Ore Geology Reviews 37 (2010) 158–174

Contents lists available at ScienceDirect

Ore Geology Reviews

j ourna l homepage: www.e lsev ie r.com/ locate /oregeorev

Geochemistry and geochronology of the volcanic rocks associated with the Dong'anadularia–sericite epithermal gold deposit, Lesser Hinggan Range, Heilongjiangprovince, NE China: Constraints on the metallogenesis

Zhaochong Zhang a,⁎, Jingwen Mao b, Yanbin Wang c, Franco Pirajno d,e, Junlai Liu a, Zhidan Zhao a

a State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, PR Chinab MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing, 100037, PR Chinac Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, PR Chinad Geological Survey of Western Australia, 100 Plain Street, East Perth WA 6004, Australiae School of Earth and Environment, The University of Western Australia, Crawley 6009, Australia

⁎ Corresponding author. Tel.: +86 10 82322195; fax:E-mail address: zczhang@cugb.edu.cn (Z. Zhang).

0169-1368/$ – see front matter © 2010 Elsevier B.V. Adoi:10.1016/j.oregeorev.2010.03.001

a b s t r a c t

a r t i c l e i n f o

Article history:Received 1 July 2009Received in revised form 11 March 2010Accepted 11 March 2010Available online 18 March 2010

Keywords:Dong'anEpithermal goldGeochronologyExtensional settingNE China

Late Mesozoic volcanism is widespread throughout NE China. On the basis of lithological associations andspatial relationships, the volcanic rocks in the Lesser Hinggan Range can be divided into two formations, i.e.,felsic-dominant Fuminghe Formation and overlying mafic-dominant Ganhe Formation. The Dong'an golddeposit, a typical adularia–sericite epithermal system, is spatially closely associated with rhyolitic porphyry,which is a subvolcanic intrusion of the Fuminghe Formation. Total measured, indicated, and inferredresources for the Dong'an deposit are 70 tonnes (2.25 Moz) of gold with the grade of 5.04 g/t Au, making itone of the largest epithermal gold deposits in China.SHRIMP U–Pb zircon and 40Ar/39Ar geochronology applied to one rhyolitic porphyry sample and sericiteseparated from auriferous quartz veins of the main mineralization stage were carried out to constrainmagmatic and hydrothermal events. The results suggest that the mineralization age of 107.2±0.6 Maoverlaps with the age of the rhyolitic porphyry 108.1±2.4 Ma. Our new age data indicate that there was apreviously unrecognized mineralization event in NE China at 107–108 Ma.Systematic geochemical investigations on the volcanic rocks in the Lesser Hinggan Range show that bothFuminghe and Ganhe Formations are characterized by significant large ion lithophile elements (LILE) andlight rare earth elements (LREE) enrichment coupled with high field strength elements (HFSE) depletion, butthey have distinct Sr and Nd isotopic compositions. The Fuminghe Formation has relative high 87Sr/86Srratios of 0.707253 to 0.707373, and negative εNd(t) values of −2.78 to −3.05 (t=108 Ma), whereas theGanhe Formation displays slightly lower 87Sr/86Sr range of 0.705434–0.705763 and positive εNd(t) values of+0.76 to +1.83. These geochemical data suggest that the rhyolitic magmas of the Fuminghe Formationprobably represent the final differentiates of parental andesitic magmas, resulted from the partial melting ofmafic lower crust, whereas the volcanic rocks of the Ganhe Formation were produced by fractionation ofbasaltic magmas generated from partial melting of a mixture of an incompatible element depletedanhydrous lherzolite asthenospheric mantle source and a hydrous enriched lithospheric mantle source in anextensional tectonic setting, in response to upwelling of asthenospheric mantle. The rhyolite porphyries ofthe Fuminghe Formation are inferred to have supplied heat that drove the convective hydrothermal systemat Dong'an deposit, but also provided some of the fluid sources responsible for the development of theDong'an epithermal system.

+86 10 82322175.

ll rights reserved.

© 2010 Elsevier B.V. All rights reserved.

1. Introduction

Dong'an is an adularia–sericite epithermal gold deposit (Hayba et al.,1985; Heald et al., 1987; Simmons et al., 2005), which resulted fromhydrothermal activity associated with an Early Cretaceous subvolcanic

intrusion that belongs to a high K calc-alkaline to shoshonite volcanicseries in NE China. The deposit is located in Xunke county, near theRussian border, ∼500 km north of the city of Harbin, Heilongjiangprovince, NE China. Except for gold geochemical anomalies and somesmall skarn Cudeposits, the areawas not known for goldmineralizationuntil the discovery of theDong'an gold deposit in 2000. The geology andmineralization in the area is poorly understood, because of dense forestcover. Discovery was by the Heilongjiang Academy of GeologicalExploration for Nonferrous Metals (HAGENM) during a follow up of

159Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

gold geochemical anomalies in soils. Total measured, indicated, andinferred resources for the Dong'an deposit are currently 14 Mt of oregrading 5.04 g/t Au and 82.74 g/t Ag, or 2.25 Moz Au and 37 Moz Ag(HAGENM, 2001). A detailed exploration program is still being carriedout byHAGENMatDong'an and adjacent areas, which are considered tohave good exploration potential by the HAGENM teams and Su et al.(2006).

Dong'an is the first gold deposit recognized in eastern China thatcontainsa largequantity of adularia, even thoughmanyother epithermalgold deposits in the region have been classified as adularia–sericite type(Mao et al., 2007). Although aspects of the geology and geochemistry ofthe Dong'an gold deposit, e.g., fluid inclusion and H and O isotopegeochemistry as well as S and Pb isotope composition of sulfides, havebeen previously studied (e.g., Guo et al., 2004; Su et al., 2006; Yang,2008), themetallogenesis is still poorly understood, andnowork has yetbeen published in English. In this paper, we provide an overview of thedeposit geology, combinedwith geochronological (SHRIMPU–Pb zirconand 40Ar/39Ar) andwhole rock geochemical data of the host subvolcanicand volcanic rocks in order to characterize the Dong'an ore-formingsystem.

2. Regional geological setting

The Dong'an gold deposit is located in the Lesser Hinggan Range inNE China, south of the suture between the North China craton and theSiberia craton and north of the Solonker–Xilinhot–Hegenshan faultsystem (Fig. 1a). The latter is a major and complex suture zonebetween the northern margin of the North China Craton and theMongolian plate, characterized by Mid-Ordovician–Early Siluriansubduction–accretion complexes, ophiolite belts and Andean-typemagmatic arcs (Xiao et al., 2003; de Jong et al., 2006). The ophiolitesuites indicate multi-stage oceanic subduction and continent-arccollision related to the closure of the paleo-Asian and Mongolia–Okhotsk Oceans (Xiao et al., 2003). The orogenic belt was uplifted atthe end of the late Carboniferous due to extensive emplacement ofHercynian granitic plutons (BGMRNM, 1991). Since the Mid-Jurassic,oblique subduction of the Izanagi–Pacific plate under the easternmargin of Eastern China continent has led to the formation of theNNE-trending Mesozoic magmatic belts, NNE-strike–slip faults, and abasin and range style tectonics (Ren et al., 1990; Zhou et al., 2002).

According to previous work (e.g., Han et al., 1995; Yin and Ran,1997), the stratigraphic sequence in the Lesser Hinggan Rangecomprises four tectonostratigraphic units (Fig. 1b), namely: 1)Precambrian metamorphic basement, 2) Cambrian and Permiansubmarine sedimentary cover, 3) Jurassic to Cretaceous terrigenousclastic and volcanic rocks, and 4) Cenozoic coarse clastic andcontinental basaltic rocks. The Precambrian metamorphic rocks, areuncommon, and consist of schist, phyllite, and meta-felsic rocks.Cambrian strata include dolomitic marble, phyllite and carbonaceousslate, discordantly overlying the Precambrian metamorphic rocks.Permian low-grade metamorphic clastic rocks (e.g., sandstone,conglomerate and shale) discordantly overlie the Cambrian strata.The Permian strata, in turn, are discordantly overlain by Early Jurassicterrigenous clastic rocks, consisting of granitic conglomerate, sand-stone, siltstone, and tuff sandstone intercalated with coal seams. EarlyCretaceous volcanic rocks, extensively distributed throughout thewhole belt, comprise a wide spectrum of rock types, includingbasaltic, trachyandesitic, and rhyolitic lava flows and rhyolitic tuffintercalated with rhyolitic perlite. Oligocene–Pliocene sandstone andconglomerate are also extensively distributed throughout the wholebelt, and cover all the Pre-Cenozoic strata. Quaternary alkaline basalts,which are a part of rift-related Cenozoic volcanic rock belt in easternChina, and outcropping along valleys.

On the basis of lithological associations and relationships, the EarlyCretaceous volcanic sequences can be divided into two formations:Fuminhe (FM) and Ganhe (GH) Formations. The FM is composed

predominantly of a 120 to 300 m-thick succession of rhyolitic anddacitic lava flows and welded tuff intercalated with breccia-bearingtuff and perlite, minor andesite and trachyandesite. The rhyolitesshow a sub-aphyric to weakly porphyritic and spherulitic texture witha few phenocrysts of oligoclase, sanidine and quartz of about 0.2 to1.0 mm in size. The matrix consists of microcrystalline felsic minerals,glass and lesser zircon and apatite. The GH is 75 to 380 m thick andconsists mainly of pyroxene-phyric basalt, basaltic andesite, trachyan-desite and andesite with rhyolitic breccias at the bottom, conformablyoverlying FM.However, a gap in volcanic activity exists, as indicatedbya1–2 m thick weathering crust developed on the rhyolites (Fig. 2).Basaltic rocks are commonly porphyritic and rarely vesicular. Thepredominant phenocrysts are labradorite and clinopyroxene, 0.5–1 mmin size, with rare olivine, orthopyroxene and amphibole. The ground-mass consists of plagioclase laths and clinopyroxene grains less than0.1 mm, with intergranular opaque or interstitial glass.

3. Geology of the Dong'an deposit

The Dong'an region is underlain by FM Early Cretaceous volcanicrocks and Oligocene–Pliocene sandstone and conglomerate, almost allof which have been covered by Quaternary sediments. In the Dong'anarea, FM consists predominantly of rhyolitic lava and rhyolitic tuffwith minor dacite, overlying a Late Triassic coarse-grained alkali-feldspar granitic intrusion, which is also intruded by Cretaceous fine-grained alkali-feldspar granite stock (Fig. 1c). Rhyolitic porphyrydykes intruded the volcanic sequence and the Triassic graniticintrusion (Fig. 1c). The Dong'an area is characterized by a series oftensile-shear NS-, NE- and NNE-trending faults (Fig. 1c).

The 14 gold orebodies, associated with quartz- and sericite-dominated alteration zones recognized in the mine are controlled byNS- and NE-striking faults, dipping NW at 70° to 85° (Fig. 3). Eight ofthe orebodies are hosted in rhyolitic lavas, five are hosted in rhyoliticporphyry dykes, and one is hosted in Triassic alkali- feldspar granite.However, almost all gold orebodies are not far from rhyoliteporphyries (Fig. 1c). In general, the country rocks and gold orebodieshave distinct boundaries which are characterized by alteration zonesalong faults. Breccias within gold orebodies are commonly recognized(Fig. 4a), and the breccias strike consistently with the faults (Fig. 1c).The size of gold ore veins varies considerably, from 50 to 800 m inlength and 1 to 7 m in thickness; they extend to depths of less than400 m (Fig. 3), with grades of 3–10 g/t Au. The largest vein is 770 mlong, 6.70 m thick on average, and has a vertical extent of 358 m, withan average grade of 9.05 g/t Au and 75.8 g/t Ag. The Au and Ag gradesshow a positive correlation with one another.

Pyrite, galena, chalcopyrite, chalcocite, sphalerite, arsenopyrite,magnetite, electrum and native silver are present in the ores. Mostof ore minerals are predominantly anhedral grains, although somedisplay euhedral or subhedral textures. Quartz, adularia, sericite andfluorite are the most abundant gangue minerals and generally occuras fine-grained assemblages; some are, however, medium- andmicrograined assemblages. The ore minerals are predominantlydistributed as sparse disseminations, locally as dense disseminations,or as veinlets and stockwork veins. In contrast, the gangue mineralsoccur as massive, banded, brecciated, vuggy structures, in places withcomb and bladed textures.

Sulfides are the major ore minerals, but they generally account forless than 4% of the ore by volume. Pyrite is the most abundant sulfidecoexisting with minor chalcopyrite, galena and hematite. ICP-AESanalyses of pyrite indicate that the Au and Ag contents range from12.8 to 295.2 ppm and 2.6 to 233.3 ppm, respectively, but As contentsare below detection level (b0.5 ppm, Guo et al., 2004). Most goldgrains are irregular and range in size from 20 to 30 µm up to 100 µmin diameter. They are distributed along quartz crystal boundaries,although lesser amounts of gold are observed filling fractures andcavities in quartz, or are enclosed in pyrite. Electron microprobe

160 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

Fig. 2. Simplified stratigraphic column of the Lesser Hinggan Range region, Heilongjiang province with sample locations.

161Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

analyses indicate that the composition of the grains is from 50.1 to65.1 wt.%, i.e., corresponding to electrum (Guo et al., 2004).

According to Guo et al. (2004), the gold mineralization was formed inthree stages. Stage 1 is represented by weakly auriferous (0.2–0.4 g/t Au)pervasive quartz with weak chlorite–sericite–pyrite alteration as minorveinlets. During this stage, rhyolite and Triassic granite were locallyreplaced by disseminated low-temperature quartz and chalcedonicquartz. Stage 2 is characterized by an intense distribution of whitemassive quartz veins, stockwork veins, and hydrothermal breccias(Fig. 4a), containing variable amounts of quartz, adularia and sericite(Fig. 4b). Cryptocrystalline, chalcedonic quartz is present near the surface,whereas subhedral and anhedral quartz crystals developed at deeperlevels. Some relatively low-grade (3–5 g/t Au) mineralization wasformed during this stage. However, stage 3 is the most important stageof gold mineralization. It is characterized by extensive grey-white veins,

Fig. 1. (a) Simplified tectonic map of NE China (modified from Fan et al., 2003). (b) Distrib(modified from Ma et al., 2002). (c) Sketch geological map of the Dong'an district (modified40Ar/39Ar and SHRIMP U–Pb zircon dating, respectively.

stockwork veins, veinlets with quartz-, adularia- and sericite-dominated,which overprint the previously emplaced stockwork of stage 2 (Fig. 4c).Some sulfides (pyrite, chalcopyrite, galena) and hematite are commonlyassociated with quartz, sericite, adularia and chlorite veins. The gradeof this stage is generally N5 g/t Au. The mineral paragenesis is shownin Fig. 5.

Based on previous works (e.g., Guo et al., 2004) and our fieldobservations, the wall–rock alteration minerals in the Dong'an golddeposit include quartz, adularia, sericite and fluorite, accompanied bylesser amounts of pyrite, chlorite and carbonate. The quartz, adularia,sericite and pyrite alteration is spatially and temporally closelyassociated with gold mineralization. This hydrothermal alteration ismainly developed along faults and in breccias, and exhibits a clearconcentric zoning pattern, from a central zone with a mineralassemblage of quartz, chalcedonic quartz, sericite, adularia, chlorite

ution of late Mesozoic volcanic rocks in the Lesser Hinggan Range and adjacent areasfrom Guo et al., 2004). The yellow and red circles represent the sampling localities for

162 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

and pyrite, to envelopes of veining and stockworks containing amineral assemblage of quartz, kaolinite, sericite, adularia and fluorite.

Adularia is the most important feature in the Dong'an gold depositand occurs widely in the form of distinctive light-red-colored veins,0.5 to 1.5 m in width (Fig. 4d). Adularia is commonly closelyassociated with quartz and sericite. Fluorite is also a commonmineral,developed extensively in the mine as veins. It can be divided intothree stages. In the first, fluorite is in subhedral aggregates, associatedwith grey quartz, adularia and chlorite. The second stage is purple incolor, associatedwithwhite quartz, adularia and chlorite (Fig. 4e). Thethird stage is green in color, associated with stockworks and veinlet ofquartz, adularia and chlorite (Fig. 4f). In addition, cubic drusy fluoritesare commonly found in cavities.

Fig. 3. Cross section of the No. 6 prospecting line of t

4. Analytical methods and procedures

4.1. Analytical procedures for Ar–Ar isotope study

One sericite sample (DA05-16) separated from auriferous quartzveins which are dominated by quartz, adularia and sericite of stage 3,was analyzed. Field observations suggest that the original rock ispossibly rhyolite porphyry. The sample was crushed (0.08–0.15 mm)and purified using a magnetic separator and then cleaned by ultrasonictreatment under ethanol. The purity of the mineral separates is betterthan 99%, as checked under the microscope. 40Ar/39Ar analyses werecompleted on a MM-5400 micromass spectrometer at the ChinaUniversity of Geosciences, Beijing. The irradiation duration and neutron

he Dong'an gold deposit (after HAGENM, 2001).

163Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

dose were 9.5 h and 2.08×10−17 neutrons cm−2 for determinedsericites respectively. The J factor was estimated by replicate analysisof Fish Canyon Tuff sanidine with an age of 27.55±0.08 Ma(Lanphere and Baadsgaard, 1997) with 1% relative standard deviation(1σ). Details of the procedure for the 40Ar/39Ar analyses have

Fig. 4. Photographs of representative hand specimens showing the features of the gold oreporphyry are cemented by hydrothermal minerals. (b) Breccia ore with intense white(c) Extensive sulfide-bearing quartz veining, stockworks and veinlets (stage 3), crosscmineralization). (d) Banded quartz-adularia veins with chlorite (green) and some fine graine(green). (f) Green colored fluorite aggregate.

been described by Wang et al. (2002a). 40Ar/39Ar data are listed inTable 1 with errors reported as 1σ. Released spectra are shown inFig. 4. For relatively rapid cooling rates, the estimated closuretemperature for sericite is taken as 400±50 °C (Hames and Bowring,1994).

s in the Dong'an gold deposit. (a) Breccias in which angular clasts of silicified rhyoliticquartz alteration associated with fine-grained sulfides (stage 2 of mineralization).utting previously formed stockwork (containing minor green chlorite, stage 2 ofd sulfides. (e) Purple-colored fluorite associated with white quartz, adularia and chlorite

Fig. 5. Mineral paragenesis scheme for the Dong'an gold deposit.

Table 1Ar–Ar analytical data for sericite separated from the Dongan gold deposit, Heilongjiang province, NE China.

T (°C) (40Ar/39Ar)m (36Ar/39Ar)m (37Ar/39Ar)m F 39Ar(×10−8mol) 39Ar cum. (%) Age (Ma)

700 46.463 0.044 0.202 33.483 0.114 1.48 121.68±3.05820 36.818 0.001 0.142 36.569 0.129 1.68 132.50±2.18900 33.884 0.005 0.032 32.351 2.087 27.16 117.70±1.75940 37.344 0.019 0.000 31.626 1.088 14.16 115.14±1.61980 33.200 0.008 0.001 30.763 0.509 6.62 112.10±1.641020 30.799 0.004 0.021 29.750 1.087 14.15 108.52±1.671060 31.606 0.008 0.009 29.378 0.555 7.23 107.20±1.531110 30.255 0.000 0.003 30.213 0.543 7.07 110.15±1.551160 29.505 0.000 0.012 29.461 0.445 5.79 107.49±1.511220 29.661 0.001 0.053 29.223 0.378 4.92 106.65±1.661280 29.104 0.000 0.010 29.006 0.378 4.92 105.88±1.111340 29.468 0.001 0.055 29.113 0.247 3.21 106.26±1.471400 32.231 0.002 0.615 31.633 0.123 1.61 115.17±1.63

Notes: m is ratio of the measured value; F is the ratio of radiogenic 40Ar to 39Ar; 39Ar (10–8 mol) is 39Ar released for each heating step; 39Ar cum. (%) is cumulative 39Ar (%).

Table 2Zircon SHRIMP U–Pb analytical results for a rhyolite porphyry, DA05-16, from the Dongan gold deposit, Heilongjiang, NE China.

Th (ppm) U (ppm) Th/U 204Pb/206Pb % 206Pb com Total 238U/206Pb ±1σ% Total 207Pb/206Pb ±% Age 206Pb/238U

DA-1.1 120.5 107.86 0.8949 0.0076 11.18 51.9±3.3 0.1363±7.3 109.5±4.3DA-2.1 188.9 151.65 0.8029 0.0042 5.19 54.2±3.1 0.0982±7.6 110.5±3.7DA-3.1 215.7 211.56 0.9809 0.0041 6.14 54.0±3.1 0.0965±8.6 111.3±3.8DA-4.1 82.6 50.68 0.6135 0.0047 15.73 52.3±3.7 0.160±14 105.0±5.6DA-5.1 73.8 47.75 0.6467 0.00065 7.40 54.7±3.8 0.1075±6.1 108.1±4.3DA-6.1 121.5 84.53 0.6956 0.0025 10.35 51.7±3.6 0.1292±6.3 111.1±4.5DA-7.1 207.9 164.54 0.7912 0.0031 7.03 55.2±3.3 0.1050±7.9 107.4±3.8DA-8.1 236.4 159.72 0.6757 0.0020 4.67 56.0±3.3 0.0918±5.7 107.9±3.7DA-9.1 154.9 134.84 0.8708 0.0037 8.93 54.5±3.7 0.127±17 105.7±5.3DA-10.1 139.8 111.18 0.7951 0.0068 14.73 49.1±3.5 0.184±16 108.0±6.7DA-11.1 69.7 45.74 0.6571 0.010 19.72 46.6±4.1 0.251±18 102.1±10.0DA-12.1 328.6 197.84 0.6021 0.0049 7.51 52.2±3.2 0.114±11 112.4±4.3DA-13.1 92.4 59.97 0.6494 0.0019 19.68 46.5±5.2 0.240±20 104.3±10.7DA-14.1 412.5 232.01 0.5625 0.0012 5.37 58.3±3.1 0.0974±4.5 102.8±3.3DA-15.1 78.5 88.29 1.1253 0.0019 28.25 40.7±3.9 0.304±11 106.5±9.9

164 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

Fig. 6. Zircon SHRIMP concordia diagrams and radiometric ages of rhyolite porphyritesample DA05-18. Data-point error ellipse are 68.3% conf.

Fig. 7. 40Ar/39Ar spectra of sericite (sample DA05-16) from auriferous quartz veins of stag

Table 3Major oxide contents (in wt.%) of late Mesozoic volcanic rocks in the Lesser Hinggan Range

Sample Fm. SiO2 TiO2 Al2O3 Fe2O3 FeO MnO MgO

b6108 GM 59.51 0.65 18.1 3.95 1.81 0.12 2.32b5138 58.51 1.14 16.13 1.1 4.62 0.17 3.83b6076 58.45 1.88 16.14 5.52 1.87 0.08 2.21b6077 58.15 1.1 16.19 4.71 3.07 0.07 3.39b5124 57.64 1.79 15.7 1.95 4.87 0.13 1.87b3112 57.07 1.06 15.1 3.63 3.89 0.14 4.83b5140-1 56.15 1.07 14.73 1.8 5.12 0.15 7.00b6082-1 55.94 1.24 19.27 4.63 2.1 0.08 2.02b6069 55.84 1.11 15.67 3.2 4.13 0.15 3.62b607 53.27 1.22 16.43 3.32 4.49 0.23 4.25b5035-2 47.52 2.12 15.64 1.68 8.89 0.2 6.91DA87-2-1 FM 80.74 0.1 9.94 0.06 0.23 0.01 0.02DA87-2 79.52 0.1 10.48 0.04 0.27 0.01 0.01b3064-2 80.15 0.08 11.67 0.37 0.48 0.02 0.05b6074-4 78.11 0.22 10.46 1.91 0.36 0.02 0.02DA06-03 66.46 0.82 18.61 2.46 1.38 0.02 1.13DA06-4 61.24 0.87 19.67 2.11 2.71 0.08 2.24K48-2 62.58 0.49 15.69 1.33 1.96 0.08 1.02b5009-1 69.45 0.62 14.01 4.79 0.59 0.02 0.51b5039 62.63 0.64 17.21 3.88 1.17 0.08 1.4b3113 62.15 0.72 17.58 2.24 1.99 0.12 1.78b2054 61.54 0.7 17.62 2.51 2.3 0.09 2.48b3005-1 60.33 0.73 18.13 4.73 1.00 0.09 1.9

Abbreviations: FM = Fuminghe; GH = Ganhe. LOI = loss on ignition. Mg-number [molar M

165Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

4.2. Analytical procedures for U–Pb zircon chronology

Zircons were obtained from a sample of rhyolitic porphyry spatiallyclosely associated with gold orebody (DA05-18; Fig. 1c) usingconventional heavy-liquid and magnetic separation techniques. Thezircons were mounted in epoxy, polished and coated with gold. Themounts were then photographed in transmitted and reflected light foridentification of analyzed grains. Zircons from the rhyolitic porphyrywere dated on a SHRIMP II unit at the Beijing SHRIMP Center (CAGS).Cathodoluminescence (CL) images were made of the zircons prior toanalysis. The SHRIMP II analyses followed established methods(Williams, 1998; Song et al., 2002). The calibration standard used is aSri Lankan gem zircon standard (SL13), and the internal standard is theAustralian National University zircon standard TEMORA 1 (Black et al.,2003). Datawere corrected for common Pb on the basis of themeasured208Pb/206Pb (zircon) or 207Pb/206Pb, as described in Compston et al.(1992). Due to theyoungage and the lowUcontent of the samples, some

e 3. Abbreviations: PA = preferred age; MSWD = mean square weighted deviation.

, Heilongjiang province, NE China.

CaO Na2O K2O P2O5 H2O+ LOI Total Mg-no.

4.49 3.68 3.04 0.33 2.08 2.43 100.38 0.486.14 3.26 2.48 0.25 1.66 2.89 100.18 0.594.43 3.82 3.3 0.44 1.6 1.49 99.79 0.415.69 3.48 2.08 0.25 1.36 1.80 99.93 0.505.06 3.91 3.54 0.42 0.84 4.83 100.08 0.386.39 2.86 2.16 0.21 1.92 2.11 99.53 0.596.25 2.76 2.27 0.23 1.44 2.80 99.97 0.697.05 4.00 1.71 0.24 1.74 2.37 100.48 0.416.47 3.46 1.95 0.23 1.56 6.04 99.89 0.529.05 3.06 1.53 0.21 1.36 3.92 99.97 0.55

10.58 2.61 0.49 0.28 1.9 3.85 100.32 0.590.02 0.03 8.67 0.02 0.28 0.33 100.17 0.130.02 0.01 9.12 0.02 0.2 0.27 99.85 0.070.11 3.74 2.65 0.01 0.44 0.54 99.86 0.120.02 3.56 4.8 0.04 0.4 0.46 99.96 0.020.32 0.01 5.54 0.3 2.36 4.37 100.52 0.400.48 2.58 4.79 0.34 3.07 3.10 100.37 0.514.37 1.76 5.19 0.19 2.12 7.80 99.78 0.411.63 1.34 4.52 0.22 1.96 2.07 99.77 0.183.43 3.42 4.41 0.32 0.98 095 99.62 0.394.56 3.66 3 0.27 2.02 0.86 100.14 0.494.66 3.82 2.7 0.27 1.74 0.67 100.52 0.544.93 3.77 2.96 0.25 1.06 0.90 100.00 0.44

g/(Mg+Fe2+)]×100, assuming 20% of total iron oxide is ferric.

Fig. 8. (a) SiO2 vs. Na2O+K2O diagram (Le Bas et al., 1986) and (b) K2O vs. SiO2 diagrams(Peccerillo and Taylor, 1976) for the late Mesozoic volcanic rocks in the Lesser HingganRange. The boundary between alkaline and subalkaline series in Fig. 8a is from Irvine andBaragar (1971). All major oxides are LOI-free, normalized to 100%. Full circles – FumingheFormation; empty circles – Ganhe Formation.

166 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

analyses have a high proportion of common Pb. However, in absoluteamount, the common Pb content of the samples is similar to that of thecommon Pb-free standard. This indicates that the common Pb is mainlysurface and instrumental background. None of themean ages calculatedwould change significantly if a different commonPb composition is used.The ages were calculated using ISOPLOT 2.96 (Ludwig, 1998). Uncer-tainties in ages are quoted at the 95% confidence level (2 σ).

4.3. Major, trace element and Sr–Nd isotope analytical methods

Samples were initially checked for weathering and traces ofhydrothermal alterationwere removed before the rockswere reducedto chips. The freshest chips with least apparent alteration wereselected for analysis using a binocular microscope and pulverized intopowders using agate pestles and mortars. Bulk-rock major and traceelement compositions were determined at the Institute of Rock andMineral Analyses, Chinese Academy of Geological Sciences, Beijing.Major element determinations were by X-ray fluorescence spectros-copy using the methods of Norrish and Chappell (1977). Ferric andferrous iron were determined by wet chemical methods. Traceelement abundances were determined by inductively-coupled plasmamass spectrometry (ICP-MS) following the method of Dulski (1994).The precision of the analyses was generally ∼1% for major oxides,∼0.5% for SiO2, and 3–7% for trace elements. Precision values are basedon the average of repeated analysis of standard BHVO-1. Majorelements were measured on Siemens 303AS and 3080E spectrom-eters, and trace elements on VG PQ-2 Turbo and PQ-2S instruments.

Strontium and neodymium isotopic ratios were measured at theInstitute of Geology and Geophysics, Chinese Academy of Sciences (IGG-CAS). Rock chips of−620 mesh were used to perform Sr and Nd isotopeanalysis. Before being ground to 6160mesh in an agatemill anddissolved,the chipswere leached inpurified6 NHCl for 24 hat roomtemperature tominimize the influence of surface alteration or weathering. Nd and Srisotope ratios and associated isotope-dilution concentrations weremeasured at IGG-CAS. Analysis of radiogenic isotopes has been discussedby Harmer et al. (1986), and only a summary is presented here. 87Sr/86Srand 143Nd/144Nd ratios were determined on a VG 354 mass spectrom-eter, and isotopic ratios were normalized to 145Nd144Nd=0.7219 and86Sr/88Sr=0.1194. Repeated analyses of standards yielded averages of0.710240±0.000011 (2σ, n=6) for Sr standard NIST SRM987, and0.511862±0.000010 (2σ, n=6) for the LaJolla Nd standard. Totalchemical blanks were b200 pg for Sr and b50 pg for Nd.

5. Analytical results

5.1. SHRIMP U–Pb zircon and Ar–Ar dating

Regardless of zoning pattern and U–Th content, all 15 analyses ofzircon yielded ages between 102 and 112 Ma (Table 2). The maincluster forms an array in the total 207Pb/206Pb vs. total 238U/206Pbdiagram along a regression line to common Pb (Fig. 6). The interceptof this regression line defines a mean age of 108.1±2.4 Ma. The highpercentage of common Pb in some of the analyses is due to low Ucontent and thus low amount of radiogenic Pb in the zircon (seeanalytical techniques for more details on common Pb correction).According to Wingate and Compston (2000), 206Pb/238U measured onzircon can vary significantly with the relative orientation of thedifferent crystals analyzed, because of channeling of primary ions,emission of secondary ions along preferred directions and differentialionization of secondary species. In our data set, however, fourteenanalyses yielded little scatter in 206Pb/238U (2σ error on themean=2.4). A good statistical fit was also found in the unknown(MSWD=0.45). This suggests that the dispersion of Pb–U ratio in thedata set is limited and the age of the samples is accurate.

Results of Ar–Ar isotopic analysis are listed in Table 1 and plottedagainst the cumulative released 39Ar fraction to establish the age

spectra (Fig. 7a). Data uncertainties in the figures and in the text aregiven as 2σ. The sericite concentrate from sample DA05-16 produceda plateau age of 107.2±0.6 Ma, which is consistent with its isochronage (106.3±5.4 Ma, Fig. 7b).

5.2. Major, trace element and Sr–Nd isotope data

The FM and GH have distinct major element compositions. Forexample, SiO2 contents of the FM range from 60.3 to 80.7 wt.% withMgO between 0.02 and 2.5 wt.% (samples with very high SiO2

contents show pervasive silica alteration). In contrast, rocks fromthe GH exhibit relative low SiO2 contents, from 47.5 to 58.5 wt.%, andsignificantly higherMgO contents from 1.9 to 7.0 wt.% (Table 3). In theTAS diagram (Fig. 8a), the FM rocks plot as andesite, dacite, trachyteand rhyolite, and show high-K calc-alkaline to shoshonitic character,whereas those from the GH plot in the basalt, basaltic andesite,andesite and trachyandesite fields, and show calc-alkaline to high Kcalc-alkaline character (Fig. 8b). All rocks from FM and GH aresubalkaline (Fig. 8a).

A clear differentiation trend between FM and GM is observed inthe SiO2 vs. major element variation diagrams. There is a negative

Fig. 9.Major oxides vs. SiO2 (wt.%) diagrams for the late Mesozoic volcanic rocks in the Lesser Hinggan Range. All major oxides are LOI-free, normalized to 100%. Symbols as in Fig. 8.

167Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

correlation between SiO2 and MgO, FeO* (total FeO=FeO+0.9Fe2O3), CaO, P2O5, TiO2, and a positive correlation between SiO2 andK2O. Alumina generally increases following the increase in SiO2 forGH, but decreases for FM samples (Fig. 9). There is a crude negativecorrelation between Na2O and SiO2 for FM samples but no suchcorrelation in the GH sample population (Fig. 9).

Except for one sample (b3064-2), all other rocks from the twoformations have similar chondrite-normalized rare earth element (REE)patterns, i.e., moderate light REE enrichment relative to heavy REE, with(La/Yb)n ratios of 5.4–12.8 (10.8 in average) and 2.3–15.6 (9.5 inaverage) for FM and GH, respectively (Table 4). The FM Samples displayslight to significant negative Eu anomalies (Eu*=0.12–0.92) whereasthe GH samples have only slight negative Eu anomalies (Eu*=0.73–

0.98). As a whole, Eu* displays a crude negative correlation with SiO2

(Fig. 10).In the primitivemantle-normalized trace element patterns (Fig. 11),

all samples display large iron lithophile element (LILE) and light earthelement (LREE) enrichment and significant negative Nb–Ta, P and Tianomalies and significant positiveU, Th and Pb anomalies. They are thuscompletely different fromMORB, OIB and CFB rocks, which show no orinsignificant HFSE anomalies (Smedley, 1986; Sun and McDonough,1989). Ba and Sr anomalies vary from one sample to another. Slightlypositive U anomalies are observed in all rocks.

Rocks from FM and GH exhibit distinct Sr and Nd isotopic composi-tions, although their trace element patterns are not distinct. The FM has anarrow age-corrected 87Sr/86Sr range of 0.707253–0.707373, and εNd(t)

Table 4Trace element contents (in ppm) of late Mesozoic volcanic rocks in the Lesser Hinggan Range, Heilongjiang province, NE China.

DA87-2-1 DA87-2 DA06-03 DA06-4 K48-2 b3064-2 b6074-4 b5009-1 b5039 b3113 b2054 b3005-1 b5035-2 b5138 b5124 b6108 b5140-1 b6069 b6082-1 b607 b3112 b6076 b6077

La 10.6 10.3 35.4 27.2 38.5 9.73 11.7 68.7 42.2 23.0 35.5 35.4 11.7 25.2 36.7 45.8 20.7 22.1 22.2 17.8 23.0 40.0 24.3Ce 23.6 22.8 67.6 53.3 70.0 20.7 21.9 93.9 77.8 43.0 66.9 71.1 28.1 51.8 72.3 83.0 42.0 43.1 44.0 33.8 43.0 75.0 44.7Pr 2.97 2.84 8.36 6.57 8.07 3.23 2.93 11.7 9.30 5.38 8.23 8.57 4.28 6.02 8.94 10.2 5.02 5.36 5.72 4.56 5.38 9.77 5.93Nd 10.1 9.77 31.8 24.9 29.1 13.2 10.5 45.1 34.3 21.2 30.5 32.5 20.3 23.8 35.3 38.3 20.0 21.8 23.3 19.0 21.2 38.5 23.3Sm 2.17 2.02 5.82 4.66 4.91 4.41 2.07 8.91 5.94 4.60 5.52 6.03 5.80 5.09 7.63 6.82 4.27 4.65 5.27 4.34 4.60 8.44 4.84Eu 0.26 0.25 1.33 1.10 1.23 0.18 0.09 1.98 1.43 1.31 1.34 1.43 1.75 1.40 1.81 1.75 1.26 1.39 1.51 1.35 1.31 1.88 1.40Gd 1.74 1.76 4.78 3.67 3.95 4.98 1.66 8.04 4.82 4.06 4.58 4.61 5.38 4.38 6.45 5.71 3.78 3.89 4.50 3.91 4.06 7.12 4.32Tb 0.28 0.27 0.62 0.50 0.52 1.19 0.25 1.27 0.63 0.62 0.63 0.62 1.01 0.67 0.99 0.72 0.58 0.61 0.67 0.61 0.62 1.08 0.67Dy 1.77 1.67 3.48 2.90 2.74 9.18 1.60 7.38 3.23 3.38 3.33 3.21 6.25 3.70 5.38 3.77 3.27 3.39 3.80 3.57 3.38 5.89 3.66Ho 0.35 0.34 0.65 0.58 0.52 1.98 0.29 1.51 0.62 0.63 0.63 0.58 1.27 0.69 1.00 0.70 0.61 0.64 0.72 0.65 0.63 1.09 0.69Er 1.23 1.14 2.08 1.84 1.66 6.52 0.99 4.72 1.92 1.83 1.98 1.77 3.80 2.03 2.88 2.17 1.77 1.83 2.04 1.96 1.83 3.16 2.06Tm 0.17 0.17 0.28 0.27 0.24 0.99 0.14 0.67 0.27 0.26 0.27 0.23 0.53 0.27 0.38 0.29 0.24 0.25 0.28 0.26 0.26 0.41 0.29Yb 1.28 1.26 1.97 1.86 1.66 6.84 1.01 4.49 1.88 1.60 1.89 1.58 3.48 1.78 2.42 1.93 1.57 1.59 1.72 1.62 1.60 2.62 1.83Lu 0.20 0.19 0.29 0.31 0.26 1.02 0.15 0.69 0.29 0.23 0.29 0.23 0.53 0.26 0.35 0.30 0.23 0.23 0.24 0.25 0.23 0.38 0.27Y 12.4 12.0 20.4 17.7 16.8 66.4 8.75 51.7 19.8 21.0 19.3 17.0 38.6 21.3 30.0 23.8 18.8 19.2 20.2 21.1 21.0 33.2 19.4Zr 70.7 79.4 263 266 229 150 120 153 239 191 247 216 208 249 340 249 209 203 198 163 191 350 200Hf 1.90 1.95 6.44 5.64 5.50 5.20 2.30 3.68 5.62 4.19 5.71 4.99 4.30 5.48 7.67 5.45 4.49 4.51 4.62 3.69 4.19 7.97 4.41Sc 2.05 2.03 9.40 11.2 6.52 2.49 1.68 10.6 9.06 18.6 10.2 13.0 39.4 16.9 12.6 8.74 17.9 19.7 16.4 22.0 18.6 12.9 20.2Cr 1.93 1.71 6.80 7.51 7.11 5.73 3.23 6.91 22.4 310 10.6 50.9 259 96.9 8.31 10.7 283 286 31.2 133 310 7.11 215Co 0.36 0.34 7.16 15.9 7.74 0.75 0.59 9.29 12.1 28.7 11.6 16.7 48.0 22.0 23.2 14.0 36.6 31.6 21.5 38.1 28.7 21.5 21.0Ni 0.69 0.65 4.37 6.86 6.11 1.26 2.59 6.74 12.8 148 8.22 21.5 30.0 53.9 47.0 11.1 208 181 45.0 75.6 148 44.9 85.1Cu 2.84 2.05 13.3 10.1 12.6 10.2 2.89 6.60 22.3 43.8 13.0 19.4 28.8 47.8 94.5 12.2 51.8 43.9 40.9 40.0 43.8 69.7 34.1Zn 4.73 4.73 64.3 103 72.7 25.2 98.4 50.7 77.5 86.1 73.5 95.5 108 71.6 81.9 87.5 74.5 78.8 78.2 80.3 86.1 84.9 74.4Ga 5.85 5.81 23.2 22.4 17.3 22.2 29.6 16.7 21.0 19.1 20.7 21.5 19.8 20.4 22.4 22.4 18.6 20.1 22.9 19.5 19.1 23.5 20.0Nb 9.53 9.63 9.60 10.2 10.5 12.6 29.9 6.49 11.6 12.4 9.89 8.19 8.37 11.7 21.7 10.7 10.3 13.8 10.9 8.35 12.4 23.2 11.5Ta 0.73 0.76 0.60 0.62 0.85 1.57 2.05 0.44 0.80 0.90 0.68 0.51 0.54 0.86 1.63 0.62 0.76 0.97 0.77 0.58 0.90 1.69 0.82Pb 14.8 14.7 6.61 8.35 18.8 20.3 17.4 36.8 18.7 11.9 17.4 21.7 7.24 14.4 20.4 15.1 12.8 11.1 11.9 8.05 11.9 19.3 12.0Th 8.51 8.64 6.36 7.56 10.5 29.4 19.3 6.56 11.5 6.42 8.65 6.67 1.00 7.20 11.9 9.77 6.01 6.13 5.47 3.55 6.42 12.0 5.82U 3.66 3.65 1.94 3.42 2.78 10.9 2.31 3.01 2.70 2.03 2.23 1.40 0.28 2.32 3.76 2.58 1.98 1.84 1.35 1.11 2.03 3.69 1.54Sr 35.0 36.0 31.0 202 264 51.0 12.0 325 567 345 582 606 296 362 300 712 327 413 494 418 345 290 382Rb 390 410 329 239 203 129 222 89.0 128 84.0 101 79.0 14.0 115 136 76.0 93.0 65.0 29.0 60.0 84.0 197 64.0V 5.00 b5.00 114 94.0 50.0 b5.00 5.00 85.0 75.0 125 93.0 110 227 135 148 97.0 114 132 135 150 125 156 137Ba 356 396 853 1289 1257 152 51.0 676 1111 451 1016 842 59.0 614 642 1257 471 423 548 397 451 647 553(La/Yb)n 5.43 5.55 12.50 8.98 15.16 0.98 7.99 10.19 14.90 10.24 12.53 15.76 2.26 9.92 10.74 15.63 9.21 9.84 9.47 7.29 10.24 10.78 9.21Eu* 0.40 0.40 0.76 0.79 0.83 0.12 0.14 0.71 0.80 0.92 0.80 0.80 0.95 0.89 0.78 0.84 0.95 0.98 0.93 0.99 0.92 0.73 0.93

168Z.Zhang

etal./

Ore

Geology

Reviews37

(2010)158

–174

Fig. 10. SiO2 (wt.%) vs. Eu* diagram for the late Mesozoic volcanic rocks in the LesserHinggan Range. Eu*=2EuN/(SmN+GdN). Symbols as in Fig. 8.

169Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

from−2.78 to−3.05 (t=108Ma), and exhibits much higher (87Sr/86Sr)and lower εNd(t) values in comparisonwith those from theGreatHingganRange (Fan et al., 2003), Heilongjiang province (Fig. 12). In contrast, theGHdisplays slightly a lower range in 87Sr/86Sr (0.705434 to 0.705763) andεNd(t) values from +0.76 to +1.83, which overlap those from the GreatHinggan Range (Fig. 12). By comparison, the 106 Ma-volcanic rocks in thewest Liaoning province, NE China, exhibit much higher εNd(t) values andlower (87Sr/86Sr)t (Yang and Li, 2008).

6. Discussion

6.1. Magma differentiation

Given the homogeneous Sr–Nd isotopic data (Table 5) andsystematic variations in major and trace elements (Figs. 9 and 11),crustal contamination played an insignificant role during magmaascent, although the Lesser Hinggan Range hosts a wide spectrum oflate Mesozoic volcanic rocks. Some correlation relationships observedon the Harker diagrams (Fig. 9), coupled with similar chondrite-normalized REE patterns and primitive mantle normalized traceelement patterns in the FM and GH suggest that crystal fractionationdid occur. Based on the petrographic observations and Harker plots(Fig. 9), it can be inferred that fractionation of clinopyroxene andplagioclase with minor olivine, orthopyroxene plus titanomagnetitehas occurred in the GH, whereas there is a fractionation of plagioclaseplus minor biotite, plus hornblende in the early stage and K-feldsparin the late stage in the FM. This interpretation is compatible with thepetrographic characteristics. However, the distinct Sr–Nd isotopiccompositions, and major and trace element compositions in bothformations suggest that they were not derived from a commonparental melt, but instead were derived from two distinct sourceregions. In other words, the rocks in the FM were not produced bycrystal fractionation of the magmas of GH.

The high SiO2 and low MgO contents of the late Mesozoic rocksindicate that these rocks are all differentiates. Sample b5035-2 has thelowest SiO2 contents (47 wt.%) and highest MgO (7 wt.%) and totalFeO, together with the lowest REE concentrations, possibly repre-senting the parental magmas from which the GH rocks were derived.However, this sample has low compatible element contents such asNi, Cr and Co, whereas sample b5140-1 has high MgO, Ni, Cr and Cocontents, but also high SiO2 contents (56 wt.%). Such Si- and Mg-richrocks are related to accumulation of orthopyroxene as indicated bythe presence of some orthopyroxene phenocrysts in the sample. Ingeneral, such Si- and Mg-rich rocks were interpreted to have beenformed from mantle-derived magmas by crustal contamination of a

high-Mg magma as invoked for siliceous high-Mg basalts (e.g., Arndtand Jenner, 1986; Cattell, 1987; Barnes, 1989; Skulski and Percival,1996). Sample b5035-2 could be attributed to removal of olivine fromparental magmas.

6.2. Source characteristics

The only practical approach to establish the source characteristicsbeneath the Lesser Hinggan Range is to invert basalt compositions.Ideally, we should use only near-primitive basalts but, as noted above,there are no such rocks (all samples have MgO contents ≤7.0 wt.%).Thus, we have to use the incompatible element ratios and isotopiccompositions to infer the mantle source because they are much lessaffected by crystal fractionation of parental magma.

The presence of negative Nb–Ta and Ti anomalies in the primitivemantle-normalized trace element patterns of the rocks from the GHcould be reached by the following processes: (1) partial melting of thesourceswithHFSE-richminerals (e.g., rutile and/or ilmenite) as residualphases; (2) crustal contamination during magma ascent; and (3)subduction-related metasomatism. If rutile was retained in the sourceduring partial melting, the parental melts derived from such mantlereservoirs should also have significantly negative Zr, Hf anomaliescoupled with Ti anomalies. However, such negative Zr or Hf anomalieshave not been observed in the primitive mantle-normalized patterns(Fig. 11) and it is therefore unlikely that there is residual rutile in themelt source. As mentioned above, insignificant crustal contaminationoccurred during magma ascent. Consequently, the observed Sr and Ndisotopic ratios were mainly inherited from the source of melting.

Previous investigations have suggested that multi-stage oceanicsubduction occurred in the late Paleozoic (e.g., Sëngor et al., 1993;Sëngor and Natal'in, 1996; Robinson et al., 1999; Zhao, 2009). Fluidsreleased from subducted oceanic crust and pelagic sediments aregenerally characterized by LILE and LREE enrichment relative to HFSE(e.g., Morris et al., 1990; Hawkesworth et al., 1993; MacDonald et al.,2000). These fluids metasomatize the overlying mantle peridotites,leading to LILE and LREE enrichment and HFSE depletion in themantle. Both studies of U–Th-series isotopes (Gill andWilliams, 1990;Elliott et al., 1997) and mineral–aqueous fluid partitioning experi-ments (Brenan et al., 1995; Keppler, 1996; Ayers, 1998) show that U ispreferentially transported, relative to Th, from the subducting slab tothe mantle wedge. Thus, the enrichment of U relative to Th on theprimitive mantle–normalized patterns during dehydration could beenvisioned. In summary, the geochemical variations of the GH can beinterpreted by oceanic plate subduction. However, oceanic platesubduction did not exist during the late Mesozoic (e.g., Engebretsonet al., 1985; Li and Yang, 1987; Zhao and Coe, 1996). Alternatively, theparental melts for the late Mesozoic volcanic rocks in the GH werederived from decompression melting of an enriched continentallithospheric mantle, which had been previously metasomatized byfluids derived from subducted slabs, during the closure of the paleo-Asian and/or Mongolia-Okhotsk Oceans. However, low (87Sr/86Sr)tand positive εNd(t) values suggest that depleted asthenosphericmantle had been involved in the sources of the GH rocks.

Several models have been proposed to interpret the petrogenesisof rhyolitic magmas in the Great Hinggan Range and adjacent areas:(1) remelting of continental crust (Zhao et al., 1989; Ge et al., 2000);(2) fractional crystallization of mantle-derived melts (e.g., Borg andClynne, 1998) or andesitic melts generated by partial melting ofhydrousmafic crust (Wang et al., 1985; Zhang and Bao, 1990); (3) 30%melting of tonalitic gneiss (Xu et al., 1994); and (4) mantle-derivedalkaline magmas contaminated by lower crustal materials (Jiang andQuan, 1988). However, the petrogenesis of the FM in the LesserHinggan Range has not been previously discussed.

As mentioned above, the distinct Sr and Nd isotopic compositionsbetween rhyolitic rocks in the FM and basaltic rocks in the GH suggestthat the rhyolitic magma could not be produced by fractional

Fig.

11.C

hond

rite-n

ormalized

REEpa

tterns

(left)

andprim

itiveman

tle-no

rmalized

traceelem

entpa

tterns

(right)of

thelate

Mesoz

oicvo

lcan

icrock

sin

theLe

sser

Hingg

anRa

nge.

Normalized

values

arefrom

Sunan

dMcD

onou

gh(1

989)

.

170 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

Fig. 12. (87Sr/86Sr)t vs. εNd(t) plots of the late Mesozoic volcanic rocks in the LesserHinggan Range. Mid-oceanic ridge basalt (MORB) and upper continental crust (UCC)are shown for comparison (Zindler and Hart, 1986; Taylor and McLennan, 1995). Thedata in western Liaoning and Great Hinggan Range are from Yang and Li (2008) and Fanet al. (2003), respectively.

171Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

crystallization of basaltic magmas of the GH. Furthermore, homoge-neous Sr and Nd isotopic compositions of the FM indicate no crustalcontamination during magma ascent. In addition to rhyolites,andesites and dacites, also occur in the FM, and all of these rocktypes have geochemical similarities, suggesting that rhyolitic magmasprobably represent the differentiation end-product of andesiticmagmas. In combination with their (87Sr/86Sr)t ( 0.7073) and εNd(t)values (∼ − 3), it can be inferred that the parental andesitic magmaswere generated by partial melting of lower mafic crust.

6.3. Timing of gold mineralization

The sericite sample yielded a good plateau age and appears to havebeen undisturbed because of its crystallization and cooling from initiallow hydrothermal temperatures. Thus, our study provides the first

Table 5Sr and Nd isotopic data of late Mesozoic volcanic rocks in the Lesser Hinggan Range, Heilon

Sample No. b5124 b6077 b6069

Group GH

Sm (ppm) 7.24 4.64 4.31Nd (ppm) 34.34 22.22 20.25Rb (ppm) 122.49 61.07 60.62Sr (ppm) 305.56 383.70 420.1787Rb/86Sr 1.1598 0.4604 0.4187Sr/86Sr 0.707374 0.706464 0.70147Sm/144Nd 0.1274 0.1261 0.12143Nd/144Nd 0.512682 0.5126261 0.51(87Sr/86Sr)t 0.705606 0.705763 0.70(143Nd/144Nd)t 0.512592 0.512537 0.51εNd(t) 1.83 0.76 1.40

108 Ma is used for age corrections.

precise age data on the Dong'an gold mineralization and supplementsthe radiometric data on the volcanic magmatism in the Lesser HingganRange. The 40Ar/39Ar plateau age for sericite fractions is 107.2±0.6 Ma,which postdates the rhyolite porphyry (108.1±2.4 Ma). As the sericitesamples were separated from the main ores, 107.2±0.6 Ma canrepresent the timing of gold mineralization.

Mao et al. (2003) proposed thatMesozoic ore deposits in the NorthChina craton and its adjacent areas, including the middle-lowerYangtze River Valley, occurred in three pulses at 190–160 Ma, ca.140 Ma, and 125–110 Ma. More recently, Mao et al. (2007) proposedthat epithermal gold systems in eastern China, which cover southChina, the eastern part of the North China craton and NE China,occurred at 175 Ma, whereas pulses at 105-94 Ma were onlyrecognized in south China (Huang et al., 1996; Li et al., 2001). In NEChina, two pulses of epithermal mineral systems, i.e., ca. 145 Ma(Tuanjiegou gold deposit in Heilongjiang province) and 122–127 Ma(Erdaogou in Liaoning province and Jinchanggouliang in InnerMongolia), have been previously recognized (Pang and Qiu, 1997;Mao et al., 2007), although a SHRIMP age of 111.5 Ma of zircon grainsfrom the granite in the Jinchang gold ore-field has been interpreted tobe a magmatic–hydrothermal event (Lu et al., 2009), and someyounger K–Ar ages (b120 Ma) were reported (Qi et al., 2005; Chenet al., 2007). Apart from the Dong'an gold deposit there is no other107 Ma-gold deposit in NE China, as far as we are aware, and thereforeit is likely that ca. 107 Ma could represent an important pulse of goldmineralization in the Lesser Hinggan Range, and possibly in NE China,because volcanic rocks dated at 106–108 Ma are common throughoutNE China (Fig. 1b). Furthermore, the discovery of the ca.107 MaDong'an gold deposit provides us with important implications forexploration targeting of epithermal gold deposits in Early Cretaceousfelsic rocks in the Lesser Hinggan range.

6.4. Tectonic, magmatic and mineralization events during late Mesozoic

Three major viewpoints have been proposed to interpret thetectonic setting of theMesozoic volcanic rocks in NE China: (1)mantleplume (e.g., Shao et al., 1994, 2001a,b; Deng et al., 1996; Lin et al.,1998; Ge et al., 1999); (2) subduction of the Mongol–Okhotsk Oceanand subsequent post-orogenic diffuse extension (Guo et al., 2001;Wang et al., 2002b; Fan et al., 2003; Meng, 2003); and; (3) subductionof the Paleo-Pacific plate beneath eastern China (Hilde et al., 1977;Jiang and Quan, 1988; Zhao et al., 1989;Wang et al., 2006; Zhang et al.,2008).

There are several lines of evidence to suggest that themantle plumemodel is unlikely. Firstly, the linear distributionof theMesozoic volcanicrocks along the whole NE China, and volcanismmigration fromwest toeast during the Late Mesozoic (Wang et al., 2006; Zhang et al., 2008),does not support this interpretation. Secondly, magmatic activitiesextended from 185 to 105 Ma (Zhang et al., 2008), i.e., much longer

gjiang province, NE China.

b5009-1 b3113 k48-2

FM

8.55 5.47 4.5345.20 31.07 27.1786.24 106.65 196.12

329.71 618.36 270.2674 0.7568 0.4990 2.10016070 0.708427 0.708134 0.71045485 0.1144 0.1065 0.10072661 0.512436 0.512421 0.5124135434 0.707274 0.707373 0.7072532570 0.512356 0.512346 0.512341

−2.78 −2.96 −3.05

Fig. 13. Sketch showing the spatial and temporal trends of peak magmatism in NE Asia, suggesting an eastwards migration from Great Hinggan Range to southwestern Japan(modified fromWang et al., 2006). Note age data around 106–108 Ma that had not been noted byWang et al. (2006) and may represent a previously unrecognised magmatic phasein NE China. The data in the Yanji and western Liaoning area are from Li et al. (2007) and Yang and Li (2008), respectively.

172 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

than the period normally associated with a mantle plume. Thirdly, thelack of updoming of lithosphere and high-temperature picrites isinconsistent with the plumemodel (Xu et al., 2004; Zhang et al., 2006).

Seismic tomography studies (Van der Voo et al., 1999) suggest thatthe Mongol–Okhotsk Ocean subducted northward beneath Siberia.Thus, the Mesozoic volcanic rocks in NE China could not have formedby subduction of the Mongol–Okhotsk Ocean. Alternatively, theMesozoic volcanic rocks in NE China and surrounding areas aredistributed in a NNE direction, parallel to the NNE-oriented Asiancontinental margin, suggesting that these volcanic rocks may berelated to subduction of the Paleo-Pacific plate.

Wang et al. (2006) proposed a delamination mechanism for thegeodynamic setting beneath northeast Asia in the Late Mesozoic. Thecollision between north China and Siberia obstructed the westwardsmovement of the lithosphere induced by the subduction of paleo-Pacific plate, causing a rise of strain in the lithosphere and finallyresulting in a shear-like lithospheric delamination starting from thewest of the Great Hinggan Range around 160 Ma, and then graduallyextending eastwards. This led to ashenospheric mantle upwelling andunderplating, resulting in magmatic activity in the western GreatHinggan Range in the Late Jurassic, and subsequently, in the LesserHinggan Range in the late stages of Early Cretaceous. Our new agedata are consistent with this viewpoint, i.e., eastward progressionof magmatism (Fig. 13). Asthenospheric upwelling resulted in partialmelting of mafic lower crust, producing the parental andesiticmagmas, which had experienced a different degree of fractionationto form the wide spectrum of rock types of the FM (andesitic, daciticand rhyolitic rocks). In contrast, the parental basaltic melts of the GHcould be attributed to partial melting of a mixture of an incompatibleelement-depleted anhydrous lherzolite asthenospheric mantle sourceand a hydrous less-enriched lithospheric mantle source.

Previouswork has shown that themineralogy, alteration, and two-phase (vapor and aqueous solutions) fluid inclusion characteristics ofthe Dong'an gold deposit (Yang, 2008) are similar to those of otheradularia–sericite-type or low-sulfidation epithermal systems (e.g.,Henley and Ellis, 1983; Heald et al., 1987; White and Hedenquist,1990; Hedenquist, 1996). Gold orebodies are, in general, spatiallyassociated with the rhyolite porphyries of the FM (Figs. 1c and 3),even if some gold orebodies are not immediately hosted by them, butoccupy fractured zones or faults which are not far from rhyolite

porphyries. Our new 40Ar/39Ar and SHRIMP U–Pb zircon age datafurther provide new evidence for a genetic link between rhyoliteporphyry and gold mineralization because of the nearly synchronousages within the error bars (108.1±2.4 and 107.2±0.6 Ma, respec-tively) The rhyolite porphyries are therefore inferred to have suppliedheat that drove the convective hydrothermal activity responsible forthe development of the Dong'an epithermal deposit, and alsoprovided magmatic fluid sources, as suggested by the H- and O-isotopic compositions of fluid inclusions (Yang, 2008).

7. Conclusions

1. A single sericite 40Ar/39Ar plateau age of 107.2±0.6 Ma for mainstage ore material represents the age of the mineralizing event atthe Dong'an adularia–sericite epithermal gold deposit. It is also theyoungest age of any gold deposit so far discovered in NE China. Itmay represent a previously unrecognized pulse of mineralizationin NE China.

2. The sericite age is concordant within error with SHRIMP U–Pbzircon age of 108.1±2.4 Ma for the rhyolitic porphyry that hoststhe gold ores. The new age data thus provide evidence for a geneticlink between rhyolitic porphyry and gold mineralization.

3. The rhyolitic magmas of the Fuminghe Formation, which aregenetically related to gold mineralization may represent the endproduct of differentiation of andesiticmagmas, whichwere derivedfrom the partial melting of mafic lower crust. In contrast, rocks ofthe overlying Ganhe Formation were produced by fractionation ofbasaltic magmas, derived from partial melting of a mixture of anincompatible element-depleted anhydrous lherzolite astheno-spheric mantle source and a hydrous lower enriched lithosphericmantle source in an extensional tectonic setting in response toupwelling of asthenospheric mantle.

Acknowledgements

We thankMr. Su Renkui and other colleagues for logistical supportduring field investigation in the Dong'an mine area. The authorswould like to thank Dr. B. Song for his assistance in performingSHRIMP analysis and Dr. Y. Wang for Ar–Ar dating. Constructivereviews and suggestions by Prof. Chen Y.J. and an anonymous

173Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

reviewer comments helped to improve our manuscript. Nigel Cook isthanked for his thoughtful, constructive comments and editorialsuggestions. The study was supported by the National Natural ScienceFoundation of China (Grant Nos. 40925006, 40772045), the NationalBasic Research Program of China (2009CB421002), 111 Project(B07011) and PCSIRT. Franco Pirajno publishes with the permissionof the Executive Director of the Geological Survey of WesternAustralia.

References

Arndt, N.T., Jenner, G.A., 1986. Crustally contaminated komatiites and basalts fromKambalda, Western Australia. Chemical Geology 56, 229–255.

Ayers, J., 1998. Trace element modeling of aqueous fluid–peridotite interaction in themantle wedge of subduction zones. Contributions toMineralogy and Petrology 132,390–404.

Barnes, S.J., 1989. Are Bushveld U-type parent magmas boninites or contaminatedkomatiites? Contributions to Mineralogy and Petrology 101, 447–457.

Black, L.P., Kamo, S.L., Allen, C.M., Aleinicoff, J.N., Davis, D.W., Korsch, R.J., Foudoulis, C.,2003. TEMORA I: a new zircon standard for Phanerozoic U–Pb geochronology.Chemical Geology 200, 155–170.

Borg, L.E., Clynne, M.A., 1998. The petrogenesis of felsic calc-alkaline magmas from thesouthernmost Cascades, California: origin by partial melting of basaltic lower crust.Journal of Petrology 39, 1197–1222.

Brenan, J.M., Shaw, H.F., Ryerson, F.J., Phinney, D.L., 1995. Mineral–aqueous fluidpartitioning of trace elements at 900° and 2.0 GPa: constraints on the trace elementchemistry of mantle and deep crustal fluids. Geochimica et Cosmochimica Acta 59,3331–3350.

Bureau of Geology and Mineral Resources of Nei Mongol Autonomous Region(BGMRNM), 1991. Regional Geology of Nei Mongol Autonomous Region. GeologicalPublishing House, Beijing. 725 pp. (in Chinese with English abstract).

Cattell, A., 1987. Enriched komatiitic basalts from Newton Township, Ontario: theirgenesis by crustal contamination of depleted komatiite magma. GeologicalMagazine 124, 303–309.

Chen, Y.J., Chen, H.Y., Zaw, K., Pirajno, F., Zhang, Z.J., 2007. Geodynamic settings andtectonic model of skarn gold deposits in China: an overview. Ore Geology Reviews31, 139–169.

Compston, W., Williams, I.S., Kirschvink, J.L., Zhang, Z., Ma, G., 1992. Zircon U–Pb agesfor the Early Cambrian time-scale. Journal of the Geological Society of London 149,171–184.

de Jong, K., Xiao, W.-J., Windley, B.F., Masago, H., Lo, C.-H., 2006. Ordovician 40Ar/39Arphengite ages from the blueschist-facies Ondor Sum subduction-accretion complex(Inner Mongolia) and implications for the early Paleozoic history of continentalblocks in China and adjacent areas. American Journal of Science 306, 799–845.

Deng, J.F., Zhao, H.L., Mo, X.X., Luo, Z.H., Du, S.Y., 1996. Continental root/plume structurein China-key to the continental geodynamics. Geological Publishing House, Beijing,pp. 1–110 (in Chinese).

Dulski, P., 1994. Interferences of oxide, hydroxide and chloride species in thedetermination of rare earth elements in geological samples by inductively coupledplasma-mass spectrometry. Fresenius's Journal of Analytical Chemistry 350,194–203.

Elliott, T., Plank, T., Zindler, A., White, W., Bourdon, B., 1997. Element transport fromslab to volcanic front at the Mariana arc. Journal of Geophysical Research 102,14991–15019.

Engebretson, D.C., Cox, A., Gordon, R.G., 1985. Relative motions between oceanic andcontinental plates in the Pacific basins. Geological Society of America SpecialPublication 206 59pp.

Fan, W.M., Guo, F., Wang, Y.J., Lin, G., 2003. Late Mesozoic calcalkaline volcanism ofpost-orogenic extension in the northern Da Hinggan Mountains, NortheasternChina. Journal of Volcanology and Geothermal Research 121, 115–135.

Ge, W.C., Lin, Q., Sun, D.Y., Wu, F.Y., Won, C.K., Lee, M.W., Jin, M.S., Yun, S.H., 1999.Geochemical characteristics of the Mesozoic basalts in Da Hinggan Ling: evidenceof themantlecrust interaction. Acta Petrologica Sinica 15, 397–407 (in Chinese withEnglish abstract).

Ge, W.C., Lin, Q., Sun, D.Y., Wu, F.Y., 2000. Geochemical study on of the two types ofMesozoic rhyolite lavas in the Da Hinggan Mts. Journal of China University ofGeosciences 25, 172–178 (in Chinese with English abstract).

Gill, J.B., Williams, R.W., 1990. Th isotope and U-series studies of subduction-relatedvolcanic rocks. Geochimica et Cosmochimica Acta 54, 1427–1442.

Guo, F., Fan, W.M., Wang, Y.J., Lin, G., 2001. Petrogenesis of the late Mesozoic bimodalvolcanic rocks in the southern Da Hinggan Mts., China:. Acta Petrologica Sinica 17,161–168 (in Chinese with English abstract).

Guo, J.H., Wang, C.S., Shi, Y.J., 2004. Geological and geochemical features of the Dong'angold deposit in Heilongjiang. Geology and Prospecting 40, 37–41.

Hames, W.E., Bowring, S.A., 1994. An empirical evaluation of the argon diffusiongeometry in muscovite. Earth and Planetary Science Letters 124, 161–169.

Han, Z.X., Hao, Z.P., Hou, M., 1995. Metallogenic series of ore deposits related toCaledonian granitoids in XiaoHingganling region. Mineral Deposits 14, 293–302 (inChinese with English abstract).

Harmer, R.H., Eglington, B.M., Farrow, D., Butcher, A.R., Auret, J.M., Stander, Y.Y.,Grosser, E., 1986. Manual of Laboratory Procedures for Isotope Analysis: NationalPhysical Research Laboratory. CSIR, Pretoria. 126 pp.

Hawkesworth, C.J., Gallagher, K., Hergt, J.M., McDermott, F., 1993. Mantle and slabcontributions in arc magmas. Annual Review of Earth and Planetary Sciences 21,175–204.

Hayba, D.O., Bethke, P.M., Heald, P., Foley, N.K., 1985. Geologic, mineralogic, andgeochemical characteristics of volcanic-hosted epithermal precious-metal depos-its. In: Berger, B.R. (Ed.), Geology and Geochemistry of Epithermal Systems:Reviews in Economic Geology, 2, pp. 129–167.

Heald, P., Foley, N.K., Hayba, D.O., 1987. Comparative anatomy of volcanic-hostedepithermal deposits — acid-sulfate and adularia–sericite types. Economic Geology82, 1–26.

Hedenquist, J.Q., 1996. Hydrothermal systems in volcanic arcs, origin of the explorationfor epithermal gold deposits, short course notes. Geological Survey of JapanMineralResource Department, Higashi 1-1-3, Tsukuba 305, Japan. 139 pp.

Heilongjiang Academy of Geological Exploration for Nonferrous Metals (HAGENM),2001. Exploration report for the Dong'an gold deposit in the Xunnke county,Heilongjiang Province. Unpublished report. (in Chinese).

Henley, R.W., Ellis, A.J., 1983. Geothermal systems ancient and modern: a geochemicalreview. Earth Science Reviews 19, 1–50.

Hilde, T.W.C., Uyeda, S., Kroenke, L., 1977. Evolution of the western Pacific and itsmargin. Tectonophysics 38, 145–165.

Huang, T.X., Liu, X.D., Zhang, J.C., 1996. The Bitian gold deposit: a quartz-adularia typeepithermal precious metal deposit. Geology and Geochemistry 6, 1–6 (in Chinesewith English abstract).

Irvine, T.N., Baragar, W.R.A., 1971. A guide to the chemical classification of the commonvolcanic rocks. Canadian Journal of Earth Sciences 8, 523–528.

Jiang, G.Y., Quan, H., 1988. Mesozoic volcanic rocks of Genhe and Hailar basins in DaHinggan Ling Range: Bulletin of Shenyang Institute Research. Chinese Academy ofGeological Sciences 17, 23–100 (in Chinese with English abstract).

Keppler, H., 1996. Constraints from partitioning experiments on the compositions ofsubduction-zone fluids. Nature 380, 237–240.

Lanphere, M.A., Baadsgaard, H., 1997. The Fish Canyon Tuff: a standard forgeochronology. AGU Abstracts with Program 78 (17), 326.

Le Bas, M., Le Maitre, R.W., Streckeisen, A., Zanettin, B., 1986. A chemical classification ofvolcanic rocks based on the total-silica diagram. Journal of Petrology 27, 745–750.

Li, S.T., Yang, S.G., 1987. The late Mesozoic rifting in the northeastern China and thefault-rifting basins in East Asia. Science in China (Series B) 21, 185–195.

Li, Z.N., Lin, B.Q., Zhang, Z.C., 2001. Magma-related gold deposits. In: Chen, Y.C., Li, Z.N.,Wu, R.S. (Eds.), Gold Deposits in China and Their Metallogenetic Regularities.Geological Publishing House, Beijing, pp. 102–181.

Li, C.W., Guo, F., Fan, W.M., Gao, X.F., 2007. Ar–Ar Geochronology of Late MesozoicVolcanic Rocks from the Yanji Area, NE China and Tectonic implications. Science inChina (Series D) 50, 505–518.

Lin, Q., Ge, W.C., Sun, D.Y., Wu, F.Y., Won, C.K., Min, K.D., Jin, M.S., Lee, M.W., Kwon, C.S.,Yun, S.H., 1998. Tectonic implications of Mesozoic volcanic rocks in NortheasternChina. Scientia Geologica Sinica 33, 129–139 (in Chinese with English abstract).

Lu, Y.H., Zhang, Y., Lai, Y., Wang, Y.Z., 2009. LA-ICPMS zircon U–Pb dating of magmatismand mineralization in the Jinchang gold ore-field, Heilongjiang Province. ActaPetrologica Sinica 25, 2902–2912 (in Chinese with English abstract).

Ludwig, K.R., 1998. Isoplot: A Plotting and Regression Program for Radiogenic IsotopeData, version 2.96.

Ma, L.F., Qiao, X.F., Fan, B.X., Min, R.R., Ding, X.Z., 2002. Atlas of Geology in China.Geological Publishing House, Beijing. 348 pp.

MacDonald, R., Hawkesworth, C.J., Heath, E., 2000. The Lesser Antilles volcanic chain: astudy in arc magmatism. Earth Science Reviews 49, 1–76.

Mao, J.W., Zhang, Z.H., Yu, J.J., Wang, Y.T., Niu, B.G., 2003. Geodynamic setting ofMesozoic large-scale mineralization in the North China and adjacent area:Implication from high precious and accurate ages of metal deposits. Science inChina (Series D) 33, 289–299.

Mao, J.W., Li, X.F., White, N.C., Zhao, C.S., Zhang, Z.H., Wang, Y.T., Hu, H.B., 2007. Types,characteristics, and geodynamic settings of Mesozoic epithermal gold deposits inEastern China. Resource Geology 57, 435–454.

Meng, Q.R., 2003. What drove late Mesozoic extension of the northern China–Mongoliatract? Tectonophysics 369, 155–174.

Morris, J.D., Leeman, W.P., Tera, F., 1990. The subducted component in island arc lavas:constraints from Be isotopes and B–Be systematics. Nature 344, 31–36.

Norrish, K., Chappell, B.W., 1977. X-ray fluorescence spectrometry, In: Zussman, J. (Ed.),Physical Methods in Determinative Mineralogy, 2nd edition. Academic Press, NewYork, pp. 201–272.

Pang, J.L., Qiu, Y.Z., 1997. 4 0Ar–39Ar age of sericite in Erdaogou deposit and its geologicalsignificance. Acta Mineralogica Sinica 17, 443–447 (in Chinese with Englishabstract).

Peccerillo, A., Taylor, S.R., 1976. Geochemistry of Eocene calc-alkaline volcanic rocksfrom the Kastamonon area, Northern Turkey. Contributions to Mineralogy andPetrology 58, 63–81.

Qi, J.P., Chen, Y.J., Pirajno, F., 2005. Geological characteristics and tectonic setting of theepithermal deposits in the northeast china. Journal of Mineralogy and Petrology 25,47–59 (in Chinese with English abstract).

Ren, J.S., Chen, T.Y., Niu, B.G., Liu, Z.G., Liu, F.R., 1990. Tectonic evolution of thecontinental lithosphere and metallogeny in eastern China and adjacent areas.Science Press, Beijing, pp. 1–25 (in Chinese).

Robinson, P.T., Zhou, M., Hu, X., 1999. Geochemical constraints on the origin of theHegenshan Ophiolite, Inner Mongolia, China. Journal of Asian Earth Sciences 17,423–442.

Sëngor, A.M.C., Natal'in, B.A., 1996. Paleotectonics in Asia: fragments of a synthesis. In:Yin, A., Harrison, M. (Eds.), The Tectonic Evolution of Asia. Cambridge UniversityPress, Cambridge, pp. 486–640.

174 Z. Zhang et al. / Ore Geology Reviews 37 (2010) 158–174

Sëngor, A.M.C., Natal'in, B.A., Burtman, V.S., 1993. Evolution of the Altaid tectoniccollage and Paleozoic crustal growth in Eurasia. Nature 364, 299–307.

Shao, J.A., Zang, S.X., Mou, B.L., 1994. Extensional tectonics and asthenosphericupwelling in the orogenic belt: a case study from Hinggan–Mongolia Orogenicbelt. Chinese Science Bulletin 39, 533–537.

Shao, J.A., Li, X.H., Zhang, L.Q., Mu, B.L., Liu, Y.L., 2001a. Geochemical conditions forgenetic mechanism of the Mesozoic bimodal dyke swarms in Nankou–Guyaju.Geochemica 30, 517–524 (in Chinese with English Abstract).

Shao, J.A., Liu, F.T., Chen, H., Han, Q.J., 2001b. Relationship betweenMesozoicmagmatism andsubduction in Da Hinggan-Yanshan area. Acta Geologica Sinica 75, 56–63.

Simmons, S.F., White, N.C., John, D.A., 2005. Geological characteristics of epithermalprecious and base metal deposits. Economic Geology 100th Anniversary volume,485-522.

Skulski, T., Percival, J.A., 1996. Allochthonous 2.78 Ga oceanic plateau slivers in a2.72 Ga continental arc sequence: Vizien greenstone belt, northeastern SuperiorProvince, Canada. Lithos 37, 163–179.

Smedley, P.L., 1986. The relationship between calc-alkaline volcanism and within-platecontinental rift volcanism: evidence from Scottish Palaeozoic lavas. Earth andPlanetary Science Letters 76, 113–128.

Song, B., Zhang, Y.H., Wan, Y.S., Jan, P., 2002. Mount making and procedure of theSHRIMP dating. Geological Review 48 (Suppl), 26–30 (in Chinese with Englishabstract).

Su, R.K., Yu, J.B., Chu, Y.J., Song, C.B., 2006. Geological characteristics and prospectingpotential of Dong An gold ore field in Heilongjiang. Gold Science and Technology14, 9–13 (in Chinese with English abstract).

Sun, S.S., McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts:implications for mantle composition and processes. In: Saunders, A.D., Norry, M.J.(Eds.), Magmatism in the Ocean Basins: Special Publication, 42. Geological Society,London, pp. 313–345.

Taylor, S.R., McLennan, S., 1995. The geochemical evolution of the continental crust.Reviews of Geophysics 33, 241–265.

Van der Voo, R., Spakman, W., Bijwaard, H., 1999. Mesozoic subducted slabs underSiberia. Nature 397, 246–249.

Wang, T.D., Zhang, X.Q., Xu, Y.S., 1985. Characteristics and genesis of the Mesozoicvolcanic rocks in the Zhaomeng district, Neimenggu. Acta Petrologica Sinica 1,74–87.

Wang, Y., Li, J.Y., Li, W.Q., 2002a. 40Ar/39Ar chronological evidence of dextral shear andtectonic evolution of the eastern Tianshan orogenic belt. Xingjiang Geology 20,315–319 (in Chinese with English abstract).

Wang, P.J., Liu, Z.J., Wang, S.X., Song, W.H., 2002b. 40Ar/39Ar and K/Ar dating of thevolcanic rocks in the Songliao basin, NE China: constraints on stratigraphy andbasin dynamics. International Journal of Earth Sciences 91, 331–340.

Wang, F., Zhou, X.H., Zhang, L.C., Ying, J.F., Zhang, Y.T., Wu, F.Y., Zhu, R.X., 2006. LateMesozoic volcanism in the Great Xing'an Range (NE China): timing andimplications for the dynamic setting of NE Asia. Earth and Planetary ScienceLetters 251, 179–198.

White, N.C., Hedenquist, J.W., 1990. Epithermal environments and styles of mineral-ization: variation and their causes, and guidelines for exploration. Journal ofGeochemical Exploration 36, 445–474.

Williams, I.S., 1998. U–Th–Pb geochronology by ion microprobe. In: McKibben, M.A.,Shanks, W.C., Ridley, W.I. (Eds.), Applications of Microanalytical Techniques toUnderstanding Mineralizing Processes: Reviews in Economic Geology, 7, pp. 1–35.

Wingate, M.T.D., Compston, W., 2000. Crystal orientation effects during ion microprobeU–Pb analysis of baddeleyite. Chemical Geology 168, 75–97.

Xiao, W.J., Windley, B.F., Hao, J., Zhai, M.-G., 2003. Accretion leading to collision and thePermian Solonker suture, Inner Mongolia, China. Termination of the central Asianorogenic belt. Tectonics 22, 1069, doi:10.1029/2002TC001484.

Xu, W.L., Sun, D.Y., Zhou, Y., 1994. Magmatism of Manzhouli-Suifenhe GeologicalSection and Structure of Crust. Geological Publishing House, Beijing. 94 pp (inChinese).

Xu, Y., He, B., Chung, S.L., Menzies, M.A., Frey, F.A., 2004. Geologic, geochemical, andgeophysical consequences of plume involvement in the Emeishan flood-basaltprovince. Geology 32, 917–920.

Yang, T.Z., 2008, Geology and Geochemistry of theMesozoic volcanic rocks and Dong'angold deposit in Heilongjiang province. Unpublished Master Degree Thesis, ChinaUniversity of Geosciences.

Yang, W., Li, S.G., 2008. Geochronology and geochemistry of the Mesozoic volcanicrocks in Western Liaoning: Implications for lithospheric thinning of the NorthChina Craton. Lithos 102, 88–117.

Yin, B.C., Ran, Q.C., 1997. Metallogenic evolution in Xiaohingganling- Zhangguangcail-ing region, Heilongjiang province. Mineral Deposits 16, 235–241 (in Chinese withEnglish abstract).

Zhang, D.Q., Bao, X.W., 1990. A study on the petrology, geochemistry and genesis of theBayannur intermediate-acidic volcano-plutonic complex in eastern innerMongolia. Geological Reviews 36, 289–297.

Zhang, Z.C., Mahoney, J.J., Mao, J.W., Wang, F.S., 2006. Geochemistry of picritic andassociated basalt flows of the western Emeishan flood basalt province, China.Journal of Petrology 47, 1997–2019.

Zhang, L.C., Zhou, X.H., Ying, J.F., Wang, F., Guo, F., Wan, B., Chen, Z.G., 2008.Geochemistry and Sr–Nd–Pb–Hf isotopes of Early Cretaceous basalts from theGreat Xinggan Range, NE China: Implications for their origin and mantle sourcecharacteristics. Chemical Geology 256, 12–23.

Zhao, D.P., 2009. Multiscale seismic tomography and mantle dynamics. GondwanaResearch 15, 297–323.

Zhao, X.X., Coe, R.S., 1996. Paleomagnetic constraints on the paleogeography of China:implications for Gondwanaland. Abstract, 30th International Geological Congress,Beijing, 1, p. 231.

Zhao, G.L., Yang, G.L., Fu, J.Y., Wang, Z., Fu, J.Y., Yang, Y.Z., 1989. Mesozoic volcanic rocksin central and southern Da Hinggan Ling Range. Beijing Science and TechnologyPublishing House, Beijing, pp. 1–260 (in Chinese with English abstract).

Zhou, T., Goldfarb, R.J., Phillips, G.N., 2002. Tectonics and distribution of gold deposits inChina: an overview. Mineralium Deposita 37, 249–282.

Zindler, A., Hart, S.R., 1986. Chemical dynamics. Annual Review of Earth and PlanetaryScience Letters 14, 493–571.