Arc magmatic evolution is influenced by various factors, including changes in tectonic style related to subduction. In the Southern Central Andes, tectonic conditions shifted from extensional/transtensional during the early Andean stage (Early Jurassic-Early Cretaceous) to compressive/transpressive during the Late Cretaceous followed by a short-lived extensional event in the Late Cretaceous–Paleogene. To better understand magmatic evolution in this region, we present new U-Pb zircon ages, REE and Hf isotope in zircon data, geochemical analyses, and Sr-Nd isotopic data from three intrusive and subvolcanic units: the Pre-Cuyo Group (Varvarco), the Naunauco Late Cretaceous-Paleogene Belt (Varvarco-Butalón-Andacollo and Naunauco-Colipilli), and the North Patagonian Batholith (Villa Pehuenia). In Varvarco (∼36.8°S), a Jurassic age of 184 ± 3 Ma was obtained for the Jurassic Host Granite, confirming Jurassic magmatism in the area. These rocks show (ƐNd)i of −0.80 and (ƐHf)i between + 0.31 and + 5.26. Late Cretaceous-Paleogene tonalites and associated dikes (ca. 67–65 Ma), including the Butalón Tonalite, show (ƐNd)i from −0.13 to + 1.09, and (ƐHf)i from + 1.00 to + 7.81. All rocks in the area yielded Mesoproterozoic–Neoproterozoic model ages. At Naunauco and Andacollo (∼37.7°S), Late Cretaceous-Paleogene volcanic rocks from the Colipilli and Cayanta formations yield (ƐNd)i values between + 1.89 and + 4.05 and Neoproterozoic model ages, indicating a more juvenile source. At Villa Pehuenia (∼38.9°S), the Jurassic Moquehue Granite (184 ± 2 Ma) is characterized by (ƐNd)i of + 0.88 and (ƐHf)i values between + 1.71 and + 4.98. The Paso de Icalma Granodiorite (71 ± 1 Ma) has (ƐNd)i of + 2.93 and (ƐHf)i between + 6.99 and + 9.13, with Meso- to Neoproterozoic model ages. Isotopic and geochemical data suggest that Early Jurassic-Early Cretaceous magmatism had a more crustal source signature, whereas Late Cretaceous–Paleogene magmatism involved more juvenile sources. U-Pb ages and literature data support a Late Cretaceous–Paleogene steady-state event at ∼67 Ma. These data reflect changes in the tectonic style of the subducted slab. During the Jurassic-Early Cretaceous, the dominant slab roll-back and slab tearing produced extension in the back-arc region and migration of magmatism from the coast of Chile eastwards, developing back-arc deposits in an extensional environment. In the Late Cretaceous-Paleogene, the decrease in the absolute velocity of the South American plate led to an extensional regime, while the development of a slab window associated with subduction of the Farallon–Aluk ridge, together with crustal thinning, contributed to the establishment and maintenance of steady-state magmatic conditions. Preliminary zircon REE data suggest porphyry-type base metal mineralization potential for the Moquehue Granite and Butalón Tonalite.

As hydrous minerals have been observed in impact craters on Mars, impact-generated hydrothermal systems (IGHSs) have been considered as potential habitats for life on that planet. The Varge & atilde;o Dome, a 12 km wide impact structure in southern Brazil, was formed in basalts with at least two hydrothermal alteration stages. This structure is a rare terrestrial analog for IGHS evolution on Mars. However, the thermochemical evolution of these stages and their relationship to the impact remain unresolved. Two vein-forming alteration stages were identified by multidisciplinary sample analysis of Varge & atilde;o Dome. Fractured and deformed white vein fragments from the first stage occur within red veins from the second. This suggests reactivation of the white vein set during the crater excavation and modification stages. Rare Earth Element and Rb-Sr isotope data indicate different fluid sources for the white and red veins and an evolving fluid system. Thermodynamic modeling indicates a cooling sequence from 100-250 to <25 degrees C for the white vein set, whereas goethite and hematite within the red veins indicate that most IGHS activity occurred at temperatures below 40 degrees C. Considering this and accounting for gravity differences, life-supporting IGHSs on Mars may preferentially form impact structures over 28 km in diameter. Furthermore, impact-reactivation suggests elevated habitat potential in structures with pre-existing fault, fracture, and vein systems. These occur in volcanic areas or terrain older than 3.5 Ga, when Mars was wetter and geologically active. Therefore, the search for evidence of IGHS-supported life should be focused on these kinds of terrains. Plain Language Summary Asteroid impacts cause heating and fracturing of the planetary crust, leading to impact-generated hydrothermal systems (IGHSs), which may support life and lead to the formation of new minerals. Such minerals have also been found in impact craters on Mars, which makes IGHSs a potential starting point for the search for life on that planet. For a better understanding, we study a similar system on Earth: the Varge & atilde;o Dome impact structure in Brazil, in which we find that the impact affected minerals result from preexisting hydrothermalism. Additionally, the newly formed minerals, goethite and hematite, indicate temperatures below 40 degrees C-meaning that the impact-generated hydrothermal system was quite cool. Considering that the effects of impact-generated hydrothermal activity at Varge & atilde;o Dome are limited, IGHSs on Mars must have similar or more impact-generated hydrothermal activity than in Varge & atilde;o Dome to host life. This is true for structures larger than 28 km in diameter. Our data also suggest that terrains that experienced prior fracturing or hydrothermalism have a higher potential to form new IGHSs. On Mars, these systems are found in volcanic terrains and terrains older than 3.5 Ga ago. Therefore, the search for life should be focused on craters in these kinds of areas.

Recent roadworks across the 40-km-wide Araguainha impact structure (AIS) provided new, extensive exposures for mapping and structural analysis. We present an updated geological map of the AIS, highlighting Passa Dois Group Blocks (PDGBs) and the central uplift geology. Mapping indicates that faults outside the AIS likely result from pre-impact regional tectonics. The most prominent structural features in the AIS are primarily linked to the excavation and modification stages of cratering, with strain likely accommodated through detachments along interfaces between lithologic units with different rheologies. The outer rim and intermediate sections of the structure exhibit similar structural frameworks, where large, fault-bounded blocks dominate. PDGBs generally have quasi-centripetal structural vergences. In the outer rim region, PDGBs resemble gravity-driven complex slumps. There is no consistent evidence for the previously referred kilometer-scale concentric rings in the outer parts of the AIS, which had been surmised as evidence for a peak-ring configuration. PDGBs occur only between 10 km and 20 km from the structure’s center as a result of concurrent central uplift formation and crater rim collapse. The central uplift diameter is estimated at up to 20 km, and there is evidence for its asymmetric collapse. Besides rare injections of impact melt rock, the northern core comprises three types of impact breccia (suevite and polymict lithic breccia). The core can be divided into a structurally diverse megablock zone that overlies a seemingly coherent but folded and faulted crater floor of (meta)sedimentary basement. The AIS exhibits structural asymmetry that may be controlled, in part, by pre-impact anisotropy of the target.

The Chon Aike Silicic Large Igneous Province (SLIP), formed during the Jurassic break-up of Gondwana, is one of Earth's major silicic provinces. This study presents new whole-rock, mineral chemistry, and Nd isotopic data from phenorhyolitic to phenodacitic volcanic and pyroclastic rocks of the Chon Aike Formation in the Pinturas River area, western Deseado Massif, southern Argentina. These high-potassium, calc-alkaline, peraluminous ignimbrites and lavas contain oligoclase-andesine, sanidine, and magnetite-ulvospinel, with pre-eruptive temperatures ranging from 760 degrees C (magnetite-ulvospinel) to similar to 950 degrees C (feldspars), under high oxygen fugacity (-10 to -13). Estimated water contents (0.1-3%) are consistent with explosive volcanism. Isotopic data recalculated to 155 Ma indicate eNdi values between -2.26 and -0.03, pointing to a mixed crustal-mantle source with Mesoproterozoic (Grenvillian) derivation ages (TDM 0.98-1.16 Ga). When integrated with similar to 600 existing analyses from the Chon Aike SLIP, results support that geochemical differences are more spatial than temporal, shaped by tectonic setting and crustal architecture. While most domains exhibit strong crustal signatures, eNdi values near 0 in the Central domain suggest greater influence of metabasaltic components, consistent with petrogenetic models involving varying melting degrees and minor mantle input. These findings refine understanding of magmatic evolution in the Chon Aike SLIP.

We investigated the structural framework of the north-northwestern Parana Basin in Brazil to test whether the pre-impact structures in this region may have had any influence on the first-order formation and morphostructure of the Araguainha impact structure (AIS). The AIS-an similar to 40-km-diameter, erosional remnant of the largest confirmed, complex impact structure in South America-was formed approximately 259-252 Ma in a mixed sedimentary-crystalline target. We employed a multi-method approach, including airborne geophysics, remote sensing, lineament analysis, fieldwork, and modeling of the shape of the (apparent) outer rim trace. This approach reveals that prominent NE-SW- and NW-SE-trending lineaments characterize the AIS region. Much of this fabric can be linked to regional structures associated with the Paraguay Belt and, to a lesser extent, the Transbrasiliano Lineament-both of which influenced the NNW Paran & aacute; Basin during its pre-impact evolution. We present evidence that this preexisting regional structural framework partially controlled the formation and shape of the AIS. The AIS and its central uplift are asymmetric features, with the asymmetry of the central uplift evident from the time of its formation. Our results suggest that the shape of the AIS rim trace is consistent with a polygonal structure. At the analyzed scale, the AIS rim trace is best described as an irregular nine-sided polygon. This polygonal shape was likely formed during the modification stage, when crater collapse was influenced by the regional pre-impact structural fabric. Our findings improve understanding of the cratering process in structurally heterogeneous targets and provide valuable insights into the target region's subsurface structural framework.

The influence of paleorelief as an indicator of the source area is analyzed here for the Yacoraite Formation of the Balbuena Subgroup (Salta Group). Provenance analysis based on detrital zircon was performed on four samples from the Yacoraite Formation in the Maimara and Juella sections. This analysis was combined with Multidimensional Scaling (MDS) techniques and U-Pb chronology previously obtained for all units underlying the Yacoraite Formation in the Tres Cruces subbasin. For the Yacoraite samples from the Maimara section, the main sources of detrital zircons correspond to the basement units (Meson Group and Puncoviscana Complex). At the top of the Yacoraite Formation, Ordovician zircons from the Santa Victoria Group were identified. In the Juella section, a sample from the undifferentiated Pirgua Subgroup contained Triassic and Carboniferous zircons that may be derived from Permian-Triassic plutons in the Puna region of Salta Province. Other zircons from this sample, of Ordovician, Cambrian, and Neoproterozoic age, are related to the basement of the area (Santa Victoria and Meson groups, and the Puncoviscana Complex). MDS analysis indicates that the closest similarity is between the U-Pb age distributions of the Pirgua Subgroup and the Jurassic Tacuru Group. The sample from the base of the Yacoraite Formation in the Juella section contains zircons (90 %) from the basement. Additionally, Devonian zircons may originate from Devonian magmatism in southern Peru. MDS suggests similarity between the U-Pb age distributions of samples from the Lower Yacoraite Formation and the underlying units, indicating that the Pirgua Subgroup, the Meson and Santa Victoria groups, and the Puncoviscana Complex are potential sources for the lower Yacoraite Formation. In conclusion, the paleorelief of the hinterland has been a key control on the composition of the Yacoraite Formation. Detrital zircon populations for this formation can be successfully related to locally exposed sources.

The >23 km diameter, similar to 207 Ma old Rochechouart impact structure is located in the NW part of the Paleozoic basement of the French Massif Central. Despite significant erosion, this impact structure preserves a heterogeneous suite of impactites, and the transition between the crater floor and the basement. Recent textural and geochronologic studies of U-Pb on zircon from impactites and basement lithologies of this structure have shown a wide variety of shock deformation textures and age distributions. In this study, we present a comprehensive analysis combining detailed textural characterization (CL, BSE, EBSD) and U-Pb geochronological analyses at different spatial resolutions (SIMS and LA-ICP-MS) of zircon from two melt-bearing breccias (suevites) from Chassenon and Videix, and one impact melt rock (IMR) from Babaudus. The analyzed crystals display a variety of shock deformation textures. Identification of FRIGN zircon and grains with high proportions of reidite in the Videix suevite indicates that these types of shock deformation are more widespread than previously reported. In the Chassenon suevite, U-Pb age resetting increases with shock intensity, whereas in the Videix suevite, higher U and/or Th contents also appear to control resetting. In the Babaudus IMR, the similar ages for shocked granular zircons and some unshocked grains suggest that additional factors, beyond shock deformation and zircon composition, influence age resetting. The SIMS analyses yielded more reliable results after common Pb correction. The best estimate of the impact age obtained from this study is 203 +/- 4 Ma (2 sigma, MSWD = 3.4, probability = 0.065) for SIMS analyses of two granular grains from the Babaudus IMR and one granular crystal from the Videix suevite. Zircons with younger (191 +/- 4 Ma, post-impact) ages show similar characteristics to those close to the widely accepted age for the impact at 207 Ma, highlighting the challenge of distinguishing between grains and separating ages related to the impact from possible post-impact events (e.g., hydrothermal alteration). Finally, the geochronological results for the Videix and the Chassenon suevites show a clear correlation with provenance results for granitic and gneissic target lithologies, respectively. In contrast, the Babaudus IMR has an age distribution comparable with other impact melt rocks from Montoume and Recoudert but cannot be related to an identified target lithology.

Extensive, new outcrops along the MT-100 state road in the northern part of the central uplift of the 40-km diameter, 252-259 Ma old Araguainha impact structure, Central Brazil, have become available for investigation. They offer new insight into the contact relationships between the different lithologies and the genesis of different types of impact-related rocks, as well as the current level of erosion of the structure. Three types of impact melt rock (IMR) with different field relationships and compositions can now be distinguished: (1) Type-I of granitic composition and occurring mainly as veins and dikes, besides a few larger pods, in the central alkali granite core of the central uplift; (2) Type-II in the form of plastically deformed clasts of mainly highly silicious compositions in polymict impact breccia; and (3) Type-III, derived from partially melted conglomerate or sandstone precursors, and that occurs at selected sites in (meta)sedimentary strata of the basement in the immediate environs of the alkali granite core. Both polymict lithic and melt-bearing (suevitic) impact breccias are recognized in the 110-m thick integrated section through impact breccia directly overlying the crater floor. This crater floor is composed of (meta)-sedimentary basement strata with granite injections and, locally, sandstones of the Devonian sedimentary Furnas Formation of the Paran & aacute; Basin. Main breccia components are (meta)-pelites and (meta)sandstones of the basement that is currently favored to be related to the regional Paraguay Belt and to the lower sequence of the Paran & aacute; Basin sedimentary strata. Locally, breccia contains clasts of IMR Type-II, and only very rarely are granitic fragments observed. Clasts of IMR Type-I have never been observed in the breccia deposits. These new observations preclude significant involvement of alkali granite in the formation of the polymict breccia or in the production of shock melts. They also reveal the major role of the (meta)sedimentary precursors in the production of IMR by shock melting and provide essential information for better understanding the cratering processes involved in the formation of an impact structure in a sedimentary target, of the size of the Araguainha impact structure.

The Rochechouart impact structure in the northwestern part of the French Massif Central (FMC) has a great diversity of impactites, including monomict impact breccias, suevite, and impact melt rocks (IMRs). The structure is strongly eroded, which allows the study of impactites of the crater fill and the transition into the crater floor. The FMC has had a multistage geological evolution from the late Neoproterozoic to the Ordovician (600-450 Ma) until the later stages of the Variscan orogeny (similar to 300 Ma). Previous geochronological work on Rochechouart has been focused mainly on the impactites and constraining the impact age, and scarce work has been done on the FMC-related target rocks. Here, U-Pb isotope analysis by LA-MC-ICP-MS has been conducted on zircon from two IMRs from the Recoudert and Montoume localities, and from a monzodiorite, a paragneiss, and two amphibolite samples of the basement to the impact structure. Zircon from the target rocks yielded mainly Neoproterozoic to Carboniferous ages (similar to 924 to similar to 301 Ma) that can mostly be correlated to different stages of the geological evolution of the FMC. The monzodiorite also yielded a Permian age of 272 +/- 12 Ma. Zircon from the IMRs, and especially from the Montoume sample, gave a comparatively higher diversity of Neoproterozoic to Jurassic ages (similar to 552 to similar to 195 Ma). Provenance analysis for the zircon age populations of the impactites compared to those of the basement rocks shows overall poor correlation between the two age groups. This suggests that other target lithologies were involved in the formation of these impact melts as well. Post-Variscan and preimpact ages (281-226 Ma) obtained for both melt rocks probably reflect a previously unconstrained event in the evolution of the regional geological history. Ages similar to the currently most widely accepted impact age of similar to 204-206 Ma were obtained from both IMR samples. In addition, the Montoume melt rock yielded several post-204 Ma ages, which might reflect a to date unconstrained, about 194 Ma postimpact thermal/hydrothermal event.

The geodynamic setting across the Paleozoic to Mesozoic transition in Patagonia and the Antarctic Peninsula (SW Pangea) has been strongly debated. Hypotheses of terrane accretion, episodes of shallower to flattened subduction, long-lived stages of crustal extension, or even subduction arrest have been variably proposed. We have compiled and re-evaluated the available whole-rock geochemistry and zircon Hf-isotope data for Permian to Triassic rocks from Patagonia and the Antarctic Peninsula, and compared these findings with the orogenic events in these regions. We have identified that two orogenic cycles occurred along the SW margin of Pangea during the PermianTriassic interval, namely the Gondwanide and Chonide/Peninsula orogenies. Both orogenies coexisted with the development of magmatic arcs; the Permian arc exhibits an overall I-type signature that switched to A-type towards ca. 252 Ma, whereas the Triassic arc has an S-type signature in the Antarctic Peninsula and intraplate features in Patagonia. The Hf isotope data for zircon exhibit broadly subchondritic values, suggesting significant crustal contribution in the magmatic source during both cycles. The short- and long-term temporal behavior of the isotopic trends suggests variations that may be attributable to the participation of primitive and/or evolved sources. We conclude that the geochemical and isotopic signatures of the magmas, together with different styles of crustal deformation, resulted from the interaction of the upper and lower plates, consistent with the evolution of an accretionary-type margin along SW Pangea during Permian and Triassic times.

The western margin of SW Gondwana was a place of active convergence between the Gondwana shield and the oceanic lithosphere of the Panthalassa Ocean during most of the Paleozoic. However, several studies have indicated that especially to the north of latitude 22°S, the Devonian−early Carboniferous was a time of relative quiescence without magmatic activity, metamorphism, or deformation. This interval has been termed the “Devonian Problem.” As the Devonian−Carboniferous is extensively well represented by over 4000-m-thick sedimentary sequences in the Tarija Basin in the Southern Bolivian Subandean Zone, provenance analyses—U-Pb isotope analysis on detrital zircon, Sr-Nd whole-rock isotope analysis, and X-ray diffraction (XRD)—were conducted on stratigraphically controlled sedimentary units to attempt to constrain the tectonic setting of the basin during that time. U-Pb on zircon provenance analysis indicates that only the Carboniferous units show input from comparatively young sources (<14%), with ages between 420 Ma and 320 Ma, which can be correlated with a Devonian magmatic arc. The dominant source areas for Devonian−Carboniferous sediment were the Sierras Pampeanas to the southwest and the Arequipa-Antofalla Massif and Famatinian Arc to the west, besides a few zircon grains (<18% of dates) that were possibly derived from pre-Andean inliers with ages typically >1800 Ma. The combined Sr-Nd isotope and XRD results for the pelites and the multidimensional scaling (MDS) analysis indicate that the Carboniferous units most likely represent reworked material from older units, with a minor contribution from the western part of the basin. All currently available data lead us to propose that the Tarija Basin developed during the Devonian−Carboniferous in a foreland basin setting related to the convergent margin, with important glacial sedimentary input from the continent during the Carboniferous. The absence of a contribution from a concomitant magmatic arc for the Devonian units of the Tarija Basin and the scarce magmatic zircon input (<14%) into the Carboniferous units indicate a shift from flat-slab subduction during the Devonian to normal subduction during the Carboniferous following complete delamination of the flat slab. Our comparison of the detrital record for the Tarija Basin with that of the Paraná, Chaco-Paraná, Sauce Grande, Paganzo, Navidad Arizaro, Madre de Dios, and Karoo basins supports an active margin setting for the SW margin of Gondwana during this time interval.

Contains detailed information about rock sampling and analytical methods used for the development of this work. Also includes tables and supplementary images.

Genesis and emplacement of Vredefort Granophyre, the impact melt rock exposed on the Vredefort Dome, the erosional remnant of the central uplift of the Vredefort impact structure, South Africa, have long been debated. This debate was recently reinvigorated by the discovery that besides the previously known felsic variety of >66 wt% SiO2, a second, somewhat more mafic phase of <66 wt% SiO2 occurs along a Granophyre dike on farms Kopjeskraal and Eldorado in the northwest sector of the dome. Two hypotheses have been put forward to explain the genesis and emplacement of this second phase: (1) successive injections of impact melt into extensional fractures opened in the course of central uplift formation/crater modification, with melts of distinct compositions derived from a differentiating impact melt body in the crater, and (2) generation of the more mafic phase as a product of admixture/assimilation of a mafic country rock component, either the so‐called epidiorite of possible Ventersdorp Supergroup affiliation or the Dominion Group meta‐lava (DGL), to Felsic Granophyre. In the latter model, contamination with mafic country rock would have occurred during downward intrusion and stoping into and below the crater floor. The so‐called Mafic Granophyre has previously only ever been sampled on a single site (Farm Kopjeskraal). In this study, samples of Granophyre occurring along the southerly extension of this dike on farm Rensburgdrif, and from a second dike on the Rietkuil property further southwest were investigated by field work, and petrographic, geochemical, and isotopic analysis. The mafic phase indeed occurs in the interior of the dike at Rensburgdrif, and also on Rietkuil. New geochemical and Sr‐Nd isotope data support the hypothesis that the Mafic Granophyre composition represents a mixture between Felsic Granophyre and a mafic country rock. A 20% admixture of epidiorite or DGL to Felsic Granophyre provides an excellent match for the chemical composition of the Mafic Granophyre. The Sr‐Nd isotope data indicate that this admixture likely involved the epidiorite component rather than DGL. Together with earlier Sr‐Nd‐Os‐Se isotopic data, and other geochemical data, these results further support formation of the Mafic Granophyre by local assimilation/admixture of epidiorite to Felsic Granophyre.

The Sofía-Julia-Valencia vein system, located in the Andacollo mining district in central west Argentina, is hosted by ENE-WSW oriented strike-slip faults which are the result of reactivation of normal faults affecting Carboniferous to Jurassic rocks during Upper Cretaceous-Paleogene. These veins contain a total resource of 22,900 Oz of gold with 5.5-6.7 g/t AuEq. Geologic mapping and a U-Pb age of 71±1Ma in zircon, obtained in an altered and mineralized dacitic dyke of the district, allowed to associate the mineralizing event to the Naunauco Andesitic belt magmatism (Upper Cretaceous-Paleogene) and to the Cretaceous-Paleogene Metallogenic Belt of the Andes in southwestern Argentina. The ore bodies are made up of multiple veins and veinlets that, from oldest to youngest, correspond to: (1) scarce early quartz+pyrite+molybdenite+iron poor-sphalerite veinlets, (2) quartz+epidote+calcite±albite (apatite+rutile+titanite+light rare earth elements bearing phosphates) associated with quartz+biotite, epidote (actinolite)+chlorite+calcite, with pyrite+pyrrhotite±chalcopyrite±(iron rich-sphalerite), marcasite veins. These veins are cut and reopened by (3) polymetallic veins and veinlets formed by quartz+sericite±carbonates (chlorite), with iron-gold rich sphalerite+silver rich-galena+chalcopyrite+pyrite, native gold±arsenopyrite±(pyrrhotite, bornite, argentite). Pyrite (4) and (5) carbonate+framboidal pyrite veinlets cuts all the previous ones. Multistage carbonate generation brecciate and cut previous veins and veinlets. Quartz shows granular, comb textures and some calcites developed platy textures. Four hydrothermal alteration types affected the veins host rock: (1) patches of early potassic alteration; (2) widespread propylitic alteration with disseminated sulfides; (3) later phyllic alteration overlapped to the previous ones; and (4) late supergene alteration. The sphalerite and chlorite composition in the veins (1 and 2) along with their mineral assamblages indicates they were formed by initially alkaline fluids (e.g., feldspar stable) with intermediate sulfur and oxygen fugacity and mesothermal temperature conditions (~400-240 °C), that evolved to conditions of lower sulfur (e.g., pyrrhotite stable) and oxygen fugacity, temperature

The Aconcagua region constitutes a classical site to study the growth of the Andes, being host of the highest mountain of South America and focus of numerous investigations since its first description by Charles Darwin almost 200 years ago. The last detailed works in this area characterized it as a typical thin-skinned fold-thrust belt with a basal detachment located in the lower evaporitic units of the Mesozoic sequences. Previous authors in this area correlated the different thrust sheets on the basis of their marine fossils, sedimentological characteristics and structural relations. Although these criteria were useful for the identification of the marine and evaporitic units, the resemblance between the nonmarine red beds and among the different volcanic units has difficulted their unequivocal assignment. Moreover, the inaccessibility of the outcrops and the lack of an adequate geochronological control has led to underestimate the importance of the Aconcagua fold-thrust belt in the last couple of years, being characterized as a secondary feature in Andean orogenesis. A series of new field observations, sedimentological studies and geochronological analyses were performed to update the geological map of this area and build a schematic cross section along the Río Cuevas at 32°50’S in west-central Argentina. These studies allowed the identification of important variations on the thickness of the Upper Jurassic nonmarine sequences associated with the activity of normal faults and the development of structural highs. Many of these normal faults are presently inverted, which suggests that tectonic inversion played an important role in the structuration of this region, leading to a deformational style that varies from a thick-skinned inner domain towards a thin-skinned frontal sector. A series of sedimentological profiles aided by four new U-Pb detrital zircon analyses and its integration with new geochronological databases allowed the documentation of previously unrecognized Paleogene deposits, the age reassignation of several volcanic and sedimentary units and the modification of the stratigraphy. Finally, at least three contractional events with different structural mechanisms were identified along this transect, revealing a dynamic tectonic evolution that underscores the role of structural inheritance and the relevance of the Aconcagua fold-thrust belt in the Andean orogeny.