Tectonic Inversion

7/21/2019 Tectonic Inversion

1/18

Tectonic inversion in a segmented foreland basin from extensional to piggyback settings: The Tucumn basin in NW Argentina

Diego Nicolas Iaffa a , * , F. Sbat a, D. Bello b, O. Ferrer a, R. Mon c, A.A. Gutierrez ca GEOMODELS Research Institute, Department de Geodinmica i Geofsica, Facultat de Geologia, Universitat de Barcelona, C/Mart i Franqus s/n, 08028 Barcelona, Spainb Ecopetrol, D.C. Edi cio Principal Cr 13 No. 36 e 24, Bogot, Colombiac Dept. de Geologa, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumn, Miguel Lillo 205 4000 Tucumn, Argentina

a r t i c l e i n f o

Article history:Received 20 July 2010Accepted 14 February 2011

Keywords:Central AndesArgentinaCretaceous riftForeland basinTectonic inversionGrowth strata

a b s t r a c t

The Tucumn foreland basin is bounded by: 1) basement cored ranges with elevations over 6000 m inthe west; 2) inverted extensional grabens to the north; 3) basement thrust blocks in the south and4) basement cored small ranges in the east. This foreland basin is located between two geologicalprovinces: the Sierras Pampeanas and the Santa Brbara system.

Cretaceous Salta rifting extended southwards covering the entire eastern part of the province of Tucumn in NW Argentina. Syn-rift and post-rift deposits can be recognized in accordance with theirarchitectural geometries. Foreland basin sediments progressively covered the rift deposits as the Andeanorogen propagated towards the east.

Despite some early studies, the Tucumn basin is poorly documented. For the present study,44 sections of 2D seismic surveys amounting to more than 730 km were used to describe the structureand the depositional evolution of the basin. The present structure is the result of a long sequence of events that includes a compressional deformation during the Paleozoic, a rifting stage during theCretaceous and a foreland stage during the late Cenozoic. Although tectonic inversion, which has playeda role during the foreland stage since the Miocene, can be observed in many sectors of the basin, it is

more prominent along the margins. Reactivation of old basement discontinuities and inversion of Cretaceous normal faults produced the compartmentalization of the foreland, giving rise to the presentshape of the Tucumn basin. This evolution is recorded in the Neogene deposits.

2011 Elsevier Ltd. All rights reserved.

1. Introduction

The Tucumn Basin is located at the foot of the Andean Chain,between 26 and 28 south and 65 e 66 west ( Fig.1), and straddlesthe border of different geological provinces ( Ramos, 1999 ). Thebasin is bounded by the Sierra de Aconquija and the CumbresCalchaques to the west ( Fig. 2). These are the northern ranges of the Sierras Pampeanas, which are characterized by basementuplifted blocks that cut the Pampean at ( Allmendinger et al.,1983 ;Costa et al.,1999 ; Gonzlez Bonorino, 1950; Jordan et al., 1983 ). Thebasin is bounded by the Sierra de San Javier, Sierra de Medina andthe Sierra de Ramada to the north. These ranges form the southernunits of the Santa Brbara system due to tectonic inversion of Cretaceous extensional faults and to thrusting of syn-rift depositsover neogene layers ( Abascal, 2005; Kley and Monaldi, 2002; Kley

et al., 2005; Ramos, 1999 ). In the proximity of the Tucuman basintowards NNW is the southern tip of the Eastern Cordillera ( Carreraet al., 2006 ) (Fig. 1). To the east of the Tucumn basin lies theChacoparanaense plain ( Fig. 2), which has an average elevation of 200 m above sea level and is separated from the Tucumn Basin bythe Sierra de Guasayn. This N e S striking range attains a maximumelevation of 700 m ( Fig. 2), constitutes the eastern limit of theTucuman basin and acted as a structural high during Paleozoicorogenies ( Cristallini et al., 2004 ).

The Sierra de Aconquija and the Cumbres Calchaques, to thewest of the Tucuman basin, form an orographic barrier with peaksover 6000 m ( Fig. 2). The step between the Sierra de Aconquija andthe Tucumn plain reaches about 5000m. Further tothe west of theSierra de Aconquija and the Quilmes Range is the southern part of the Altiplano e Puna with a median altitude of 4000 m. This is thehighest plateau in the world in an active subduction margin(Allmendinger et al., 1997; Hindle et al., 2005; Isacks, 1988 ). Furtherto the south of the Sierra de Aconquija is the Sierra de Ambato,which constitutes the southwestern limit of the Tucumn Basin

* Corresponding author. Tel.: 34 934 035 914; fax: 34 934 021 340.E-mail address: [email protected] (D.N. Iaffa).

Contents lists available at ScienceDirect

Journal of South American Earth Sciences

j ou rna l homepage : www.e l sev i e r. com/ loca t e / j s ames

0895-9811/$ e see front matter 2011 Elsevier Ltd. All rights reserved.

doi: 10.1016/j.jsames.2011.02.009

Journal of South American Earth Sciences 31 (2011) 457 e 474
mailto:[email protected]://www.sciencedirect.com/science/journal/08959811http://www.elsevier.com/locate/jsameshttp://dx.doi.org/10.1016/j.jsames.2011.02.009http://dx.doi.org/10.1016/j.jsames.2011.02.009http://dx.doi.org/10.1016/j.jsames.2011.02.009http://dx.doi.org/10.1016/j.jsames.2011.02.009http://dx.doi.org/10.1016/j.jsames.2011.02.009http://dx.doi.org/10.1016/j.jsames.2011.02.009http://www.elsevier.com/locate/jsameshttp://www.sciencedirect.com/science/journal/08959811mailto:[email protected]


2/18

(Fig. 2). The NNW trending Ambato range is formed by a set of basement thrust blocks dipping to the east ( Cristallini et al., 2004;

Gutirrez and Mon, 2008; Roy et al., 2006 ).The structure of the Tucumn Basin has been studied bya number of authors. Cristallini et al. (2004) reprocessed andinterpreted several seismic sections from different surveys focusingon deep faults and detachments. Pacheco et al. (2000) presenteda sketch-map of the basin in time domains based on the interpre-tation of seismic sections. Other authors used different geophysicalmethods such as gravimetry ( Pomposiello et al., 1993 ) and mag-netotellury ( Favetto et al., 2007 ) to describe the shape and thedepth of the basin.

The aim of the present paper is twofold: 1) to describe theTucumn basin structures, including those resulting from tectonicinversion due to Cretaceous extension and Andean shortening, and2) to elucidate the role played by reactivation and inversion of

earlier faults in the basin evolution.

2. Geological setting

2.1. Stratigraphy

In this sector of the Andean chain, the basement is composed of Puncoviscana and Medina formations ( Bossi, 1969; Turner, 1959 )and granitoids of Precambrian to early Cambrian age ( Aceolazaet al., 2002 ) (Fig. 3). The two previous formations are made up of grayish colored metasediments, low to medium grade, bandedschists, which preserved the original lamination. Basement rocksare strongly foliated as a result of the dynamic metamorphismproducedduring the accretion of terranesin theEarly Paleozoic andsubsequent orogenies ( Ramos, 1988 ). Basement was subsequentlyintruded by Cambrian to Ordovician granitoids ( Battaglia, 1982;Gonzlez Bonorino, 1950; Mon and Hongn, 1991 ).

Eastwards of the Rosario Fault ( Fig. 2), thick series of Paleozoic

layers, belonging to the Chacoparanaense basin, have been

Fig.1. Location of the study area in the central Andes in Argentina, Chile and Boliviawith the political borders; the Tucumn province borders are in bold. Main geological provincesare displayed, modi ed from Ramos (1999) and Hilley and Coutand (2010) .

D.N. Iaffa et al. / Journal of South American Earth Sciences 31 (2011) 457 e 474458


3/18

described ( Fernndez Garrasino et al., 2005 ). They are made up of Silurian to Devonian clastic rocks ( Padula et al., 1967 ), depositedinitially in an extensional basin and then in a foreland setting

(Ramos, 1988 ). Although these layers have not been identi ed inthe Tucumn basin ( Cristallini et al., 2004 ) (Fig. 3) or to the west of the study area, small outcrops are present in the east of the Sierrade la Candelaria ( Fig. 2) (Mngano and Buatois, 2004 ).

Cretaceous to Paleogene sedimentary rocks unconformablyoverlie basement rocks and have interstrati ed alkaline volcanics(Galliski and Viramonte, 1988; Turner,1959 ). These layers form theSalta Group ( Fig. 3), which is attributed to the Salta rifting thatoccurred in an extensional back arc environment ( Kley andMonaldi, 2002; Turner, 1959 ). The basal unit of the Salta Group isthe Pirga subgroup, which consists of breccias, conglomerates,sandstones and red beds of continental environments such asalluvial fans, uvial plains and debris ows ( Gmez Omil et al.,1989; Moreno, 1970; Reyes and Sal ty, 1973; Sal ty and

Marquillas, 1981 ). The Pirga subgroup has been interpreted as

Cretaceous syn-rift deposits associated with extensional faults(Turner, 1959 ). The syn-tectonic character is evidenced by a fangeometry of layers onlapping the basement ( Carrera and Muoz,

2008; Comnguez and Ramos, 1995; Cristallini et al., 1997 ).Starved growing trenches began to be lled with breccias andconglomerates of basement clasts at the base of the sequence.Basaltic lavas and pyroclastic ows attributed to the extensionalstage are intercalated with the basal units ( Galliski and Viramonte,1988 ). Subsequently, these trenches were covered by decreasinggrain sequences of sandstones and shales ( Sal ty and Marquillas,1994 ). When the rifting episode ceased, syn-rift deposits werecovered by post-rift layers ( Sal ty and Marquillas, 1981; Turner,1959 ). These new sequences overlap the Pirga subgroup and thebasement ( Boll et al., 1989; Carrera et al., 2006; Cristallini et al.,1997 ). The Balbuena and Santa Brbara subgroups are made up of sandstones, limestones, evaporites and shales deposited in lacus-trine, shallow marine and continental settings ( Bonaparte et al.,

1977; Marquillas et al., 2003; Moreno, 1970 ). The Yacoraite

Fig. 2. Geological map of the study area with location of the seismic sections used in this study. Names of ranges and basins are abbreviated (from south to north): P.V. (PipanacoValley), A.B. (Ambato Block), S.Ac. (Sierra de Aconquija), C.A. (Campo Arenal), S.Q. (Sierra de Quilmes), S.M.B. (Santa Mara Basin), C.C. (Cumbres Calchaques), S.S.J. (Sierra de San Javier), S.L.R. (Sierra de La Ramada), S.M. (Sierra de Medina), S.d.C. (Sierra del Campo), Ch. B. (Choromoro Basin), S.L.C. (Sierra de La Candelaria), S.B. (Sierra del Brete) andAn.B. (Angastaco Basin).

D.N. Iaffa et al. / Journal of South American Earth Sciences 31 (2011) 457 e 474 459


4/18

formation, which is the upper part of the Balbuena subgroup, isformed by limestones and shales ( Marquillas and Sal ty,1994 ). Thisunit is the main oil source in other sub basins of the Salta Rift basinsuch as the Lomas de Olmedo sub-basin ( Boll et al., 1989; Turicet al., 1987 ). The Balbuena and Santa Barbara subgroups lleda sag basin resulting from thermal subsidence after the extension of the rifting episode ( Bianucci et al., 1981; Comnguez and Ramos,1995; Sal ty and Marquillas, 1994 ). The normal faults of the Saltarifting stage continued to be poorly active in the early stages of thedeposition of the Balbuena subgroup ( Bianucci et al., 1982; Kleyet al., 2005 ). The Balbuena subgroup is equivalent to the Rio Loroformation in the Choromoro Basin ( Abascal, 2005 ). Foreland sedi-ments were progressively covered by post-rift deposits. The tran-sition from post-rift to foreland settings occurred as the Andeandeformation started to propagate towards the east ( Carrera et al.,2006; Jordan and Alonso, 1987; Russo and Serraiotto, 1979 ). Theforeland basin stage can be recognized by the presence of anangular unconformity and a stratigraphic gap of the middle Eocene(Del Papa et al., 2010; Reynolds et al., 2000 ). Paleogene sandstonesand shales of the Aconquija formation crop out along the easternmargin of the Sierra de Aconquija ( Gonzlez Bonorino, 1950 )(Figs. 2 and 3 ). Paleogene sandstones are overlain by Ro Salsandstones and evaporites that are known as the Guasaynformation further to the east ( Battaglia, 1982 ). These layers area key level for correlation and are associated with the middleMiocene Paran Atlantic marine transgression ( Ramos and Alonso,1995; Uliana and Biddle, 1988 ). The transgressive event was evi-denced by gypsum rich sandstones between continental facies(Battaglia, 1982 ; Gavriloff and Bossi, 1992 ). These formations cropout along the periphery of the Tucumn basin in the southern partof the Sierra de Medina, on the western slope of the Sierra deGuasayn and on the eastern slope of the Sierra de Aconquija(Fig. 2). They are also present on the western side of the Sierra deAconquija and in the El Cajn and Santa Mara valleys ( Bossi et al.,2001 ; Gavriloff and Bossi, 1992 ; Kleinert and Strecker, 2001 ;Mortimer et al., 2007 ; Strecker et al., 1989 ).

The stratigraphic column of the Tucumn basin culminates inPliocene to Quaternary clastic continental synorogenic sequences(Ramos, 1999 ) that consist of the following formations: the IndiaMuerta, Acequiones and Ticucho. The India Muerta formation iscomposed of gray sandstones and shales of a uvial origin ( Bossiand Gavriloff, 1998 ). Overlying the India Muerta formation are theAcequiones and Ticucho formations that consist of coarser cong-lomerates, re ecting the diachronic uplifting of the surroundingranges ( Gonzlez, 2000 ). These units are grouped in the Las Caasformation in the Sierra de Gusayn and further to the east of theSierra ( Battaglia, 1982 ) (Fig. 2).

2.2. Regional structure

Tectonicinversion ofpreviousextensional faultsplaysa keyroleintheformation of the Eastern Cordillera ( Carrera et al., 2006 ; Coutandet al.,2001 ; Grier et al.,1991 ; Hongnet al., 2007; Kleyet al., 2005 )andtheSanta Brbara System ( Bianucci et al.,1982;Cristallini et al.,1997;Kley and Monaldi, 2002 ,) (Fig. 1).

However, the Sierras Pampeanas, which are composed of basement blocks bounded by high angle thrust faults ( Jordan et al.,1983 ), have a deep detachment that resulted from reactivation of old crustal discontinuities ( Allmendiger et al., 1983; GonzlezBonorino, 1950; Jordan et al., 1983 ). In the southern sector of theSierras Pampeanas, inverted extensional Cretaceous structureshave been documented ( Schmidt et al., 1995 ).

Thegeological provinceof theSanta Brbara system is formedbybasement cored ranges, with syn-rift and post-rift sedimentary

layers cropping out on their

anks ( Fig. 1) (Cristallini et al., 1997;

Grier et al., 1991; Kley and Monaldi, 2002 ). In the study area, theSierra deMedina,Sierrade laCandelaria,Sierrade laRamada andtheSierra delCampo form part of this geological province( Fig. 2). Theseranges wereupliftedby highangle thrust faults dueto reactivation of upper crustal discontinuities that originated in earlier tectoniccycles and to inversion of Cretaceous extensional faults ( Kley et al.,1999 ; Monaldi and Kley, 1997 ). The Sierra de Medina is boundedalong its southern margin by a thrust fault with a concave shape tothe north, which is very typical of a listric normal fault. This rangeshows syn-rift deposits of the Pirga subgroup thrusted over post-rift andforelandlayers ( Abascal,2005; Bossi,1969 ; Iaffa et al., 2008 ).The Sierrade la Ramadais an NNEtrendinganticline with basementrocks in the core, and is bounded by syn-rift deposits along bothmargins ( Fig. 2). This anticline was brought about by compression,inversion and folding of a Cretaceous extensional depocenter(Mngano and Buatois, 2004 ).

In the study area, the geological province of the Sierras Pam-peanas consists of the Cumbres Calchaques and the Sierra deQuilmes, Sierra de San Javier, Sierra de Aconquija, Sierra de Ambatoand the Sierra de Guasayn ( Fig. 2). These basement upthrustranges are the northernmost units of this large geological province(Allmendinger et al., 1983; Gonzlez Bonorino, 1950; Jordan et al.,1983 ). The Sierras Pampeanas cut the foreland plain and areextensive and have high altitudes ( Ramos, 1999 ). The Sierra de San Javier is a small NNE trending range, mainly formed by basementrocks ( Mon and Suayter, 1973 ). This range was uplifted by a thrustfault along the eastern margin and shows a normal series of theSalta group as far as the Neogene deposits in its western limb(Gonzlez, 2000 ). The Sierra de Aconquija and the Cumbres Cal-chaques are uplifted by an active double vergent system formed byhigh angle thrust faults ( Cristallini et al., 2004; Drozdzewski andMon, 1999 ). This type of structure has not reused pre-existingextensional faults, but has reactivated major crustal discontinuities,generating pop-up structures ( Sobel and Strecker, 2003 ). The tworanges show basement and a thin cover thrusted over the Cenozoicsedimentary layers ( Fig. 2). The Sierra de Aconquija and the Cum-

bres Calchaques are separated by the Amaicha northwest trendinglineament, which is probably due to a thrust fault that uplifted theCumbres Calchaques over the Sierra de Aconquija ( Allmendingeret al., 1983; De Urreiztieta et al., 1996 ). To the west of Sierra deAconquija is the Santa Mara basin, which is lled by Neogenesedimentary rocks ( Bossi et al., 1997 ). The uplift of the Sierra deAconquija, Cumbres Calchaques and the Sierra de Quilmes hasplayed a major role in the in lling of the basin ( Strecker et al.,1989 ).The uplifting of these ranges has been attributed to the early Plio-cene given the coarsening up in the sequence sediments and thepresence of gravel size deposits ( Bossi et al., 2001 ; Kleinert andStrecker, 2001 ). Using the apatite ssion-track methodology,Sobel and Strecker (2003) proposed that the uplifting of the Sierrade Aconquija and the Cumbres Calchaques started at 6 Ma and

continues to be active. Neotectonic activity occurred on both sidesof the range, the western ank being the more active one(Cristallini et al., 2004; Strecker et al., 1989 ). On this slope, Pleis-tocene rock avalanche deposits have been triggered by seismicitynear Campo Arenal ( Fauqu and Strecker, 1987 ) (Fig. 2).

The southeastorogenic front of the Sierra de Aconquija describesa regional rectilinear feature known as the Tucuman Lineament(Mon, 1976 ) or the Tucumn Transfer Zone ( De Urreiztieta et al.,1996 ). This feature has been interpreted as a dextral strike-slipfault by some authors ( De Urreiztieta et al., 1996; Roy et al., 2006 ).

Further south of the Sierra de Aconquija, the southwestern limitof the Tucumn basin is bounded by the Sierra de Ambato ( Fig. 2),a northwest trending range formed by a series of basement thrustblocks dipping to the east ( Cristallini et al., 2004; Roy et al., 2006 ;

Toselli et al., 1999 ).



5/18

The eastern limitof the Tucuman basin is the Sierrade Guasayn(Fig. 2), which is a small N e S range, with elevations lower than700 m and is uplifted by high angle thrust faults ( Cristallini et al.,2004 ). The Guasayn thrust fault places basement rocks overNeogene layers. According to Cristallini et al. (2004) , the MujerMuerta or the Tacanas high is the prolongation of the structureof the Sierra de Guasayn to the north ( Fig. 2). As the Sierra deGuasayn started to uplift probably in Pleistocene times, theTucumn basin evolved into a piggy back basin on top of the activeGuasayn thrust fault ( Cristallini et al., 2004; Drozdzewski andMon, 1999 ; Pacheco et al., 2000 ).

3. Basin description

3.1. Methodology

Forty-four 2D seismic sections amounting to more than 730 kmwere interpreted and their main re ectors were correlated. Theseseismic sections were originally acquired by the Argentine nationaloilcompany YPFbetween1989 and1991, thenprocessedas stackbutnot migrated. The geological interpretation of the sections wasperformed using Kingdom Suite software. These seismic sectionswere correlated in a 2D environment and the horizons were

matched. Eight horizons were correlated to reconstruct the geom-etry of the Tucumn basin. The vertical scale of the seismic sectionsis presented in timedomainsin two-waytime travel (secondsunits).The main horizons and structures are outlined in the seismicsections with the prominent seismostratigraphic units ( Figs. 3e 12).

Subsequently, the seismic interpretations were converted fromtime to depth domains. To this end, the velocity values obtained byCristallini et al. (2004) were used. These authors obtained seismicvelocities from a well drilled in the margin of the basin, Isca Yacux 1. The fact that there were no other wells in the basin obliged usto use data from other regions to compare and adjust the velocityvalues. The Metn sub-basin wells ( Cristallini et al., 1997 ) and theLomas de Olmedo sub-basin structural maps in depth domainswere used as constraints ( Disalvo et al., 2002; Masaferro et al.,2003 ). Thereafter, the basement horizon in depth domains wasused to construct a structural map.

3.2. Seismostratigraphic units

The lateral and vertical variations of the re ection patternsthroughout the seismic sections of the Tucumn basin enabled usto identify four superimposed re ective packages. The lowermostpackage one corresponds to the acoustic basement. It is composed

Fig. 3. Stratigraphic column and Seismostratigraphic units of the Tucumn basin.



6/18

of low intensity re ections with poor lateral continuity giving rise

to a homogeneous and chaotic seismic fcies. Associated strong anddipping re ections have been interpreted by Cristallini et al. (2004)as basement fabric discontinuities ( Fig. 4).

Overlying the basement, syn-rift deposits forming part of thePirgua subgroup can be identi ed by marked lateral thicknessvariations and fan geometries ( Fig. 5). The contact between thispackage and the acoustic basement top occurs through an onlaprelation. The syn-rift deposits are located in half-graben structures,increasing layer thickness towards the faults ( Fig. 5).

After the cessation of extension, the geometry of the rift basinchanged as the subsidence and the depositional rate diminished.Post-rift layers were set during thermal subsidence, when theactivity of normal faults became less intense and the post-rift basinacquired a sag geometry. The post-rift sequence shows good lateral

continuity and intensity in their seismic re ectiveness despite the

existence of some intercalated low amplitude re ectors. An initial

post-rift package onlaps the syn-rift sediments and the basement,and constitutes the Balbuena subgroup ( Fig. 3). An upper post-riftpackage, which corresponds to the Santa Brbara subgroup, isconcordantly located above the initial post-rift package in thecenter of the Tucumn basin but onlaps the basin borders ( Fig. 3).

Foreland deposits show more extensive and lateral continuoushorizons with high amplitudes. The lower contact is approximatelyparaconcordant over the post-rift facies. Three episodes may bedistinguished during this stage: Foreland basin I, Foreland basin IIand Foreland basin III. Foreland basin I is constituted by large,continuous re ective seams of different intensities associated withthe Andean uplifting that occurred at a considerable distance to thewest. This sequence coarsened up as the source area approachedthe depositional area. Intercalated in Foreland basin I are strong

re ective horizons, which are interpreted as marine deposits of the

Fig. 4. Seismic section 2542. Location in Fig. 2.



7/18

Atlantic transgressive event that covered the whole basin. Forelandbasin II is related to the start of the tectonic inversion of earlierextensional faults in the area and layers of this package were foldedand thrusted. Finally, Foreland basin III results from the mainuplifting of the surrounding ranges. During this stage, tectonicinversion controlled the depositional space and produces erosional

unconformities and growth strata.

3.3. Interpretation of seismic sections

Nine of the forty-four seismic sections of the different sectors of the Tucumn Basin will be discussed below in an attempt to char-acterize the shape, structure and evolution of the basin ( Fig. 2).

The most suitable section that illustrates the characteristics of

the seismostratigraphic units of the basin is seismic section 2542




8/18




9/18

(Fig. 4). This Ne S cross-section, which ends close to the town of Simoca, is parallel to the longest axis of the basin and shows thethickest package of syn-rift, post-rift and foreland deposits. Syn-riftdeposits were controlled by a large graben structure with a highangle normal fault and antithetic faults. Syn-rift layers grow inthickness against the southern fault and thin out to the north. Post-rift layers onlap syn-rift deposits and have lensoidal geometries,which enabled us to interpret a more subsident area in the centerof the basin during the deposition. At the base of the post-riftsequence are transparent bands that correspond to mud and salt.These transparent bands are covered by strong re ective seams in

the middle and upper parts of the top post-rift sequence. Forelandstage tabular packages were deposited over post-rift units and havea different re ectiveness with respect to the lower units. Forelandbasin I is represented by thick, mainly parallel and tabular units.Lateral continuity is less clear with respect to the post-rift stageexcept for a clear re ective seam located at 1.4 s. This seam could beinterpreted as marine deposits of the Paran transgressive event.Foreland basin II shows an increase in thickness of up to 0.8 s to thesouth. This could be dueto growing accommodational space causedby folding of the older units in a gentle anticline located in thenorthern part of the section. This folding is attributed to gentle




10/18

inversion of the northernmost extensional faults. The upper units,which cover the previous foreland stages, constitute Foreland basinIII. The geometry of these units suggests a break in the localuplifting.

The eastern margin of the Tucumn basin is exempli ed byseismic section 2523 ( Fig. 5), located northeast of Simoca ( Fig. 2). Inthis sector the basement shows strong re ective seams dipping tothe east. The contact between the basement top and the base of thesedimentary ll is located at 2 s in the east and 2.6 in the west. Syn-rift deposits can be recognized by their strong lateral thicknessvariations controlled by normal faults dipping to the west. At least3 half-graben structures are prominent, conditioned by high anglenormal faults. Hangingwall syn-rift layers increase in thicknessagainst the fault. The post-rift deposits are characterized by

re ective seams of good lateral continuity and a more intense

re ectiveness at the top. Post-rift deposits can be identi ed by theironlapping relation over the syn-rift deposits towards the east(Cristallini et al., 2004 ). The Santa Brbara layers increase inthickness westwards. The foreland deposits gently dip to the westin a paraconcordant relation over the post-rift deposits. The recentmost deposits of Foreland basin III can be recognized by their onlapto the east that is related to the tectonic uplifting of the east marginof the basin and by a greater thickness in the center of the basin tothe west.

Further north of seismic section 2523 and tothe east of the townof Tucumn ( Fig. 2) is seismic section 1559 ( Fig. 6). In this sector, thebasement top is closer to the surface and the entire sedimentarysequence is thinner. The basement is homogeneous without strongre ections, but chaotic and without continuous re ective seams.

The thickness of the syn-rift and post-rift deposits decreases with




11/18

respect to that of the center of the basin. The Pirga deposits aredif cult to be recognized in this section. Basal post-rift layers of theBalbuena subgroup are thinner but with a strongre ectiveness. TheSanta Brbara layers have a constant thickness. Nearly the wholesequence is folded in an anticline due to the inversion of the mainfault that controlled the syn-rift deposits and the formation of a footwall short cut. Small and gentle anticlines and synclines affectthe Balbuena deposits in the hangingwall of the main fault and areprobably due to the inversion of the antithetic faults. The depositsof Foreland basin III were sedimented synchronously with tectonicinversion as evidenced by growth strata.

Seismic section 1567 ( Fig. 7), which is in the northeast of thestudy area, has an E e W orientation and is located at the foot of the

Sierra de la Ramada ( Fig. 2). This seismic section shows a hanging-wall anticline that is associated with a high angle fault. A shortcutthrust is recognized in the footwall. An antithetic extensional faultdipping to the west was also inverted with minor displacements asdemonstrated by the gentle anticline present in the middle of a synclinorium. Tectonic inversion along this section was strongerthan in the previous sections. Inversion affected the sequence up tothe layers of Foreland basin I. These layers were folded and trun-cated by erosion before toplap sedimentation of the layers of Foreland basin II. The geometry of uppermost Pliocene to Quater-nary layers (Foreland basin II and III) reveal that tectonic inversionwas slightly reactivated during these periods. The inverted fault isa blind thrust that does not reach the surface.

The structure of the western margin of the Tucumn basin is

strongly in uenced by the uplifting of the Sierra de Aconquija and

the Sierra de Ambato. Seismic section 2503 ( Fig. 8) is oriented W e Ein the western half and NW e SE on its eastern side. This section islocated in the foothills of the Sierra de Aconquija and to the south of the town of Concepcin ( Fig. 2). This seismic section shows tiltedlayers dipping to the southeast, with an anticline syncline pair. Inthe northwest, three high angle faults can be identi ed. They wereextensional faults during rifting as evidenced by the greater syn-riftsediment thickness in the hangingwall than in the footwall. Two of these faults (between shot points 1100 and 900) have been invertedas shown by repetition and folding of the syn-rift, post-rift andForeland basin I layers. The fault located further west has not beeninverted and shows the original extensional geometry. To the east,an antithetic fault dipping to the northwest has not undergone

inversion. Pliocene to Holocene layers (Foreland basins II and III)show growth strata, indicating that the sedimentation of theselayers occurred during inversion and folding.

Seismic section 2501( Fig. 9) is located further south, close to thetownof VillaAlberdi. Themainfeaturein this section isa half-grabenstructure controlled by an extensional fault with a thick syn-riftpackage in the hanging wall. The extensional fault continued to beslightly active during the sedimentation of the lowest post-rift unit(the Balbuena subgroup). This fault, at its highest point, branchesinto twothrust faultsthat have an associated anticline involving thesequence up to the layers of Foreland basin II. The kinematicconnection of thethrust faultsand theextensional fault suggest thatthe latter has been slightly inverted. Towards the east, the layers of Foreland basin III onlap the limb of the anticline that was generated

by the tectonic inversion of the main fault.




12/18




13/18

In the southern sector of the Tucumn basin, seismic sectionsare more spaced. Seismic section 2570 ( Fig. 10) is located in thesouthernpartof the basin, with an NNW e SSE orientation. This longseismic section describes a series of half-graben structurescontrolled by extensional faults dipping to the south. Syn-riftdeposits increase in thickness towards the southern extensionaldepocenters. The post-rift and foreland layers are tiltedand grow inthickness to the north, i.e. towardsthe centerof the Tucumn basin.Foreland sequences are thinner than in the previous seismicsections. Folding affected the whole stratigraphic sequence. Small

asymmetric anticlines with a southern limb with a greater dip are

located over the main extensional faults in the southern part(Fig. 10 ). Their origin will be discussed below.

To the east and south, close to the Sierra de Guasayn and to thesouth of the Ro Hondo dam is seismic section 2491 ( Fig. 11 ). Thisseismic section is located in the southeastern margin of the basin.The basement shows a series of strong re ective seams dipping tothe east. Almost no syn-rift and few post-rift layers were identi edin this section. The upper post-rift units (Santa Brbara subgroup)thicken to the west as do the foreland layers. An anticline can beobserved in the middle of the section associated with a high angle

blind thrust. This basement thrust fault constitutes a backthrust of




14/18

the Sierra de Guasayn ( Fig. 2) and does not control the thickness of the syn-rift layers. The anticline involves the whole sedimentarysequence as far as the layers of Foreland basin II. Moreover, its westlimb is onlapped by the layers of Foreland basin III.

The eastern border of the Tucumn basin is bounded by a highangle thrust fault that is controlled by a deep detachment. Seismicsection 2467 ( Fig. 12 ) crosses an area that underwent no exten-sional activity during the Cretaceous as evidenced by the uniformthickness of the syn-rift deposits. These deposits are much thinnerthan in other sections and represent distal positions with respect tothe extensional depocenter. The layers of Foreland basin I increaseslightly in thickness towards the east. Between shot points 700 and500 is a pop-up that corresponds to the Mujer Muerta high. Thewestern thrust fault of this structure produced a fault propagationfold, which folded the stratigraphic sequence as far as the layers of Foreland basin II. The layers of Foreland basin III onlap the afore-mentioned fault propagation fold. This structure is similar to theone described to the south in seismic section 2491 ( Fig. 11 ). The

eastern thrust fault of the pop-up produces a small displacement in

the whole stratigraphic sequence and reaches the surface. The twothrust faults that bound the Mujer Muerta High are active. Close tothe eastern end of the section are two conjugate normal faults witha small displacement and associated folds.

4. Structural analysis of the Tucumn basin

The basin has a triangular shape inplanview, the eastern limit isNe S, the northwestern limit is NE e SW and the southwestern limitis NNW e SSE (Fig. 13). The basin is asymmetric with a steeperwestern margin and a gentler eastern slope ( Porto et al.,1982 ). Thenorthern sector of the basin is shallower and narrower than thesouthern sector. The geometry of the basin was controlled byextensional faulting and was subsequently shaped by tectonicinversion and thrusting. The main depocenter of the basin wastermed the Leales depocenter by Pacheco et al. (2000) and coin-cides with a Cretaceous graben ( Fig. 4) striking NE e SW (Fig.13 ). Tothe north, and separated by a small structural high is another small

depocenter with syn-rift deposits ( Fig. 13), which may be termed




15/18

the Famaill depocenter because of its proximity to this town(Fig. 2).

Cretaceous extensional structures were also described in otherparts of the Tucumn basin. The Villa Alberdi e Concepcin graben(Pomposiello et al., 1993 ) (Figs. 2, 8 and 9 and 13 ) was controlled bya northeast dipping fault in the north and a southwest dipping faultin the south. Another large accumulation of syn-rift deposits islocated to the northeast of the basin ( Figs. 2, 6, 7 and 13 ) in a grabenthatcould be the subsurface continuation of the inverted graben thatcrops out in the Sierra de La Ramada or in the Sierra de Medina. To

the south, a number of half-grabens were identi ed ( Figs. 2 and 10 ).

The grabens and their normal faults must be oriented E e W sincethey are not recognized in the orthogonalseismic sections to the east(Fig. 11 ) and to the west.

Folding of the sedimentary cover occurred as a result of differentmechanisms. Some folds have roll-over geometries and are locatedin the hangingwall of Cretaceous extensional faults ( Figs. 5 and 9 ).Other hangingwall anticlines are fault propagation folds producedby inversion of Cretaceous extensional faults ( Figs. 6, 7 and 8 ) or byhigh angle thrust faults ( Figs. 11 and 12 ). By contrast, some anti-clines are located over the extensional faults ( Fig. 10) and may

be due to one of three mechanisms: a) tectonic inversion,

Fig. 13. Structural map of the basement top in depth domains and of interpreted subsurface structures. Gray lines correspond to seismic pro les. Basement and Cretaceous syn-rift(Pirgua subgroup) outcrops, and regional faults visible in the surface are also represented.



16/18

b) extensional reactivation or c) differential subsidence due tolateral change in thickness of the syn-rift layers and to their unevencompactation below the load of the sedimentary column ( Cristalliniet al., 2006 ). The last mechanism is the most probable owing to theposition of the syncline trough over the maximun syn-rift thickness.Differential subsidence is responsible for folding the post-rift andthe foreland layers over the syn-rift depositsand the rigid basement(Cristallini et al., 2006 ).

5. Discussion

Thestudyarea hasundergone a numberof stagesof deformationwithin different tectonic settings. The absence of Paleozoic rocks inthe basin suggests that the area was a structural high during thisperiod. In Cretaceous times, the Salta rifting produced half grabensand a sedimentary in ll related sequence ( Porto et al.,1982; Sal tyand Marquillas, 1981 ). The syn-rift Pirga subgroup increases inthickness towards the Cretaceous extensional faults and thins outfrom these faults. The layers of the Pirga subgroup onlap thestructural highs but become progressively thinner towards themargins of the basin, petering out to the southeast ( Fig. 11 ).

The post-rift sag phase, which is due to the cooling of thethermal anomaly associated with the Salta rifting, created accom-modational space by slowsubsidence. Post-rift deposits of the Saltagroup are thinner towards the basin margins where the basementtop is closer to the surface. The maximum thickness of the post-riftdeposits coincides with the syn-rift depocenters in the centerof thebasin ( Fig. 4).The onlap of the post-rift deposits on the syn-riftdeposits provides evidence of the arenal growth of the post-riftbasin and of the location of areas of greater subsidence ( Figs. 4,5 and 10 ). A foreland basin developed over the post-rift basin ina paraconcordant stratigraphic relationship. A hiatus in the strati-graphic sequence has been reported ( Reynolds et al., 2000; DelPapa et al., 2010 ). The subsidence mechanisms changed in theforeland basin stage. Sedimentation space increased owing to thetectonic load as the orogen grew in the west ( Carrapa et al., 2006;

Carrapa and DeCelles, 2008; Jordan et al., 1983; Jordan and Alonso,1987 ). The foreland basin associated with the Andean orogenystarted as a regional single unit and then compartmentalized intosub-basins coeval with the uplifting of the Pampean Ranges and theSanta Brbara system ( Carrapa et al., 2005; Coughlin et al., 1998 ).The deposits of Foreland basin I are tabular layers covering thepost-rift units ( Fig. 4). This sequence, which is termed Forelandbasin I, was identi ed by the onlap of these layers on the basinmargins. Foreland basin I started to develop during the earlyuplifting of the eastern margin of the Puna plateau in the middleEocene ( Carrapa et al., 2005; Isacks, 1988; Jordan and Alonso,1987 ).Foreland basin II resulted from the uplifting of the surroundingranges, and is associated with growth strata geometries ( Figs. 7and 8 ). During this stage, the foreland basin started to be frag-

mented into different sub-basins. Subsidence became local withranges uplifting and controlling the sedimentary supply. Short-ening produced tectonic inversion of the Cretaceous extensionalfaults, folding the sedimentary cover. As pointed out by Cristalliniet al. (2004) , during sedimentation of the layers of Foreland basinIII, the Tucumn basin was separated from the rest of the forelandbasin by uplifting of the Sierra de Guasayn and the India MuertaHigh, which has caused the Tucumn basin to evolve into a piggyback basin. The western margin uplift generates more subsidencethrough tectonic load ( Fig. 8).

According to the age of growth strata, some structures can beconsidered as active or potentially active whereas others cannot.Neotectonic activity has been recorded along both margins of theSierra de Aconquija ( Cristallini et al., 2004; Drozdzewski and Mon,

1999 ). Active seismicity has been documented together with surface

evidence of earthquakes and rock avalanches on the western slope(Fauquand Strecker,1987 ). Inseismic section 2503( Fig. 8), thewholesequence is involved in a thrust fault related fold. Growth strataprovide evidence of folding during sedimentation of the layers of Foreland basins II andIII.Giventhat the Sierrade Aconquija started touplift6 Maago ( Sobel and Strecker, 2003 ), this age could be assignedto the basal layers of Foreland basin II. Seismic section 2501 ( Fig. 9)also shows growth strata in the layers of Foreland basin III but, in thiscase, onlap is in the opposite sense in seismic section 2503 ( Fig. 8).

The Sierra de Guasayn and the Mujer Muerta High are a pop-upuplifted by a double vergent high angle thrust fault system ( Figs. 11and 12 ), which is similar to the Sierra de Aconquija and the Cum-bres Calchaques ( Drozdzewski and Mon,1999 ). The double vergentstructure visible in seismic section 2467 ( Fig. 12) folded the wholestratigraphic sequence with topographic and subsurface evidenceof recent uplifting.

The Sierra de Medina provides surface evidence of recentinversion of a Cretaceous extensional fault as a thrust fault thatelevates the range in its southern margin ( Fig. 2). Nearby, seismicsections show different geometries such as in seismic section 1567(Fig. 7), which has an erosion surface that affects the layers of Foreland basin I. This inversion structure ceased to uplift before thesedimentation of Foreland basin II. A slight increase in layerthickness in the west and folding of the layers of Foreland basins IIand III suggest that the inverted fault could have been reactivatedrecently. Moreover, in seismic section 1559 ( Fig. 6), growth stratafurnish evidence that the inverted fault continues to be active.

In the center of the Tucumn Basin, tectonic inversion is not asclear as along the margins. In seismic section 2542 ( Fig. 4), thelayers of Foreland basin III cover the whole sequence and presentno folding nor growth strata. This indicates that these faults haveceased to be active.

Strike-slip effects are not easy to identify using 2D seismicsections. De Urreiztieta et al. (1996) described a dextral fault slip of the Tucumn transfer zone, but strike-slip structures such astransgressive or transtensive structures have not been documented

(Cristallini et al., 2004 ).The depth of the Tucumn basin cannot be constrained because

of the lack of wells across the entire column. The maximum depthof the basement top is located in the middle of seismic section 2542(Fig. 4) and is about 3.4 s in TWT. The velocity values of Cristalliniet al. (2004) were used to perform a time to depth conversion.Our results reveal that the basin should be about 7000 m deep.These values are comparatively higher than other estimations.Pomposiello et al. (2002) using gravimetry and Favetto et al. (2007)using magnetothelluric obtained depths of 4000 e 5000 m in thecentral part of the basin. The results from neighbouring basins of the Salta rift such as the Choromoro Basin gave a depth of 3000 m(Abascal, 2005 ).

6. Conclusions

Basement, syn-rift, post-rift and foreland strata may be inter-preted and differentiated in the seismic sections in accordance withthe geometry of their horizons. The basement discontinuities con-ditioned the structural style and exerted a strong in uence on theselective orientation of Cretaceous extensional faults and on that of blocks uplifted in Neogene times. Inversion of the Cretaceousextensional faults occurredalong the northernand western marginsof the Tucumn basin. In the eastern margin it is not easy to detecttectonic inversion despite the fact that it could be interpreted thatsmall extensional steps are slightly inverted. The southern part of the basinpreserved the Cretaceous extensional geometries withoutbeing inverted. Inversion is clear along the southwestern and

northwestern margins of the Tucumn basin. Moreover, inversion



17/18

structures are clearly observed at the surface to the north of theTucuman basin, i.e. in the Medina Range syn-rift deposits are thrustover post-rift and foreland layers.

Folding was produced by reactivation of basement discontinu-ities by means of high angle thrust faults, inversion of earlierextensional faults and by differential subsidence owing to thestratigraphic column load on syn-rift sediments that varied later-ally in thickness. Double vergent high angle thrust faults in theeastern margin of the basin continued to uplift the Guasayn Rangeand the Mujer Muerta High, evolving into a pop-up and initiatingthe transformation of the Tucuman basin into a piggy back basin.The growth of pop-ups in the foreland is a long term process thatproduces the compartmentalization of an early continuous forelandbasin.

Growth strata associated with uplifting of the nearby rangesandwith blind thrusts were identi ed in many sectors of the basin.These features were crucial in identifying the evolution of the basinsedimentary in ll and the age and mechanisms of range uplift.

Acknowledgements

This research is supported by the following projects: 2005-00397SGRfrom the Generalitatde Catalunya and Consolider-Ingenio2010 program (CSD2006-004 Topo-Iberia ) and CGL2007-66431-C02-01/BTE (Modelizacin Estructural 4D) from the Ministerio deEducacin y Ciencia of the Spanish government. The rst authorwas funded by the AlBan scholarships program. We would like tothank Yanina Basile and Tomas Zapata from Repsol-YPF as well asErnesto Cristallini of Universidad de Buenos Aires for facilitatingthe seismic information, Mireia Butille and Joana Mencos from theUniversity of Barcelona for their help in software applications andGeorge von Knorring for reviewing the English of this paper. Weare indebted to Fernando Hong and to an anonymous reviewer fortheir helpful comments on an earlier version that greatly improvedthis manuscript.

The seismic interpretation used The Kingdom Company soft-ware, which was generously provided by Seismic Micro-Technologyvia the University Gift Program.

References

Abascal, L., del, V., 2005. Combined thin-skinned and thick-skinned deformation inthe central Andean foreland of northwestern Argentina. Journal of SouthAmerican Earth Sciences 19, 75 e 81.

Aceolaza, F.G., Miller, H., Toselli, A.J., 2002. Proterozoic e Early Paleozoic evolutionin western South America. A discussion. Tectonophysics 354, 121 e 137.

Allmendinger, R.W., Ramos, V.A., Jordan, T.E., Palma, M., Isacks, B.L., 1983.Paleogeography and Andean structural geometry, northwest Argentina.Tectonics 2, 1 e 16.

Allmendinger, R.W., Isacks, B.L., Jordan, T.E., Kay, S.M., 1997. The evolution of theAltiplano e Puna plateau of the Central Andes. Annual Reviews of Earth andPlanetary Sciences 25, 139 e 174.

Battaglia, A.C., 1982. Descripcin geolgica de las Hojas 13f, Ro Hondo, 13g, San-tiago del Estero, 14g, El Alto, 14h, Villa San Martn, 15g, Fras. Provincias deSantiago del Estero, Catamarca y Tucumn. Servicio Geolgico Nacional, BuenosAires, Argentina 569 (186), 80.

Bianucci, H.A., Acevedo, O.M., Cerdn, J.J., 1981. Evolucin tectosedimentaria delGrupo Salta en la subcuenca Lomas de Olmedo (Provincias de Salta y Formosa):VIII Congreso Geolgico Argentino (San Luis). Actas 3, 159 e 172.

Bianucci, H., Momovc, J.F., Acevedo, O.M., 1982. Inversion Tectnica y Plegamientosresultantes en la Comarca puesto Guardian-Dos Puntitas. Depto. Orn, Provinciade Salta. Primer Congreso Nacional de Hidrocarburos, Buenos Aires. 23 e 30.

Boll, A., Gmez Omil, R.J., Hernndez, R.M., 1989. Sntesis estratigr ca del GrupoSalta. Gerencia general de Exploracin Y.P.F. (inedit).

Bonaparte, J., Sal ty, J., Bossi, G., Powell, J., 1977. Hallazgo de dinosaurios y avescretcicas en la Formacin Lecho de El Brete (Salta), prximo al lmite conTucumn. Acta Geolgica Lilloana 14, 5 e 17.

Bossi, G.E., 1969. Geologa y estratigrafa del sector sur del Valle de Choromoro. ActaGeolgica Lilloana 10, 17 e 64.

Bossi, G.E., Gavriloff, I.J., 1998. Terciario. Estratigrafa, Bioestratigrafa y Paleo-

geografa. In: Gianfrancisco, M., Puchulu, M.E., Durango de Cabrera, J.,

Aceolaza, G.F. (Eds.), Geologa de Tucumn (2 a ed.), Publicacin Especial,Colegio de Graduados en Ciencias Geolgicas de Tucumn, pp. 87 e 109.

Bossi, G.E., Muruaga, C., Georgieff, S., Ahumada, A.L., Ibaez, L., Vides, M.E., 1997. TheSanta Mara-Hualfn Neogene Basin of the Pampean Ranges: an example of mixed tectonic evolution. 1 Congreso Latinoamericano de Sedimentologa I,97 e 104.

Bossi, G.E., Georgieff, S., Gavriloff, I., Ibez, L., Muruaga, C., 2001. Cenozoic evolu-tion of the intramontane Santa Mara basin, Pampean ranges, northwesternArgentina. Journal of South American Earth Sciences 14, 725 e 734.

Carrapa, B., Adelmann, D., Hilley, G., Mortimer, E., Strecker, M.R., Sobel, E.R., 2005.

Oligocene uplift, establishment of internal drainage and development of plateau morphology in the southern Central Andes. Tectonics 24, TC4011.

Carrapa, B., DeCelles, P.G., 2008. Eocene exhumation and basin development in thePuna of northwestern Argentina. Tectonics 27, TC1015.

Carrapa, B., Sobel, E., Strecker, M.R., 2006. Cenozoic orogenic growth in the CentralAndes: evidence from rock provenance and apatite ssion track thermochro-nology along the southernmost Puna Plateau margin (NWArgentina). Earth andPlanetary Science Letters 247, 82 e 100.

Carrera, N., Muoz, J.A., Sbat, F., Mon, R., Roca, E., 2006. The role of inversiontectonics in the structure of the Cordillera oriental (NW Argentinean Andes). Journal of Structural Geology 28, 1921 e 1932.

Carrera, N., Muoz, J.A., 2008. Thrusting evolution in the southern CordilleraOriental (Northern Argentine Andes): constraints from growth strata. Tecto-nophysics 459, 107 e 122.

Comnguez, A.H., Ramos, V.A., 1995. Geometry and seismic expresin of theCretaceous Salta rift of northwestern Argentina. In: Tankard, A.J., Suarez, R.,Welsink, H.J. (Eds.), Petroleum Basins of South America. Memoir, vol. 62.American Association of Petroleum Geologists, pp. 325 e 340.

Costa, C.H., Giaccardi, A.D., Gonzalez Daz, E.F., 1999. Palaeolandsurfaces and neo-tectonic analysis in the southern Sierras Pampeanas, Argentina. In: Smith, B.J.,Whalley, W.B., Warke, P.A. (Eds.), En: uplift, erosion and stability; perspectiveson longterm landscape development. Geological Society Special Publications,162, pp. 229 e 238.

Coughlin, T.J., O Sullivan, P.B., Kohn, B.P., Holcombe, R.J., 1998. Apatite ssion-trackthermochronology of the Sierras Pampeanas, central western Argentina;implications for the mechanism of plateau uplift in the Andes. Geology 26 (11),999 e 1002.

Coutand, I., Cobbold, P.R., de Urreiztieta, M.de, Gautier, P., Chauvin., A., Gapais, D.,Rossello, E.A., Lopez Gamundi, ., O., 2001. Style and history of the Andeandeformation, Puna Plateau, northwestern Argentina. Tectonics 20, 210 e 234.

Cristallini, E., Bottesi, G., Gavarrino, A., Rodrguez, L., Yomezzoli, R., Cameron, R.,2006. Syn-rift geometry of the Neuqun basin in northeastern Neuqunprovince, Argentina. In: Kay, S.M., Ramos, V.A. (Eds.), Evolution of anAndean Margin: a Tectonic and Magmatic View from the Andes to theNeuqun Basin (35 e 39 S Lat), vol. 407. Geological Society of AmericaSpecial Paper, pp. 147 e 161.

Cristallini, E.O., Comnguez, A., Ramos, V.A., 1997. Deep structure of the Met-

ne Guachipas region: tectonic inversion in Norhwestern Argentina. Journal of South American Earth Sciences 10, 403 e 421.Cristallini, E.O., Comnguez, A., Ramos, V.A., Mercerat, E.D., 2004. Basement double-

wedge thrusting in the northern Sierras Pampeanas of Argentina (27 S) econstraints from deep seismic re ection. In: McClay, K.R. (Ed.), Thrust Tectonicsand Hydrocarbon Systems. Memoir, vol. 82. AAPG, pp. 1 e 26.

De Urreiztieta, M., Gapais, G., Le Corre, C., Cobbold, P.R., Rosello, E.A., 1996. Cenozoicdextral transpression and basin development at the southern edge of theAltiplano e Puna, northwestern Argentina. Tectonophysics 254, 17 e 39.

Del Papa, C., Kirschbaum, A., Powell, J., Brod, A., Hongn, F., Pimentel, M., 2010.Sedimentological, geochemical and paleontological insights applied to conti-nental omission surfaces: a new approach for reconstructing Eocene forelandbasin in NW Argentina. Journal of South American Earth Sciences 29 (2),327 e 345.

Disalvo, A., Rodrguez Schelotto, M.L., Gmez Omil, R., Jhoffman, C., Bentez, J.,Hurtado, S., 2002. Los reservorios de la formacin Yacoraite. V Congreso deexploracin y desarrollo de hidrocarburos, Actas, 721 e 724.

Drozdzewski, G., Mon, R.,1999. Oppositely-verging thrusting structures in the northArgentine Andes compared with the German Variscides. Acta Geolgica His-pnica 34 (2 e 3), 185 e 196.

Fauqu, L.E., Strecker, M.R., 1987. Rasgos de neotectnica y avalanchas de rocas pro-ducidas por terremotos en la vertiente occidental de los nevados del Aconquija,Provincia de Catamarca, Argentina. In: Aceolaza, F., Bossi, G., Toselli, A. (Eds.),Dcimo Congreso Geolgico Argentino. Actas, vol. I, pp. 219 e 222.

Favetto, A., Pomposiello, M.C., Booker, J., Rossello, E., 2007. Magnetotelluric inver-sion constrained by seismic data in the Tucumn basin (Andean foothills, 27 S,NW Argentina). Journal of Geophysical Research, 112.

Fernndez Garrasino, C., Laf tte, G., Villar, H., 2005. Cuenca Chacoparanense. In:Chebli, G.A., Cortias, J.S., Spalletti, L.A., Legarretta, L., Vallejo, E.L. (Eds.), Fron-tera Exploratoria de la Argentina. 6 Congreso de Exploracin y Desarrollo deHidrocarburos, pp. 97 e 114.

Galliski, M.A., Viramonte, J.G., 1988. The Cretaceous paleorift in northwesternArgentina: a petrologic approach. Journal of South American Earth Sciences1, 329 e 342.

Gavriloff, I.J.C., Bossi, G.E., 1992. Revisin general, anlisis facial, correlacin y edadde las Formaciones San Jos y Ro Sal (Mioceno medio), provincias de Cata-marca, Tucumn y Salta, Repblica Argentina. Acta Geolgica Lilloana 17 (2),5e 43.



18/18

Gonzlez, O.E., 2000. Hoja Geolgica 2766-II San Miguel de Tucumn. SEGEMAR,Buenos Aires, 124 pp.

Gonzlez Bonorino, F., 1950. Algunos problemas geolgicos de las Sierras Pam-peanas. Revista de la Asociacin Geolgica Argentina 5 (3), 81 e 110.

Grier, M.E., Sal ty, J.A., Allmendinger, R.W., 1991. Andean reactivation of theCretaceous Salta rift, northwestern Argentina. Journal of South American EarthSciences 4 (4), 351 e 372.

Gutirrez, A.A., Mon, R., 2008. Macro-indicadores cinemticas en el bloque Ambato,Provincias de Tucumn y Catamarca. Revista de la Asociacin GeolgicaArgentina 63 (1), 24 e 28.

Gmez Omil, R.J., Boll, A., Hernndez, R.M., 1989. Cuenca cretcico-terciaria delNoroeste argentino (Grupo Salta). In: Chebli, G.A., Spalleti, L.A. (Eds.), CuencasSedimentrias Argentinas. Serie Correlacin Geolgica. Universidad Nacional deTucumn, San Miguel de Tucumn, pp. 43 e 64.

Hilley, G.E., Coutand, I., 2010. Links between topography, erosion, rheologicalheterogeneity and deformation in cotractional settings: Insights from thecentral Andes. Tectonophysics 95, 78 e 92.

Hindle, D., Kley, J., Oncken, O., Sobolev, S., 2005. Crustal balance and crustal uxfrom shortening estimates in the Central Andes. Earth and Planetary ScienceLetters 230, 113 e 124.

Hongn, F., del Papa, C., Powell, J., Petrinovic, I., Mon, R., Deraco, V., 2007. MiddleEocene deformation and sedimentation in the Puna-Eastern Cordillera transi-tion (23 e 26 S): control by preexisting heterogeneities on the pattern of initialAndean shortening. Geology 35, 271 e 274.

Iaffa, D.N., Sbat, F., Ferrer, O., Mon, R., Gutirrez A.A., 2008. Incipient tectonicinversion in a segmented foreland basin: From extensional to piggy-backsettings. 7th International Symposium on Andean Geodynamics, ISAG 2008,Nice, Extended Abstracts, 261 e 264.

Isacks, B.L., 1988. Uplift of the Central Andean plateau and Bending of the BolivianOrocline. Journal of Geophysical Research 93 (B4), 3211 e 3231.

Jordan, T.E., Alonso, R.N., 1987. Cenozoic stratigraphy and basin tectonics of theAndes Mountains, 20 e 28 south latitude. The American Association of Petroleum Geologists Bulletin 71 (1), 49 e 64.

Jordan, T.E., Isacks, B., Ramos, V.A., Allmendinger, R.W., 1983. Mountain building inthe Central Andes. Episodes 3, 20 e 26.

Kleinert, K., Strecker, M.R., 2001. Climate change in response to orographic barrieruplift: paleosol and stable isotope evidence from the late Neogene Santa Marabasin, northwestern Argentina. Geological Society of America Bulletin 113,728 e 742.

Kley, J., Monaldi, C.R., Sal ty, J.A., 1999. Along-strike segmentation of the Andeanforeland: causes and consequences. Tectonophysics 301, 75 e 94.

Kley, J., Monaldi, C.R., 2002. Tectonic inversion in the Santa Brbara System of thecentral Andean foreland thrust belt, northwestern Argentina. Tectonics 21 (6),1061.

Kley, J., Rosello, E.A., Monaldi, C.R., Habighorst, B., 2005. Seismic and eld evidencefor selective inversion of Cretaceous normal faults, Salta rift, northwestArgentina. Tectonophysics 399 (1/4), 155 e 172.

Mngano, M.G., Buatois, L.A., 2004. Integracin de estratigrafa secuencial, sed-imentologa e icnologa para un anlisis cronoestratigr co del Paleozoicoinferior del noroeste Argentino. Revista de la Asociacin Geolgica Argentina59, 273 e 280.

Marquillas, R.A., Sal ty, J.A., 1994. Relaciones estratigr cas regionales de la For-macion Yacoraite (Cretcico Superior), norte de la Argentina. Actas 7 CongresoGeolgico Chileno 1, 479 e 483.

Marquillas, R., del Papa, C., Sabino, I., Heredia, J., 2003. Prospeccin del lmite K/T enla cuenca del Noroeste, Argentina. The K/T boundary prospecting in theNorthwest Basin, Argentina. Revista de la Asociacin Geolgica Argentina58 (2), 271 e 274.

Masaferro, J.L., Bulnes, M., Poblet, J., Casson, N., 2003. Kinematic evolution andfracture prediction of the Valle Morado structure inferred form 3-D seismicdata, Salta province, northwest Argentina. AAPG Bulletin 87 (7), 1083 e 1104.

Mon, R., 1976. La tectnica del borde oriental de los Andes en las provincias de Salta,Tucumn y Catamarca, Republica Argentina. Revista Asociacin GeolgicaArgentina 31, 65 e 72.

Mon, R., Hogn, F.D., 1991. The structure of Precambrian and Lower Paleozoic base-ment of the Central Andes between 22 and 32 S Lat. Geologische Rundschau80 (3), 745 e 758.

Mon, R., Suayter, L., 1973. Geologa de la sierra de San Javier (provincia de Tucumn,Repblica Argentina). Acta Geolgica Lilloana 12, 155 e 168.

Monaldi, C.R., Kley, J., 1997. Balanced cross sections of the northern Santa Barbarasystem and Sierra de Zapla, Northwestern Argentina. In: VIII: Congreso Geo-logico Chileno. Chile, Antofagasta 180 e 184.

Moreno, J.A., 1970. Estratigrafa y paleogeografa del Cretcico Superior en la cuencadel Noroeste Argentino, con especial mencin de los Subgrupos Balbuena ySanta Brbara, vol. 24. Revista Asociacin Geolgica, Argentina. 9 e 44.

Mortimer, E., Carrapa, B., Coutand, I., Schoenbohm, L., Sobel, E.R., Gomez, J.S.,Strecker, M.R., 2007. Fragmentation of a foreland basin in response to out-of-sequence basement uplifts and structural reactivation: El Cajn-Campo del Are-nal basin: NW Argentina. Geological Society of America Bulletin 119, 637 e 653.

Pacheco, M.M., Mansilla, N.Y., Mon, R., Sosa, J., Piccioni, J.Y.L., 2000. The TucumnBasin as a part of the Cretaceous Continental Rift of South America. XVIILateinamerikan-Kollokium.

Padula, E., Rolleri, E.O., Mingramm, A.R., Criado Roque, P., Flores, M.A., Baldis, B.A.,1967. Devonian of Argentina. In: International Symposium on the DevonianSystem. Memoir, vol. 2. Alberta Society of Petroleum Geologists, pp. 165 e 199.

Pomposiello, M.C., Mon, R., Daz, T., 1993. The gravity eld of the Tucumn plain andits implications in the structural geology. Godynamique 6, 3 e 8.

Pomposiello, M.C., Favetto, A., Sainato, C., Booker, J., Li, S., 2002. Imaging the sedi-mentary basin of the Tucumn plain in the northern 619 Pampean rangesArgentina. Journal of Applied Geophysics 49, 47 e 58.

Porto, J., Danieli, C., Ruz Huidobro, O., 1982. El grupo Salta en la provincia deTucumn, Argentina. 58 Congreso Latinoamericano de Geologa (Buenos Aires)4, 253 e 264.

Ramos, V.A., 1988. Tectonics of the Late Proterozoic e Early Paleozoic: a collisionalhistory of southern South America. Episodes 11, 168 e 174.

Ramos, V.A., 1999. Las provincias geolgicas del territorio argentino. In: Caminos, R.(Ed.), Geologa Argentina. Anales, vol. 29. Instituto de Geologa y RecursosMinerales, pp. 41 e 96 (3).

Ramos, V.A., Alonso, R.N., 1995. El Mar Paranense en la Provincia de Jujuy. RevistaGeolgica de Jujuy 10, 73 e 80.

Reyes, F.C., Sal ty, J.A., 1973. Consideraciones sobre la estratigrafa del Cretcico(subgrupo Pirga) del noroeste argentino. V Congreso Geolgico Argentino,Carlos Paz (1972). Actas 3, 15 e 36.

Reynolds, J.H., Galli, C.I., Hernandez, R.M., Idleman, B.D., Kotila, J.M., Hilliard, R.V.,Naeser, C.W., 2000. Middle Miocene tectonic development of the Transition Zone,Salta Province, northwestern Argentina: Magnetic stratigraphy from the MetnSubgroup,Sierrade Gonzlez.Geological Society of AmericaBulletin112,1736 e 1751.

Roy, R., Cassard, D., Cobbold, P.R., Rossello, E.A., Billa, M., Bailly, L., Lips, A.L.W., 2006.Predictive mapping for copper e gold magmatic-hydrothermal systems in NWArgentina: use of a regional-scale GIS, application of an expert-guided data-driven approach, and comparison with results from a continental-scale GIS. OreGeology Reviews 29, 260 e 286.

Russo, A., Serraiotto, A., 1979. Contribucin al conocimiento de la estratigrafa ter-ciaria en el noroeste argentino. VII Congreso Geolgico Argentino, Neuqun(1978). Actas 1, 715 e 730.

Sal ty, J.A., Marquillas, R.A., 1981. Las unidades estratigr cas cretcicas del Nortede la Argentina. In: Volkheimer, W.Y., Musacchio, E. (Eds.), Cuencas Sed-imentarias del Jursico y Cretcico de Amrica del Sur, vol. 1, pp. 303 e 317.

Sal ty, J.A., Marquillas, R.M., 1994. Tectonic and sedimentary evolution of the Cre-

taceous e Eocene Salta group basin, Argentina. In: Sal ty, J.A. (Ed.), CretaceousTectonics of the Andes. Braunschweig/Wiesbaden, Earth Evolution Sciences.Friedr. Vieweg and Sohn, pp. 266 e 315.

Schmidt, C.J., Astini, R.A., Costa, C.H., Gardini, C.E., Kraemer, P.E., 1995. Cretaceousrifting, alluvial fan sedimentation and Neogene inversion, Soutern SierrasPampeanas, Argentina. In: Tankard, A.J., Surez, R., Welsink, H.J. (Eds.), Petro-leum Basins of South America. Memoir, vol. 62. AAPG, pp. 341 e 358.

Sobel, E., Strecker, M.R., 2003. Uplift, exhumation and precipitation: tectonic andclimatic control of late Cenozoic landscape evolution in the northern SierrasPampeanas, Argentina. Basin Research 15 (4), 431 e 451.

Strecker, M.R., Cerveny, P., Bloom, A.L., Malizia, D., 1989. Late Cenozoic tectonismand landscape development in the foreland of the Andes: Northern SierrasPampeanas (26 e 28 S), Argentina. Tectonics 8 (3), 517 e 534.

Toselli, J.A., Lopez, J.P., Sardi, F.G., 1999. El basamento metamr co en CumbresCalchaques noroccidentales, Aconquija, Ambato y Ancasti: Sierras Pampeanas.In: Relatorio XIV Congreso Geolgico Argentino: Geologa del NoroesteArgentino, 73 e 79.

Turic, M., Aramayo Flores, F., Gmez Omil, R., Pombo, R., Sciutto, J., Robles, D.,Caceres,A.,1987. Geologade lascuencas petrolerasde laArgentina.In: Evaluacinde las Formaciones en la Argentina. Schlumberger, Buenos Aires, pp. I/1 e I/41.

Turner, J.C.M., 1959. Estratigrafa del cordn de Escaya y de la sierra de Rinconada(Jujuy). Revista de la Asociacin Geolgica Argentina 13, 15 e 39.

Uliana, M.A., Biddle, K.T., 1988. Mesozoic e Cenozoic paleogeographic and geo-dynamic evolution of southern South America. Revista Brasileira de Geociencias18 (2), 72 e 190.


Tectonic Inversion

Documents

Transcript of Tectonic Inversion