean, H., 1995, Lithogeochemistry of alteredrocks at the New Insco VMS deposit, Noranda, Quebec;Journal of Geochemical Exploration, v. 52, p. 333-350.

Lydon, J. W., 1984, Volcanogenic sulphide deposits, Part 1, Adescriptive model; Geoscience Canada, v. 11, p. 195-202.

MacDonald, R. W.J., Barrett, T.J., and Sherlock, R.L., 1996,Geology and lithogeochemistry at the Hidden Creek mas-sive sulfide deposit, Anyonx, west-central BritishColumbia; Exploration and Mining Geology, v. 5, p. 369-398.

MacGeehan, P.J. and MacLean, W.H., 1980, An Archaean sub-seafloor geothermal system, `calc-alkaline‘ trends, andmassive sulfide genesis; Nature, v. 286, p. 767-771.

MacLean, W.H., 1988, Rare earth element mobility at constantinter-REE ratios in the alteration zone at the Phelps Dodgemassive sulfide deposit, Matagami, Quebec; MineraliumDeposita, v. 23, p. 231-238.

MacLean, W.H., 1990, Mass change calculations in altered rockseries; Mineralium Deposita, v. 25, p. 44-49.

MacLean, W.H. and Barrett, T.J., 1993, Lithogeochemical tech-niques using immobile elements; Journal of GeochemicalExploration, v. 48, p. 109-133.

MacLean, W.H. and Kranidiotis, P., 1987, Immobile elements asmonitors of mass transfer in hydrothermal alteration;Phelps Dodge massive sulfide deposit, Matagami, Quebec;Economic Geology, v. 82, p. 951-962.

McCaig, A.M., Cliff, R.A., Escartin, J., Fallick, A.E., andMacLeod, C.J., 2007, Oceanic detachment faults focus verylarge volumes of black smoker fluids; Geology, v. 35, p. 935-938.

McConnell, B., 1991, Geochemistry and mineralogy of volcanichost rocks as indicators of massive sulphide genesis atAvoca, Southeast Ireland; Irish Journal of Earth Sciences, v. 11, p. 43-52.

McConnell, B.J., Stillman, C.J., and Hertogen, J., 1991, AnOrdovician basalt to peralkaline rhyolite fractionationseries from Avoca, Ireland; Journal of the GeologicalSociety, London, v. 148, p. 711-718.

McKenzie, D., and Bickle, M.J., 1988, The volume and composi-tion of melt generated by extension of the lithosphere:Journal of Petrology, v. 29, p. 625-679.

McKenzie, D. and O’Nions, R.K., 1991, Partial melt distributionsfrom inversion of rare earth element concentrations;Journal of Petrology, v. 32, p. 1021-1091.

McPhie, J. and Allen, R.L., 1992, Facies architecture of mineralizedsubmarine volcanic sequences: Cambrian Mount Read vol-canics, western Tasmania; Economic Geology, v. 87, p. 587-596.

McPhie, J., Doyle, M., and Allen, R.L., 1993, Volcanic Textures: AGuide to the Interpretation of Textures in Volcanic Rocks;Centre for Ore Deposit and Exploration Studies, Universityof Tasmania, 198 p.

Meijer, A., 1983, The origin of low-K rhyolites from the Marianafrontal arc; Contributions to Mineralogy and Petrology, v. 83, p. 45-51.

Mitjavila, J.M., Marti, J., and Soriano, C., 1997, Magmatic evolu-tion and tectonic setting of the Iberian pyrite belt volcan-ism; Journal of Petrology, v. 38, p. 727-755.

Mortensen, J.K. and Godwin, C.I., 1982, Volcanogenic massive sul-fide deposits associated with highly alkaline rift volcanicsin the southeastern Yukon Territory; Economic Geology, v. 77, p. 1225-1230.

36

S. J. Piercey

Morton, R.L., Hudak, G.J., Walker, J.S., and Franklin, J.M., 1990,Physical volcanology and hydrothermal alteration of theSturgeon Lake caldera complex, in Mineral Deposits in theWestern Superior Province, Ontario, (eds.) J.M. Franklinand E.R. Koopman; Geological Survey of Canada, OpenFile 2164, p. 74-94.

Munhá, J. and Kerrich, R., 1980, Sea water-basalt interaction inspilites from the Iberian Pyrite Belt; Contributions toMineralogy and Petrology, v. 73, p. 191-200.

Munhá, J., Fyffe, W.S., and Kerrich, R., 1980, Adularia, the char-acteristic mineral of felsic spilites; Contributions toMineralogy and Petrology, v. 75, p. 15-19.

Murphy, D.M.K. and Stanley, C.R., 2007, Lithogeochemical con-straints on the host rock, hydrothermal alteration andweathering of the Groundrush gold deposit; Geochemistry:Exploration, Environment, Analysis, v. 7, p. 363-375.

Murphy, J.B. and Hynes, A.J., 1986, Contrasting secondary mobil-ity of Ti, P, Zr, Nb, and Y in two metabasaltic suites in theAppalachians; Canadian Journal of Earth Sciences, v. 23, p. 1138-1144.

O’Connor-Parsons, T. and Stanley, C.R., 2007, Downhole lithogeo-chemical patterns relating to chemostratigraphy andigneous fractionation processes in the Golden Mile dolerite,Western Australia; Geochemistry: Exploration,Environment, Analysis, v. 7, p. 109-127.

Ohmoto, H., 1996, Formation of volcanogenic massive sulfidedeposits: The Kuroko perspective; Ore Geology Reviews,v. 10, p. 135-177.

Paradis, S., Ludden, J.N., and Gelinas, L., 1988, Evidence for con-trasting compositional spectra in comagmatic intrusive andextrusive rocks of the late Archean Blake River Group,Abitibi, Quebec; Canadian Journal of Earth Sciences, v. 25,p. 134-144.

Paradis, S., Taylor, B.E., Watkinson, D.H., and Jonasson, I.J., 1993,Oxygen isotope zonation and alteration in the Norandamining district, Abitibi greenstone belt, Quebec; EconomicGeology, v. 88, p. 1512-1525.

Pearce, J.A., van der Laan, S.R., Arculus, R.J., Murton, B.J., Ishii,T., Peate, D. W., and Parkinson, I.J., 1992, Boninite andharzburgite from Leg 125 (Bonin-Mariana forearc); a casestudy of magma genesis during the initial stages of subduc-tion; Proceedings of the Ocean Drilling Program, ScientificResults, v. 125, p. 623-659.

Péloquin, A.S., 1999, Reappraisal of the Blake River GroupStratigraphy and Its Place in the Archean Volcanic Record;Ph.D. thesis, Université de Montréal, Montreal, Quebec,189 p.

Petch, C.A., 2004, The geology and mineralization of the HighLake volcanic-hosted massive sulfide deposit, Nunavut;Exploration and Mining Geology, v. 13, p. 37-47.

Peter, J.M., 2003, Ancient iron formations: Their genesis and use inthe exploration for stratiform base metal sulfide deposits,with examples from the Bathurst Mining Camp, inGeochemistry of Sediments and Sedimentary Rocks:Secular Evolutionary Considerations to Mineral Deposit-Forming Environments, (ed.) D.R. Lentz; GeologicalAssociation of Canada, GEOtext, v.4., p. 145-176.

Peter, J.M. and Goodfellow, W.D., 1996, Mineralogy, bulk and rareearth element geochemistry of massive sulphide-associatedhydrothermal sediments of the Brunswick horizon,Bathurst mining camp, New Brunswick; Canadian Journalof Earth Sciences, v. 33, p. 252-283.

Peter, J.M. and Goodfellow, W.D., 2003, Hydrothermal sedimen-tary rocks of the Heath Steele Belt, Bathurst mining camp,New Brunswick; Part 3, Application of mineralogy andmineral and bulk compositions to massive sulfide explo-

ration, in Massive Sulfide Deposits of the Bathurst MiningCamp, New Brunswick, and Northern Main, (eds.) W.D.Goodfellow, S.R. McCutcheon, and J.M. Peter; Society ofEconomic Geologists, Monograph 11, p. 417-433.

Peter, J.M., and Scott, S.D., 1999, Windy Craggy, northwesternBritish Columbia; the world’s largest besshi-type deposit,in Volcanic-Associated Massive Sulfide Deposits:Processes and Examples in Modern and AncientEnvironments, (eds.) C.T. Barrie and M.D. Hannington;Society of Economic Geologists, Reviews in EconomicGeology, v. 8, p. 261-295.

Petersen, S., Herzig, P.M., Schwarz-Schampera, U., Hannington,M.D., and Jonasson, I.R., 2004, Hydrothermal precipitatesassociated with bimodal volcanism in the central BransfieldStrait, Antarctica; Mineralium Deposita, v. 39, p. 358-379.

Piercey, S.J., 2007, An overview of the use of petrochemistry in theregional exploration for volcanogenic massive sulfide(VMS) deposits, in Proceedings of Exploration 07, (ed.) B.Milkereit; Fifth Decennial International Conference onMineral Exploration, Toronto, ON, p. 223-246.

Piercey, S.J., Jenner, G.A., and Wilton, D.H.C., 1997, The stratigra-phy and geochemistry of the southern Pacquet HarbourGroup, Baie Verte Peninsula, Newfoundland; implicationsfor mineral exploration, in Current Research, (eds.) C.P.G.Pereira and D.G. Walsh; Newfoundland and LabradorDepartment of Mines and Energy, p. 119-139.

Piercey, S.J., Murphy, D.C., Mortensen, J.K., and Paradis, S.,2001a, Boninitic magmatism in a continental margin set-ting, Yukon-Tanana Terrane, southeastern Yukon, Canada;Geology, v. 29, p. 731-734.

Piercey, S.J., Paradis, S., Murphy, D.C., and Mortensen, J.K.,2001b, Geochemistry and paleotectonic setting of felsicvolcanic rocks in the Finlayson Lake volcanic-hosted mas-sive sulfide (VHMS) district, Yukon, Canada; EconomicGeology, v. 96, p. 1877-1905.

Piercey, S.J., Murphy, D.C., Mortensen, J.K., Paradis, S., andCreaser, R.A., 2002a, Geochemistry and tectonic signifi-cance of alkalic mafic magmatism in the Yukon-TananaTerrane, Finlayson Lake Region, Yukon; Canadian Journalof Earth Sciences, v. 39, p. 1729-1744.

Piercey, S.J., Paradis, S., Peter, J.M., and Tucker, T.L., 2002b,Geochemistry of basalt from the Wolverine volcanic-hostedmassive-sulfide deposit, Finlayson Lake district, YukonTerritory; Geological Survey of Canada, Current Research2002-A3, 11 p.

Piercey, S.J., Murphy, D.C., Mortensen, J.K., and Creaser, R.A.,2004, Mid-Paleozoic initiation of the northern Cordilleranmarginal back-arc basin: Geological, geochemical andneodymium isotopic evidence from the oldest mafic mag-matic rocks in Yukon-Tanana terrane, Finlayson Lake dis-trict, southeast Yukon, Canada; Geological Society ofAmerica Bulletin, v. 116, p. 1087-1106.

Piercey, S.J., Peter, J.M., Mortensen, J.K., Paradis, S., Murphy,D.C., and Tucker, T.L., 2008, Petrology and U-Pbgeochronology of footwall porphyritic rhyolites from theWolverine volcanogenic massive sulfide deposit, Yukon,Canada: Implications for the genesis of massive sulfidedeposits in continental margin environments; EconomicGeology, v. 103, p. 5-33.

Prior, G.J., Gibson, H.L., Watkinson, D.H., Cook, R.E., andHannington, M.D., 1999, Rare earth and high field strengthelement geochemistry of the Kidd Creek rhyolites, Abitibigreenstone belt, Canada: Evidence for Archean felsic vol-canism and volcanogenic massive sulfide ore formation inan Iceland-style rift environment, in The Giant Kidd CreekVolcanogenic Massive Sulfide Deposit, Western Abitibi

Subprovince, Canada, (eds.) M.D. Hannington and C.T.Barrie; Economic Geology, Monograph 10, p. 457-483.

Relvas, J.M.R.S., Barriga, F.J.A.S., Ferreira, A., Noiva, P.C.,Pacheco, N., and Barriga, G., 2006, Hydrothermal alterationand mineralization in the Neves-Corvo volcanic-hostedmassive sulfide deposit, Portugal, Part I. Geology, mineral-ogy, and geochemistry; Economic Geology, v. 101, p. 753-790.

Rhodes, J.M., Morgan, C., and Liias, R.A., 1990, Geochemistry ofAxial Seamount lavas; magmatic relationship between theCobb hotspot and the Juan de Fuca Ridge; Journal ofGeophysical Research, v. 95, p. 12,713-12,733.

Richards, H.G., Cann, J.R., and Jensenius, J., 1989, Mineralogicalzonation and metasomatism of the alteration pipes of Cyprussulfide deposits; Economic Geology, v. 84, p. 91-115.

Richardson, C.J., Cann, J.R., Richards, H.G., and Cowan, J.G.,1987, Metal-depleted root zones of the Troodos ore-form-ing hydrothermal systems, Cyprus; Earth and PlanetaryScience Letters, v. 84, p. 243-253.

Riverin, G. and Hodgson, C.J., 1980, Wall-rock alteration at theMillenbach Cu-Zn mine, Noranda, Quebec; EconomicGeology, v. 75, p. 424-444.

Robinson, M., Godwin, C.I., and Stanley, C.R., 1996, Geology, lith-ogeochemistry, and alteration of the Battle volcanogenicmassive sulfide zone, Buttle Lake mining camp, VancouverIsland, British Columbia; Economic Geology, v. 91, p. 527-548.

Rogers, N. and van Staal, C.R., 2003, Volcanology and tectonic set-ting of the northern Bathurst mining camp; Part II, Maficvolcanic constraints on back-arc opening, in MassiveSulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine, (eds.) W.D. Goodfellow,S.R. McCutcheon, and J.M. Peter; Society of EconomicGeologists, Monograph 11, p. 181-201.

Rogers, N., van Staal, C.R., and Theriault, R., 2003, Volcanologyand tectonic setting of the northern Bathurst mining camp;Part 1, Extension and rifting of the Popelogan Arc, inMassive Sulfide Deposits of the Bathurst Mining Camp,New Brunswick, and Northern Maine, (eds.) W.D.Goodfellow, S.R. McCutcheon, and J.M. Peter; Society ofEconomic Geologists, Monograph 11, p. 157-179.

Rogers, N. W., MacLeod, C.J.M., Murton, B.J., 1989, Petrogenesisof boninitic lavas from the Limassol Forest Complex,Cyprus, in Boninites and Related Rocks, (ed.) A.J.Crawford; Unwin Hyman, London, p. 288.

Ruks, T. W., Piercey, S.J., Ryan, J.J., Villeneuve, M.E., and Creaser,R.A., 2006, Mid- to Late Paleozoic K-Feldspar Augengranitoids of the Yukon-Tanana Terrane, Yukon, Canada:Implications for crustal growth and tectonic evolution ofthe Northern Cordillera; Geological Society of AmericaBulletin, v. 118, p. 1212-1231.

Saccocia, P.J. and Seyfried, W.E., Jr., 1994, The solubility of chlo-rite solid solutions in 3.2 wt% NaCl fluids from 300-400ºC,500 bars; Geochimica et Cosmochimica Acta, v. 58, p. 567-585.

Saccocia, P.J., Ding, K., Berndt, M.E., Seewald, J.S., and Seyfried,W.E., Jr., 1994, Experimental and theoretical perspectiveson crustal alteration at mid-ocean ridges, in Alteration andAlteration Processes Associated with Ore-FormingSystems, (ed.) D.R. Lentz; Geological Association ofCanada, Short Course Notes, v. 11, p. 403-431.

Saeki, Y., and Date, J., 1980, Computer application to the alterationdata of the footwall dacite lava at the Ezuri Kuroko deposits,Akito Prefecture; Mining Geology, v. 30, p. 241-250.

Santaguida, F., 2000, The Paragenetic Relationships of Epidote-Quartz Hydrothermal Alteration within the Noranda

Volcanic Complex, Quebec; Ph.D. thesis, CarletonUniversity, Ottawa, Ontario, 302 p.

Saunders, A.D., Fornari, D.J., Joron, J.-L., Tarney, J., and Treuil,M., 1982, Geochemistry of basic igneous rocks, Gulf ofCalifornia, Deep Sea Drilling Project Leg 64; InitialReports of the Deep Sea Drilling Project, v. 64, p. 595-642.

Schiffman, P. and Smith, B.M., 1988, Petrology and oxygen isotopegeochemistry of a fossil seawater hydrothermal systemwithin the Solea Graben, northern Troodos Ophiolite,Cyprus; Journal of Geophysical Research, v. 93, p. 4612-4624.

Scott, S.D., 1997, Submarine hydrothermal systems and deposits,in Geochemistry of Hydrothermal Ore Deposits, 3rdEdition, (ed.) H.L. Barnes; John Wiley and Sons Ltd., NewYork, p. 797-875.

Sebert, C. and Barrett, T.J., 1996, Stratigraphy, alteration, and min-eralization at the Tulsequah chief massive sulfide deposit,northwestern British Columbia; Exploration and MiningGeology, v. 5, p. 281-308.

Sebert, C., Hunt, J.A., and Foreman, I., 2004, Geology andLithogeochemistry of the Fyre Lake Copper-Cobalt-GoldSulphide-Magnetite Deposit, southeastern Yukon; YukonGeological Survey, Open File 2004-17, 46 p.

Setterfield, T.N., Hodder, R. W., Gibson, H.L., and Watkins, J.J.,1995, The McDougall-Despina fault set, Noranda, Quebec;evidence for fault-controlled volcanism and hydrothermalfluid flow; Exploration and Mining Geology, v. 4, p. 381-393.

Shinjo, R., Chung, S.-L., Kato, Y., and Kimura, M., 1999,Geochemical and Sr-Nd isotopic characteristics of volcanicrocks from the Okinawa Trough and Ryukyu Arc; implica-tions for the evolution of a young, intracontinental back arcbasin; Journal of Geophysical Research, v. 104, p. 591-610.

Shinjo, R., and Kato, Y., 2000, Geochemical constraints on the ori-gin of bimodal magmatism at the Okinawa Trough, anincipient back-arc basin; Lithos, v. 54, p. 117-137.

Sinton, J.M., Ford, L.L., Chappell, B., and McCulloch, M.T., 2003,Magma genesis and mantle heterogeneity in the Manusback-arc basin, Papua New Guinea; Journal of Petrology, v. 44, p. 159-195.

Skirrow, R.G., and Franklin, J.M., 1994, Silicification and metalleaching in semiconformable alteration beneath the ChiselLake massive sulfide deposit, Snow Lake, Manitoba;Economic Geology, v. 89, p. 31-50.

Smith, S.E. and Humphris, S.E., 1998, Geochemistry of basalticrocks from the TAG hydrothermal mound (26º 08’), Mid-Atlantic Ridge; Proceedings of the Ocean Drilling Program,Scientific Results, v. 158, p. 213-229.

Spitz, G. and Darling, R., 1978, Major and minor element lithogeo-chemical anomalies surrounding the Louvem copperdeposit, Val d’Or, Quebec; Canadian Journal of EarthSciences, v. 15, p. 1161-1169.

Spooner, E.T.C. and Gale, N.H., 1982, Pb isotopic composition ofophiolitic volcanogenic sulphide deposits, TroodosComplex, Cyprus; Nature, v. 296, p. 239-242.

Spry, P.G., Peter, J.M., and Slack, J.F., 2000, Meta-exhalites asexploration guides to ore, in Metamorphosed andMetamorphogenic Ore Deposits, (eds.) P.G. Spry, B.Marshall, and F.M. Vokes; Society of Economic Geologists,Reviews in Economic Geology, v. 11 p. 163-201.

Squires, G.C., Brace, T.D., and Hussey, A.M., 2001,Newfoundland’s polymetallic Duck Pond deposit: EarliestIapetan VMS mineralization formed within a sub-seafloor,carbonate-rich alteration system, in Geology and MineralDeposits of the Northern Dunnage Zone, NewfoundlandAppalachians, (eds.) D.T.W. Evans and A. Kerr; Geological


37

Association of Canada/Mineralogical Association ofCanada, St. John’s, NL, Field Trip Guide A2, p. 167-187.

Stakes, D.S. and Franklin, J.M., 1994, Petrology of igneous rocks atMiddle Valley, Juan de Fuca Ridge; Proceedings of theOcean Drilling Program, Scientific Results, v. 139, p. 79-102.

Stanley, C.R. and Madeisky, H.E., 1994, Lithogeochemical explo-ration for hydrothermal ore deposits using Pearce ElementRatio analysis, in Alteration and Alteration ProcessesAssociated with Ore-Forming Systems, (ed.) D.R. Lentz;Geological Association of Canada, Short Course Notes, v. 11, p. 193-211.

Stern, R.A., Syme, E.C., Bailes, A.H., and Lucas, S.B., 1995,Paleoproterozoic (1.90-1.86 Ga) arc volcanism in the FlinFlon Belt, Trans-Hudson Orogen, Canada; Contributions toMineralogy and Petrology, v. 119, p. 117-141.

Stern, R.J. and Bloomer, S.H., 1992, Subduction zone infancy;examples from the Eocene Izu-Bonin-Mariana and JurassicCalifornia arcs; Geological Society of America Bulletin, v. 104, p. 1621-1636.

Stix, J., Kennedy, B., Hannington, M., Gibson, H., Fiske, R.,Mueller, W., and Franklin, J., 2003, Caldera-formingprocesses and the origin of submarine volcanogenic mas-sive sulfide deposits; Geology, v. 31, p. 375-378.

Stolz, A.J., 1995, Geochemistry of the Mount Windsor Volcanics;implications for the tectonic setting of Cambro-Ordovicianvolcanic-hosted massive sulfide mineralization in north-eastern Australia; Economic Geology, v. 90, p. 1080-1097.

Stoltz, A.J., Varne, R., Davies, G.R., Wheller, G.E., and Foden, J.D.,1990, Magma source components in an arc-continent colli-sion zone: The Flores-Lembata sector, Sunda Arc,Indonesia; Contributions to Mineralogy and Petrology, v. 105, p. 585-601.

Sun, S.-s. and McDonough, W.F., 1989, Chemical and isotopic sys-tematics of oceanic basalts: Implications for mantle com-position and processes, inMagmatism in the Ocean Basins,(eds.) A.D. Saunders and M.J. Norry; Geological Society ofLondon, Special Publication No. 42, p. 313-345.

Swinden, H.S., 1991, Paleotectonic settings of volcanogenic mas-sive sulfide deposits in the Dunnage Zone, NewfoundlandAppalachians; Canadian Institute of Mining and MetallurgyBulletin, v. 84, p. 59-89.

Swinden, H.S., 1996, The application of volcanic geochemistry inthe metallogeny of volcanic-hosted sulfide deposits in cen-tral Newfoundland, in Trace Element Geochemistry ofVolcanic Rocks: Applications for Massive SulfideExploration, (ed.) D.A. Wyman; Geological Association ofCanada, Short Course Notes, v. 12, p. 329-358.

Swinden, H.S., Jenner, G.A., Kean, B.F., and Evans, D.T. W., 1989,Volcanic rock geochemistry as a guide for massive sulfideexploration in central Newfoundland, in Current Research;Newfoundland Department of Mines, Report 89-1, p. 201-219.

Sylvester, P.J. (ed.), 2001, Laser-Ablation-ICP-MS in the EarthSciences; Principles and Applications; MineralogicalAssociation of Canada, 243 p.

Syme, E.C., 1998, Ore-Associated and Barren Rhyolites in the cen-tral Flin Flon Belt: Case Study of the Flin Flon MineSequence; Manitoba Energy and Mines, Open File ReportOF98-9, 32 p.

Syme, E.C. and Bailes, A.H., 1993, Stratigraphic and tectonic set-ting of early Proterozoic volcanogenic massive sulfidedeposits, Flin Flon, Manitoba; Economic Geology, v. 88, p. 566-589.

Syme, E.C., Lucas, S.B., Bailes, A.H., and Stern, R.A., 1999,Contrasting arc and MORB-like assemblages in thePaleoproterozoic Flin Flon Belt, Manitoba, and the role ofintra-arc extension in localizing volcanic-hosted massivesulfide deposits; Canadian Journal of Earth Sciences, v. 36,p. 1767-1788.

Taylor, B.E. and South, B.C., 1985, Regional stable isotope sys-tematics of hydrothermal alteration and massive sulfidedeposition in the West Shasta District, California;Economic Geology, v. 80, p. 2149-2163.

Urabe, T. and Scott, S.D., 1983, Geology and footwall alteration ofthe South Bay massive sulphide deposit, northwesternOntario, Canada; Canadian Journal of Earth Sciences, v. 20,p. 1862-1879.

Urabe, T., Scott, S.D., and Hattori, K., 1983, A comparison of foot-wall-rock alteration and geothermal systems beneath someJapanese and Canadian volcanogenic massive sulfidedeposit, in The Kuroko and Related Volcanogenic MassiveSulfide Deposits, (eds.) H. Ohmoto and B.J. Skinner;Economic Geology, Monograph 5, p. 345-364.

van der Laan, S.R., Arculus, R.J., Pearce, J.A., and Murton, B.J.,1992, Petrography, mineral chemistry, and phase relationsof the basement boninite series of Site 786, Izu-Bonin fore-arc; Proceedings of the Ocean Drilling Program, ScientificResults, v. 125, p. 171-201.

van Staal, C.R., Winchester, J.A., and Bédard, J.H., 1991,Geochemical variations in Middle Ordovician volcanicrocks of the northern Miramichi Highlands and their tec-tonic significance; Canadian Journal of Earth Sciences, v. 28, p. 1031-1049.

Vearncombe, S. and Kerrich, R., 1999, Geochemistry and geody-namic setting of volcanic and plutonic rocks associatedwith early Archaean volcanogenic massive sulfide mineral-ization, Pilbara Craton; Precambrian Research, v. 98, p. 243-270.

Watanabe, M. and Sakai, H., 1983, Stable isotope geochemistry ofsulfates from the Neogene ore deposits in the Green tuffregion, Japan, in The Kuroko and Related VolcanogenicMassive Sulfide Deposits, (eds.) H. Ohmoto and B.J.Skinner; Economic Geology, Monograph 5, p. 282-291.

Wyman, D.A., Bleeker, W., and Kerrich, R., 1999, A 2 7 Ga komati-ite, low Ti tholeiite, arc tholeiite transition, and inferredproto-arc geodynamic setting of the Kidd Creek Deposit;evidence from precise trace element data, in The GiantKidd Creek Volcanogenic Massive Sulfide Deposit,Western Abitibi Subprovince, Canada, (eds.) M.D.Hannington and B.T. Barrie; Economic Geology,Monograph 10, p. 511-528.

Zierenberg, R.A., Shanks, W.C., III, Seyfried, W.E., Jr., Koski,R.A., and Strickler, M.D., 1988, Mineralization, alteration,and hydrothermal metamorphism of the ophiolite-hostedTurner-Albright sulfide deposit, southwestern Oregon;Journal of Geophysical Research, v. 93, p. 4657-4674.

S. J. Piercey

38

Submarine Volcanism and Mineralization: Modern through Ancient

156

Fig

ure

3-c

14.

Petr

ochem

ical assem

bla

ges f

or

various v

olc

anogenic

massiv

e s

ulp

hid

e d

eposit e

nvironm

ents

and d

eposit t

ypes.

Based o

n c

oncepts

pre

sente

d h

ere

in a

nd P

ierc

ey (

2007).

BO

N=

bonin

ite;

HF

SE

= h

igh f

ield

str

ength

ele

ments

; IA

T =

isla

nd a

rc t

hole

iite;

LO

TI

= low

-Ti is

land a

rc t

hole

iite;

OIB

= o

cean isla

nd b

asalt;

MO

RB

= m

id-o

cean r

idge b

asalt;

see t

ext

for

a d

iscus-

sio

n o

f F

II a

nd F

III

rhyolit

e.

BO

N (+

/-LO

TI)

orM

OR

B

MO

RB

or

BO

N (+

/-LO

TI)

MO

RB

/BO

N

Fe-T

iIc

elan

dite

Mafi

cM

afic

Silic

icla

stic

Cypr

usO

man

Bay

of I

slan

dsSl

ide

Mou

ntai

n

Bes

shi

Win

dy C

ragg

yFy

re L

ake

Out

okum

pu

MO

RB

OIB

(+/-

BO

N)

MO

RB

(+/-

BO

N)

Bim

odal

Mafi

c

Nor

anda

Flin

Flo

nK

idd

Cre

ekRa

mbl

er

IAT/

LOTI

BO

NM

OR

B

KOM

BO

N

FIII

- FII-

FIV

BO

N/T

HO

Lrh

yolit

esFe-T

iIc

elan

dite

MO

RB

Bim

odal

Fels

ic

Kur

oko

Buc

hans

Mou

nt R

ead

Eska

y C

reek

FIII

- FII

(HFS

E en

rich

ed to

calc

-alk

alic

tope

ralk

alic

)fe

lsic

OIB

, MO

RB

MO

RB

Fels

icSi

licic

last

ic

Bat

hurs

tIb

eria

n P

yrit

e B

elt

Finl

ayso

n La

ke

VVV

VVV

VV

VV

VV

VVV

V

VV

VV

VV

V

V

V

FIII

- FII

(HFS

E en

rich

ed to

calc

-alk

alic

tope

ralk

alic

)fe

lsic

OIB

, MO

RB

MO

RB

Ult

ram

afic

rock

sSe

dim

enta

ry ro

cks

Fels

ic v

olca

nic

rock

s

Icel

andi

teFe

lsic

intr

usio

n (h

igh

leve

l)

Mas

sive

sul

phid

e de

posi

t

Fels

ic in

trus

ion

(dee

p se

ated

)

MO

RB

Gab

bro

Shee

ted

mafi

c dy

kes

Bas

alt

V VVV V

Colour Figures

157

-800

-600

-400

-400

-600

-400

0 1 2

kilometres

155º56'0"W 155º54'0"W

20º4

6'0"

N20

º44'

0"N

Figure 4-c5. Cluster of steep-sided cones on the Hana Ridge, thesubmarine east rift zone of Haleakala Volcano, Hawaii (Clague et al.,2000b). The cones have aspect ratios averaging 0.18, heights ofseveral hundred metres, and their bases are about 1 km in diameter.Unlike their subaerial counterparts, these submarine cones lacksummit craters; the only one sampled is constructed of alkalic lavas.The 30 kHz bathymetric data are gridded at 30 m (MBARI MappingTeam, 2000) and shown with 200 m contours. This and most of thesubsequent figures are slope-shaded bathymetry; most of the datawas collected with hull-mounted multibeam systems. Slope-shadingis a technique that shades depending on the slope of the surfacerather than illuminating from one direction.

-1570

-1550

-1540

-1530

0 100 200

metres

130º1'50"W 130º1'45"W

45º5

8'40

"N45

º58'

35"N

45º5

8'30

"N

Figure 4-c6. A 200 m diameter cone on the floor of Axial Seamounton the Juan de Fuca Ridge (Thomas et al., 2006). The cone has adeep crater reaching almost to the regional depth surrounding thecone. The lumpy terrain on the western flank may be constructionalor may be slump deposits from a collapse of part of the cone. The200 kHz bathymetric data was collected with the autonomousMBARI mapping vehicle (AUV) D. Allan B. flying at 50 m altitude. Thedata are gridded at 1 m and shown with 10 m contours. This conewas previously imaged by side-scan sonar (Embley et al., 1990).

Increase in Eu/Eu*of Fe-Si cherts

Ba/Sr increasesTl+Sb increases

Limit of Tl halo

Mn content of carbonate increases

S/Na2O increases

AI increases

CCPI increasesδ18O decreases

Limit of Na depletion

Hanging-wall volcanic rocks

Massive sulphide

Exhalites (ore-equivalent horizon)

Footwall volcanic rocks

Chlorite alteration

Sericite alteration

Carbonate alteration

Albite alteration

Quartz alteration

Figure 3-c15. Model of alteration zonation associated with Zn-rich polymetallic volcanogenic hydrothermal massive sulphide deposits and alter-ation vectors useful for exploration (from Large et al., 2001c). CCPI = chlorite-carbonate-pyrite index.

LITHOGEOCHEMISTRY OF VOLCANIC ROCKS … · Volcanogenic massive sulphide (VMS) deposits have ... 1)...

Documents

Transcript of LITHOGEOCHEMISTRY OF VOLCANIC ROCKS … · Volcanogenic massive sulphide (VMS) deposits have ... 1)...