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The Andes of western Argentina record spatiotemporal variations in morphology, basin geometry, and structural style that correspond with changes in crustal inheritance and convergent margin dynamics. Above the modern Pampean flat‐slab subduction segment (27–33°S), retroarc shortening generated a fold‐thrust belt and intraforeland basement uplifts that converge north of ∼29°S, providing opportunities to explore the effects of varied deformation and subduction regimes on synorogenic sedimentation. We integrate new detrital zircon U‐Pb and apatite (U‐Th)/He analyses with sequentially restored, flexurally balanced cross sections and thermokinematic models at ∼28.5–30°S to link deformation with resulting uplift, erosion, and basin accumulation histories. Tectonic subsidence, topographic evolution, and thermochronometric cooling records point to (a) shortening and distal foreland basin accumulation at ∼18–16 Ma, (b) thrust belt migration, changes in sediment provenance, and enhanced flexural subsidence from ∼16 to 9 Ma, (c) intraforeland basement deformation, local flexure, and drainage reorganization at ∼12–7 Ma, and (d) out‐of‐sequence shortening and exhumation of foreland basin fill by ∼8–2 Ma. Thrust belt kinematics and the reactivation of basement heterogeneities strongly controlled tectonic load configurations and subsidence patterns. Geo/thermochronological data and model results resolve increased shortening and combined thrust belt and intraforeland basement loading in response to ridge collision and Neogene shallowing of the subducted oceanic slab. Finally, this study demonstrates the utility of integrated flexural thermokinematic and erosion modeling for evaluating the geometries, rates, and potential drivers of retroarc deformation and foreland basin evolution during changes in subduction. Key Points: New geo/thermochronological results and flexural thermokinematic models constrain Andean retroarc thrust belt and foreland basin evolutionModels highlight the influence of deformation kinematics and thrust belt/basement load configurations during retroarc subsidenceSubduction shallowing at ∼12 Ma drove increased shortening and flexurally controlled topography/subsidence with no residual dynamic signals [ABSTRACT FROM AUTHOR]

The Aure fold-thrust belt is an important area for oil and gas exploration in Papua New Guinea, but the structural deformation and evolution of the fold-thrust belt are not well understood.In this paper, 2D and 3D seismic data, drilling and geological data covering the structural belt, combined with previous geological research results, were used to identify the structure and kinematics characteristics of the Aure fold-thrust belt.Guided by the theory of fault-related folds, the seismic data are interpretation.The Aure fold-thrust belt can be divided into three sections along the strike, and the structural deformation of the belt has obvious differences, which are mainly reflected in the following aspects: ①In the trend from NE to SW, the deformation level is gradually shallow, the involved strata are gradually new, and the deformation degree is gradually weaker; ②Along the strike from NW to SE, the extension range becomes smaller, the foreland sedimentary strata become newer, the tectonic deformation time becomes later, the shortening rate becomes larger, and the shortening amount becomes smaller; ③The western section and the middle section are disintegrated vertically, and the eastern section is inherited deformation.The results can provide basin evidence for oil and gas exploration in Papua New Guinea and regional tectonic evolution in the northern margin of Australia.

[Display omitted] • Late Jurassic to Cenozoic tectonostratigraphic evolution of the Andes at 36°S. • End of backarc sedimentation during the Late Cretaceous. • Upper Cretaceous compression did not generate a well-developed fold-thrust belt. • Modest shortening, tectonic quiescence, and extension during most of the Paleogene. • A well-developed fold-thrust belt was only achieved in the Neogene. Many studies propose a significant shift in the tectonic and paleogeographic evolution of the Andes in south-central Chile and Argentina during the Late Cretaceous. It has been proposed that the preceding Jurassic-Early Cretaceous extensional regime that resulted in a low-relief volcanic arc and the backarc Neuquén basin came to an end, giving way to shortening and Andean growth from the Late Cretaceous onward. Nevertheless, there are disagreements regarding the timing and nature of this transition to Andean orogenesis. To address these issues, we conducted geochronologic (U–Pb and 40Ar/39Ar), sedimentologic, and structural studies on Mesozoic-Cenozoic sedimentary and volcanic rocks in the Río Maule area (Principal Cordillera, Chile, 36°S). From our findings and prior analyses, we propose the following tectono-stratigraphic evolution of the region. (1) Marine deposition of the Tithonian-Hauterivian Baños del Flaco Formation took place in an extensional backarc basin. (2) After a ∼ 40 Myr hiatus, fluvial deposits of the Colimapu Formation and volcanic rocks of the Plan de los Yeuques Formation accumulated during the Cenomanian-Danian. Whereas the Colimapu Formation displays evidence of syndepositional shortening, the Plan de los Yeuques Formation exhibits synextensional growth strata. Contrary to other studies, our results suggest that the Chilean part of the Principal Cordillera was largely a zone of active deposition rather than an elevated fold-thrust belt during the Late Cretaceous. We propose that sedimentation occurred within a series of relatively stable intermontane subbasins generated by shortening, followed by extension. (3) After a ∼ 20 Myr hiatus, middle Eocene to early Miocene (Lutetian-Aquitanian) accumulation of a thick succession of andesitic lavas and minor clastic sediments of the Abanico Formation occurred in an intraarc extensional basin. (4) Finally, major shortening and uplift of previously deposited Mesozoic-Cenozoic rocks took place throughout the Neogene. This phase constituted the primary contractional deformation in the Andes of south-central Chile and Argentina. In terms of the transition to early Andean deformation, we propose that structural deformation did not generate a major, regional-scale fold-thrust belt during the late Albian-Santonian. Modest extension, tectonic quiescence, or low-magnitude shortening seem to have dominated during the early to middle Cenozoic. [ABSTRACT FROM AUTHOR]

The Bolivian Andes are an archetypal convergent margin orogen with a paired fold-thrust belt and foreland basin. Existing chronostratigraphic constraints highlight a discrepancy between unroofing of the Eastern Cordillera and Interandean Zone fold-thrust systems since 40 Ma and the onset of rapid sediment accumulation in the Subandean Chaco foreland after 11 Ma, previously attributed to Miocene climate shifts. New results from magnetostratigraphic, backstripping, erosional volumetric calculations, and flexural modeling efforts are integrated with existing structural and thermochronologic datasets to investigate the linkages between shortening, exhumation, and subsidence. Magnetostratigraphic and backstripping results determine tectonic subsidence in the Chaco foreland basin, which informs flexural models that evaluate topographic load and lithospheric parameters. These models show that Chaco foreland subsidence is consistent with a range of loading scenarios. Eroded volumes from the fold-thrust belt were sufficient to fill the Chaco foreland basin, further supporting the linkage between sediment source and sink. Erosional beveling of the Eastern Cordillera, local intermontane sediment accumulation after 30–25 Ma, and regional development of the high-elevation San Juan del Oro geomorphic surface from 25 to 10 Ma suggest that the western Eastern Cordillera did not store the large sediment volume expected from erosion of the fold-thrust belt, which arrived in the Subandean Zone after 11 Ma. Eocene to middle Miocene foreland basin accumulation was likely focused between the Eastern Cordillera and Interandean Zone, and has been almost completely recycled into the modern Subandean foreland basin. The delay between initial fold-thrust belt exhumation (early Cenozoic) and rapid Subandean subsidence (late Cenozoic) highlights the interplay between protracted shortening, underthrusting, and foreland basin recycling. Only with sufficient crustal shortening, accommodated by eastward advance of the fold-thrust belt and attendant underthrusting of Brazilian Shield lithosphere beneath the Subandes, did the Subandean zone enter proximal foreland basin deposystems after ca. 11 Ma. Prior to the late Miocene, the precursor flexural basin was situated westward and not wide enough to incorporate the distal Subandean Zone. These results highlight the interplay between a range of crustal and surface processes linked to tectonics and Miocene climate shifts on the evolution of the southern Bolivian Andes.

The Sivas Basin overlaps the northern Neotethys suture zone in central Anatolia (Turkey) and contains a ca. 12-km thick succession of Cenozoic strata that provides an exceptional record of major tectonic transitions from subduction to continental assembly and tectonic escape. Consensus regarding the tectonic and palaeogeographic evolution of this segment of the Arabia-Eurasia collision zone has been hindered by uncertainty in the tectonic setting of the early (Palaeogene) Sivas Basin, which has been variably interpreted as a remnant ocean, forearc, foreland, wedge-top or intracontinental extensional basin. Here we integrate new geologic mapping (>5,000 km2), stratigraphy, facies analysis and U-Pb geochronology from the western Sivas Basin to produce a detailed time-stratigraphic framework and a refined Palaeogene tectono-sedimentary model for the Sivas Basin. Earliest marine sedimentation occurred during the Maastrichtian-Palaeocene in a remnant ocean setting due to incomplete closure of the northern Neotethys Ocean. Rapid accumulation of >2 km of basin floor turbidites during the middle to late Eocene reflect a transition to a foreland setting. A major late Eocene unconformity (ca. 38-34 Ma) coincides with the initiation of the north-vergent southern Sivas fold-thrust belt, which inverted and structurally partitioned the basin into a southern wedge-top and a northern evaporitic foreland basin; the entire basin was dominantly nonmarine after this unconformity. Published palaeomagnetic data integrated with a newly discovered tuff dated at 31.9 Ma reveal that the 2.8-km thick Altinyayla Formation was deposited from ca. 34 to 26 Ma in an unconfined braided fluvial system. Close stratigraphic correlations between the western, central and northern Sivas Basin suggest that the entire basin evolved from a remnant ocean to peripheral retro-foreland basin during the middle to late Eocene, and finally a fragmented foreland basin since the Oligocene. This general evolution may be a characteristic of such sedimentary basins formed on suture zones across Anatolia and in other collisional orogens globally. [ABSTRACT FROM AUTHOR]

In the northwestern sector of the Zagros foreland basin, axial fluvial systems initially delivered fine‐grained sediments from northwestern source regions into a contiguous basin, and later transverse fluvial systems delivered coarse‐grained sediments from northeastern sources into a structurally partitioned basin by fold‐thrust deformation. Here we integrate sedimentologic, stratigraphic, palaeomagnetic and geochronologic data from the northwestern Zagros foreland basin to define the Neogene history of deposition and sediment routing in response to progressive advance of the Zagros fold‐thrust belt. This study constrains the depositional environments, timing of deposition and provenance of nonmarine clastic deposits of the Injana (Upper Fars), Mukdadiya (Lower Bakhtiari) and Bai‐Hasan (Upper Bakhtiari) Formations in the Kurdistan region of Iraq. Sediments of the Injana Formation (~12.4–7.75 Ma) were transported axially (orogen‐parallel) from northwest to southeast by meandering and low‐sinuosity channel belt system. In contrast, during deposition of the Mukdadiya Formation (~7.75–5 Ma), sediments were delivered transversely (orogen‐perpendicular) from northeast to southwest by braided and low‐sinuosity channel belt system in distributive fluvial megafans. By ~5 Ma, the northwestern Zagros foreland basin became partitioned by growth of the Mountain Front Flexure and considerable gravel was introduced in localized alluvial fans derived from growing topographic highs. Foredeep accumulation rates during deposition of the Injana, Mukdadiya and Bai‐Hasan Formations averaged 350, 400 and 600 m/Myr respectively, suggesting accelerated accommodation generation in a rapidly subsiding basin governed by flexural subsidence. Detrital zircon U‐Pb age spectra show that in addition to sources of Mesozoic‐Cenozoic cover strata, the Injana Formation was derived chiefly from Palaeozoic‐Precambrian (including Carboniferous and latest Neoproterozoic) strata in an axial position to the northwest, likely from the Bitlis‐Puturge Massif and broader Eastern Anatolia. In contrast, the Mukdadiya and Bai‐Hasan Formations yield distinctive Palaeogene U‐Pb age peaks, particularly in the southeastern sector of the study region, consistent with transverse delivery from the arc‐related terranes of the Walash and Naopurdan volcano‐sedimentary groups (Gaveh‐Rud domain?) and Urumieh‐Dokhtar magmatic arc to the northeast. These temporal and spatial variations in stratigraphic framework, depositional environments, sediment routing and compositional provenance reveal a major drainage reorganization during Neogene shortening in the Zagros fold‐thrust belt. Whereas axial fluvial systems initially dominated the foreland basin during early orogenesis in the Kurdistan region of Iraq, transverse fluvial systems were subsequently established and delivered major sediment volumes to the foreland as a consequence of the abrupt deformation advance and associated topographic growth in the Zagros. [ABSTRACT FROM AUTHOR]

A source‐to‐sink analysis incorporating geochronometric and thermochronometric data from the Sevier fold‐thrust belt (SFTB) and proximal synorogenic strata of the Canyon Range Conglomerate (CRC) and Indianola Group (IG) provides new insights into orogenic exhumation, erosional unroofing, and the interplay between thrusting and coarse clastic deposition in the Cretaceous Cordilleran foreland basin of western North America. Zircon (U‐Th)/He ages from the Pavant and Nebo thrust sheets record significant Cenomanian cooling indicative of synchronous exhumation and thrusting along a large segment of the SFTB in central and northern Utah. Detrital zircon (U‐Th)/He (DZHe) ages indistinguishable from depositional ages from the Cenomanian Dakota Formation and lower CRC also record rapid unroofing of the SFTB and synchronous deposition. DZHe data from wedge‐top deposits of the CRC record two significant unroofing episodes: Albo‐Cenomanian exhumation of the Pavant thrust and progressive unroofing of the Canyon Range culmination. For the IG, the presence of Paleozoic DZHe ages along with Paleozoic‐Mesozoic DZ U‐Pb ages in the Cenomanian Sanpete Formation suggests derivation from Paleozoic to Jurassic strata exhumed in the frontal Pavant and Nebo thrust sheets. After the Cenomanian episode of rapid exhumation, proximal foredeep strata recorded a widespread DZ provenance shift in the Turonian. Short DZHe lag time values from Campanian CRC and IG deposits reveal rapid exhumation of the SFTB during the Campanian. The synchroneity of major shortening and Campanian and Cenomanian changes in foreland basin architecture and provenance supports models proposing that active shortening in the fold‐thrust belt coincides with coarse clastic influx in foreland basins. Key Points: ZHe ages from the Canyon Range and southern Provo salient constrain major exhumation of both the Pavant and Nebo Thrusts to ~102–96 MaShort lag time ZHe ages in the Cow Canyon Member and Dakota Formation link active thrust belt deformation to major sediment dispersionDZ U‐Pb and DZHe maximum depositional ages in the proximal foreland basin help confirm litho‐ and bio‐stratigraphic correlations [ABSTRACT FROM AUTHOR]

The southern Central Andes recorded retroarc shortening, basin evolution, and magmatic arc migration during Neogene changes in subduction. At 31–33°S, above the modern flat‐slab segment, spatial and temporal linkages between thin‐ and thick‐skinned foreland shortening, basement‐involved exhumation of the main Cordillera, and lower‐crustal hinterland thickening remain poorly resolved. We integrate new geochronological and thermochronological data for thrust sheets and Neogene foreland basin fill with structural, sedimentological, and passive seismic results to reconstruct the exhumation history and evaluate potential geometric linkages across structural domains. 40Ar/39Ar ages for volcanic horizons and zircon U‐Pb ages for synorogenic clastic deposits in the Manantiales Basin constrain the minimum duration of synorogenic sedimentation to ~22–14 Ma. Detrital zircon age distributions record sequential unroofing of hinterland thrust sheets until ~15 Ma, followed by eastward (cratonward) advance of the deformation front, shutoff of western sediment sources, and a shift from fluvial to alluvial fan deposition at ~14 Ma. Apatite (U‐Th)/He cooling ages confirm rapid exhumation of basement‐involved structural blocks and basin partitioning by ~14–5 Ma, consistent with the timing of the Manantiales facies and provenance shifts and a coeval (~12–9 Ma) pulse of thin‐skinned shortening and exhumation previously identified in the eastern foreland. Late Miocene–Pliocene (~8–2 Ma) cooling ages along the Chile‐Argentina border point to hinterland uplift during the latest stage of Andean orogenesis. Finally, geophysical constraints on crustal architecture and low‐temperature thermochronometry results are compatible with a hybrid thin‐ and thick‐skinned décollement spanning retroarc domains. Key Points: 40Ar/39Ar and zircon U‐Pb ages constrain the minimum duration of synorogenic accumulation in the Neogene Manantiales Basin to ~22–14 MaForeland basin strata record sequential unroofing of hinterland thrust sheets, then regionally synchronous shortening by ~14–12 MaGeo/thermochronological data and thermo‐kinematic models are compatible with hybrid thin‐ and thick‐skinned retroarc deformation [ABSTRACT FROM AUTHOR]

Abstract The southern Central Andes of Argentina and Chile (27–40°S) are the product of deformation, arc magmatism, and basin evolution above a long-lived subduction system. With sufficient timing and provenance constraints, Andean stratigraphic and structural records enable delineation of Mesozoic-Cenozoic variations in subsidence and tectonic regime. For the La Ramada Basin in the High Andes at ∼31–33°S, new assessments of provenance and depositional age provided by detrital zircon U-Pb geochronology help resolve deformational patterns and subsidence mechanisms over the past ∼200 Myr. Marine and nonmarine clastic deposits recorded the unroofing of basin margins and sediment contributions from the Andean magmatic arc during Late Triassic to Early Cretaceous extension, thermal subsidence, and possible slab rollback. Subsequent sediment delivery from the Coastal Cordillera corresponded with initial flexural accommodation in the La Ramada Basin during Andean shortening of late Early Cretaceous to Late Cretaceous age. The architecture of the foreland basin was influenced by the distribution of precursor extensional depocenters, suggesting that inherited basin geometries provided important controls on later flexural subsidence and basin evolution. Following latest Cretaceous to early Paleogene tectonic quiescence and a depositional hiatus, newly dated deposits in the western La Ramada Basin provide evidence for a late Paleogene episode of intra-arc and proximal retroarc extension (development of the Abanico Basin, principally in Chile, at ∼28–44°S). Inversion of this late Paleogene extensional basin system during Neogene compression indicates the southern Central Andes were produced by at least two punctuated episodes of shortening and uplift of Late Cretaceous and Neogene age. Highlights • Zircon U-Pb ages constrain provenance during Triassic–Paleogene basin evolution. • Extensional basin geometry influenced later thermal and flexural foreland subsidence. • Cretaceous–Neogene shortening was disrupted by neutral–extensional tectonic regimes. [ABSTRACT FROM AUTHOR]

The Zagros fold-thrust belt in the Kurdistan region of Iraq encroached southward toward a rapidly subsiding Neogene foreland basin and was later partitioned by out-of-sequence shortening focused along the Mountain Front Flexure (MFF), as defined by new low-temperature thermochronologic, stratigraphic, and provenance results. Apatite (U-Th)/He ages document rapid deformation advance from the Main Zagros Fault to southern frontal structures (Kirkuk, Shakal, and Qamar thrusts) at ~ 10–8 Ma, followed by potential basement-involved out-of-sequence development of the MFF (Qaradagh anticline) by ~ 5 Ma. Distinct shifts in detrital zircon U-Pb provenance signatures for Neogene foreland basin fill provide evidence for drainage reorganization during fold-thrust belt advance. U-Pb age spectra and petrologic data from the Injana (Upper Fars) Formation indicate derivation from a variety of Eurasian, Pan-African, ophiolitic and Mesozoic-Cenozoic volcanic terranes, whereas the Mukdadiya (Lower Bakhtiari) and Bai-Hasan (Upper Bakhtiari) Formations show nearly exclusive derivation from the Paleogene Walash-Naopurdan volcanic complex near the Iraq-Iran border. Such a sharp cutoff in Eurasian, Pan-African, and ophiolitic sources is likely associated with drainage reorganization and tectonic development of the geomorphic barrier formed by the MFF. As a result of Zagros crustal shortening, thickening and loading, the Neogene foreland basin developed and accommodated an abrupt influx of fluvial clastic sediment that contains growth stratal evidence of synkinematic accumulation. The apparent out-of-sequence pattern of upper crustal shortening in the hinterland to foreland zone of Iraqi Kurdistan suggests that structural inheritance and the effects of synorogenic erosion and accumulation are important factors influencing the irregular and episodic nature of orogenic growth in the Zagros. [ABSTRACT FROM AUTHOR]

The temporal transition from backarc extension to retroarc shortening is a fundamental process in the evolution of many Andean-type convergent margins. This switch in tectonic regime is preserved in the 5–7 km thick Mesozoic-Cenozoic stratigraphic record of west-central Argentina at 34–36°S, where the northern Neuquén Basin and succeeding Cenozoic foreland succession chronicle a long history of fluctuating depositional systems and diverse sediment source regions during Andean orogenesis. New findings from sediment provenance and facies analyses are integrated with detrital zircon U-Pb geochronological results from 16 samples of Jurassic through Miocene clastic deposits to delineate the progressive exhumation of the evolving Andean magmatic arc, retroarc fold-thrust belt, and foreland province. Abrupt changes in provenance and depositional conditions can be reconciled with a complex Mesozoic-Cenozoic history of extension, postextensional thermal subsidence, punctuated tectonic inversion, thick- and thin-skinned shortening, overlapping igneous activity, and alternating phases of basin accumulation, sediment bypass, and erosion. U-Pb age distributions constrain the depositional ages of Cenozoic units and reveal a prolonged late middle Eocene to earliest Miocene (roughly 40–20 Ma) hiatus in the retroarc foreland basin. This stratigraphic gap is expressed as a regional disconformity that marks a pronounced shift in depositional conditions and sediment sources, from (i) slow Paleocene–middle Eocene accumulation of distal fluviolacustrine sediments (Pircala and Coihueco Formations) contributed from far western magmatic arc sources (Cretaceous–Paleogene volcanic rocks) and subordinate eastern basement rocks (Permian-Triassic Choiyoi igneous complex) to (ii) rapid Miocene–Quaternary accumulation of proximal fluvial to megafan sediments (Agua de la Piedra, Loma Fiera, and Tristeza Formations) recycled from emerging western thrust-belt sources of Mesozoic basin fill originally derived from basement and magmatic arc sources. The mid-Cenozoic stratigraphic gap signified ∼20 Myr of nondeposition, potentially during passage of a flexural forebulge or during neutral to extensional conditions driven by mechanical decoupling and a possible retreating-slab configuration along the Nazca-South America plate boundary. Neogene eastward propagation of the Malargüe fold-thrust belt involved basement inversion with geometrically and kinematically linked thin-skinned shortening at shallow foreland levels, including late Miocene deposition of accurately dated 10.5–7.5 Ma growth strata and ensuing displacement along the frontal emergent and blind thrust structures. Subsequent partitioning and exhumation of Cenozoic clastic fill of the Malargüe foreland basin has been driven by inboard advance of arc magmatism and Pliocene-Quaternary uplift of the San Rafael basement block farther east. [ABSTRACT FROM AUTHOR]

Andean Cenozoic shortening within the Malargüe fold–thrust belt of west-central Argentina has been dominated by basement faults largely influenced by pre-existing Mesozoic rift structures of the Neuquén basin system. The basement contractional structures, however, diverge from many classic inversion geometries in that they formed large hanging-wall anticlines with steeply dipping frontal forelimbs and structural relief in the order of several kilometres. During Cenozoic E–W shortening, the reactivated basement faults propagated into cover strata, feeding slip to shallow thrust systems that were later carried in piggyback fashion above newly formed basement structures, yielding complex thick- and thin-skinned structural relationships. In the adjacent foreland, Cenozoic clastic strata recorded the broad kinematic evolution of the fold–thrust belt. We present a set of structural cross-sections supported by regional surface maps and industry seismic and well data, along with new stratigraphic information for associated Neogene synorogenic foreland basin fill. Collectively, these results provide important constraints on the temporal and geometric linkages between the deeper basement faults (including both reactivated and newly formed structures) and shallow thin-skinned thrust systems, which, in turn, offer insights for the understanding of hydrocarbon systems in the actively explored Neuquén region of the Andean orogenic belt. [ABSTRACT FROM PUBLISHER]

The thin-skin Sevier and thick-skin Laramide belts of the North American Cordillera provide a long-term record of the interrelations between evolving styles of mountain building and plate dynamics over a complete tectonic cycle, from onset of rapid subduction, to protracted growth of a composite orogenic system, to final collapse. Primary architecture of basement and sedimentary cover rocks, which included a thick passive margin section deposited along the western continental margin, influenced patterns of subsequent deformation. The Cordilleran orogenic system, comprised of an interrelated forearc accretionary complex, magmatic arc, retroarc hinterland, Sevier fold-thrust belt, and foreland basin locally deformed by Laramide arches, developed during Jurassic to Paleogene Andean-style subduction and terrane accretion. The Sevier belt formed as a foreland-propagating (west to east) wedge mostly during Cretaceous to Paleogene time, and included a western thrust system with aerially extensive thrust sheets that carried thick passive margin strata, and an eastern thrust system that carried thinner strata. Within the Wyoming salient of the Sevier belt, major thrust and fold traces display systematic map-view curvature about an average N–S structural trend, reflecting a component of primary curvature related to sedimentary prism architecture, followed by 60–80% vertical-axis rotation of thrust sheets related to curved fault slip and interaction with Laramide arches at the salient ends. Internal deformation in the western thrust sheets was limited within strong shallower levels, whereas deeper levels underwent shear and vertical flattening near a weak basal fault zone. Internal deformation in the eastern thrust sheets included widespread early layer-parallel shortening (LPS), followed by concentration of slip onto weak fault zones. Approximately 200 km of thin-skin shortening in the Sevier belt was transferred into lower crustal thickening and uplift of an orogenic plateau in the hinterland to the west. Synorogenic strata were deposited in an evolving foreland basin to the east that formed during flexural loading of thrust sheets and regional dynamic subsidence during subduction. Overall E-oriented shortening in the Sevier belt is interpreted to reflect increased gravitational potential energy and evolving topographic slopes from a hinterland plateau through a growing thrust wedge. Laramide basement-cored arches and intervening basins developed during later Cretaceous to Paleogene time, overlapping with younger stages of Sevier deformation. Arches and associated reverse faults display a wide range of trends within an overall NW–SE oriented, anastomosing network, partly reflecting primary basement heterogeneities. Limited vertical-axis rotations were localized along obliquely trending arch forelimbs and near arch intersections. Internal deformation in the foreland included limited LPS that refracted near variably trending arches. Laramide deformation was spatially and temporally correlated with a region of flat-slab subduction, recorded by changes in magmatic and subsidence patterns. Overall ENE-oriented shortening in the Laramide belt was at low angles to relative plate motion, likely reflecting increased plate coupling near a cratonic lithosphere keel. An integrated model for tectonic evolution of the Sevier and Laramide belts includes: influence of primary sedimentary architecture and basement weaknesses; enhanced plate coupling from increased overriding plate motion, fast convergence rates, and development of a flat-slab segment; linkage of upper crustal shortening in the Sevier belt with lower crustal thickening and uplift of a hinterland plateau; interaction between frontal thrusts in the Sevier belt and Laramide arches with differently oriented stress fields; concentrated slip along weak fault zones; redistribution of mass by erosion and deposition of synorogenic strata; and a switch to orogenic collapse during decreased convergence rates and slab removal. [ABSTRACT FROM AUTHOR]

Abstract: The Lang Shan, North-Central China, has experienced a complex Mesozoic to recent history of intraplate deformation and sedimentation. Well-exposed cross-cutting relationships document Jurassic right-lateral strike-slip faulting (transtension) followed by several tens of kilometers of Late Jurassic to Early Cretaceous north-northwest–south-southeast crustal shortening and development of an associated foreland basin. Since the Early Cretaceous, the south-central Lang Shan has undergone two phases of extension. The first, which occurred along north–south oriented structures, may represent collapse of an overthickened crust. The youngest deformation is represented by the active Cenozoic mountain-front normal fault system. This compound history may be the result of the complicated far-field effects of plate interactions combined with structural inheritance in a region adjacent to a rigid and undeformed crustal block, the Ordos block. [Copyright &y& Elsevier]