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Sicily is a thick orogenic wedge formed by (1) the foreland (African) and its Sicilian orogen and (2) the thick-skinned, Calabrian-Peloritani wedge. The crust under central Sicily, from the Tyrrhenian margin to the coastline of the Sicily Channel, has been investigated by the multidisciplinary (SI.RI.PRO.) research project. The project dealt with the nature and thickness of the crust and depth and geometry of the Moho, which is essential in formulating subduction models and improving the knowledge of African and Tyrrhenian-European lithospheres. The results resolve features such as (1) the main orogenic wedge, (2) the very steep, NW-SE-trending regional monocline suggesting inflection of the foreland crust, (3) the deep Caltanissetta synform imaged, for the first time, to about 25 km, and (4) the top of the crystalline basement and the inferred crust-mantle boundary. The SI.RI.PRO. transect confirmed that the NNW-dipping, autochthonous Iblean platform of SE Sicily and its basement extends all the way into central Sicily. Further NW, towards the NNW end of the transect, a large uplift involves the Iblean platform and its underlying basement. The associated gravity anomaly is interpreted as the southern wedge edge of the Tyrrhenian mantle that splits the subducting Iblean-Pelagian (African) continental slab from an overlying synformal stack of allochthonous thrust sheets.

Orogenic processes worldwide have been attributed to various deformation mechanisms. However, the significance of lithospheric folding in these processes has often been overlooked and underestimated. Within the South China Block (SCB), a region marked by notable temporal and spatial variability in intracontinental deformation, the emergence of fold-and-thrust belts during the Paleozoic and Mesozoic periods has captured a scientific interest. The mechanisms governing the genesis of these belts remain a subject of debate, with no discernible subduction interface accounting for the extensive-scale fold-thrust deformation. Moreover, the SCB presents a substantial variation in lithospheric thickness, exceeding 100 km, offering a plausible mechanism for lithospheric folding. To interrogate this mechanism, we conducted lithospheric compression simulations via two-dimensional finite element methods, incorporating variable viscosity both laterally and vertically within the SCB. Our models elucidate that disparities in lithospheric strength beget distinctive deformational manifestation within the SCB. We observe that a weaker lithosphere tends to uplift, whereas a stronger lithosphere tends to subside during compression. Lithospheric strength also influences the Xuefengshan uplift and the spatial distribution of deformational features. In addition, lithospheric folding can account for crustal shortening and the presence of deep anomaly structures. A compelling correlation emerges between lithospheric folding and fluctuations in Moho depth and lithospheric thickness, suggesting its potential influence over the prolonged topographical evolution and shifts in depositional environments within the SCB. This study sheds new light on the role of lithospheric folding in the complex geodynamic history of the SCB and highlights its importance in understanding the broader context of orogenic processes worldwide.

The Pamir salient accommodates a great amount of Cenozoic India-Eurasia convergence in the forms of thrusting, strike-slip faulting, extension, and gneiss dome formation. It thus becomes a key location for exploring the orogenic tectonic evolution. Here, we focus on the Eastern Pamir where extensional deformation dominates during the late Cenozoic. We conducted low-temperature thermochronological dating on bedrock samples collected from the footwall of the Kongur Shan normal fault together with inversion of the longitudinal river profile of the Gez River. Our new zircon and apatite (U-Th)/He (ZHe and AHe) data reveal young ages in proximity to the normal fault and older ages adjacent to the western Tarim Basin. By inverting the Gez River profile together with published and new thermochronological ages, we obtained a sustained uplift rate of ∼3 mm/yr in the Kongur Shan dome since ∼8 Ma, contrasting with no significant uplift to the east of the dome before the Pliocene. This uplift pattern can be interpreted as a result of the upward extrusion of crust materials along a flat-ramp-flat thrust fault at depth under the context of convergence.

Recent development near Bryce Canyon National Park, Utah, could affect local groundwater usage, availability, and dependent resources. The National Park Service and Utah Geological Survey conducted a geophysical study targeting the Rubys Inn thrust fault. This fault lies between commonly targeted aquifers in Emery Valley and groundwater flow systems of the Paunsaugunt Plateau, which support springs and dependent ecosystems. Fault zone geometry and internal structure are complex, resulting in a heterogeneous permeability distribution that affects groundwater flow. The influence of fault zones on groundwater flow parallel and perpendicular to their planes is difficult to predict. Geophysical imaging can yield important information about subsurface fault geometry. We utilized electrical resistivity tomography (ERT) surveys to investigate the influence of the Rubys Inn fault on groundwater occurrence and movement along the southeast boundary of Emery Valley. We collected ERT data along three transects orthogonal to the mapped fault strike in May and September 2022. Where available, we used water-level and lithologic data to constrain ERT inversion model interpretations. The inversion models illustrate the complexity and variability of the Rubys Inn fault within a short distance along strike. Where the fault is concealed, results indicate that the actual and mapped locations differ by 70-100 m along the transects. Groundwater is well constrained in the hanging wall, but poorly constrained in the footwall, and some seasonal variation is discernible. Variable stratigraphy and structure are apparent in all transects. This study enables strategic placement of test wells that will further establish the influence of the Rubys Inn fault on the occurrence and movement of groundwater in and adjacent to the fault zone. The study demonstrates that ERT is a cost-effective and noninvasive tool for detecting the precise surface location and delineating subsurface fault geometry in otherwise data-poor areas with sensitive ecological or archaeological resources.

Taishan Mountain in the eastern China is a normal-fault-controlled range that formed during the Meso-Cenozoic, in response to large-scale extension and lithospheric thinning of the North China Craton. However, constraints on the timing of the polyphase extensional events which formed the Taishan edifice remain poorly resolved, hindering a detailed understanding of the landscape evolution of this prominent mountain. Here, we conducted apatite (U-Th)/He dating on sixteen samples from three profiles perpendicular in the Taishan Mountain, with a major view to control structures in Taishan Mountain and to resolve the Meso-Cenozoic landscape evolution. The newly determined apatite (U-Th)/He ages show a wide variation range of ∼113 to 30 Ma, indicating a slow and protracted cooling history. The inverse thermal history modeling results reveal two pulses of enhanced cooling at ∼80 to 60 and 55 to 50 Ma, which we interpret as exhumation related to normal fault activity. Furthermore, one-dimensional modeling indicates that the magnitude of tectonic exhumation is constrained at ≥15 m/Myr across the Yunbuqiao, Zhongtianmen, and Taishan Piedmont faults. Integrating this study and published studies, we suggest that Taishan Mountain underwent four-stage evolution since 100 Ma: (1) the whole Taishan Mountain commenced a continuous and slow exhumation under a weaker tensional environment at ∼100 to 80 Ma, (2) the joint growth and interactions within a normal fault system resulted in rapid uplift and promoted the formation of the Proto-Taishan Mountain at ∼80 to 60 Ma, (3) the Taishan Mountain underwent exhumation at ∼55 to 50 Ma, interpreted as a tectonic response to the Taishan Piedmont Fault, and (4) the last stage (∼50 to 0 Ma), the Taishan Mountain experienced protracted exhumation related to normal faulting until now. We attribute the extensive normal faulting to the subduction and slab rollback of the Izanagi-Pacific Plates, which shaped the present-day geomorphology of Taishan Mountain.

The evolution of the Alpine Tethys margins during the beginning of the African-Eurasian convergence was little studied compared to their evolution during the post-Pangea rifting and oceanic expansion, i.e., from the Early Jurassic to the early Late Cretaceous. The present work firstly aims to make up for this shortcoming in the case of the distal European margin of the Alpine Tethys, namely the Briançonnais domain of the Western Alps. We show that this margin was affected by strong post-rifting extension mainly in Late Cretaceous-Paleocene times and propose to make it the type of the (rare) \"Late Extension Passive Margins\". Remarkably, this extension shortly preceded Lutetian times, when Briançonnais margin encroached the SE-dipping subduction zone under the Adria microplate. Secondly, we assess the post-rifting evolution of the north-Tethyan paleomargin in the Maghrebides transects, i.e., south-west of the Briançonnais transect along the same European-Iberian paleomargin. For this purpose, we consider the Triassic-Eocene series of the \"Dorsale Calcaire\" in the Alkapeca Blocks located along southeastern Iberia until the Eocene then transported onto the North African margin. Examination of the literature shows that the Tethyan margin of the Alboran block was strongly affected by normal faulting as early as Late Jurassic-Early Cretaceous times whereas post-rifting extension of the Kabylian blocks mainly occurred in the Late Cretaceous-Paleocene like in the Briançonnais. We propose that post-rifting extension of the Alboran block southern margin resulted from the sinistral movement of Africa relative to Iberia while the later extension of the Kabylian blocks can be related to the further convergence kinematics. Subduction of the Ligurian-Maghrebian slab under the North African margin would have occurred at that time in the southward continuation of the Alpine subduction. The overriding Adria and North African margins did not experience significant compression at that time. During the Eocene, a subduction polarity reversal occurred, which was associated with the relocation of the subduction zone along the Alkapeca block. This was the beginning of the Apenninic subduction, which triggered the back-arc opening of the Mediterranean basins.

A conodont-graptolite biostratigraphic study was carried out on the top strata of the San Juan, Las Chacritas and Las Aguaditas formations in the La Trampa Range, Precordillera of San Juan in western Argentina. Significant conodont records in the San Juan and Las Chacritas formations allow for the recognition of the Yangtzeplacognathus crassus, Eoplacognathus pseudoplanus (Microzarkodina hagetiana and M. ozarkodella subzones) and Eoplacognathus suecicus zones of Darriwilian age. Index species and co-occurrences of graptolites and conodonts were recorded in the Las Aguaditas Formation allowing the identification of the Nemagraptus gracilis and the Pygodus anserinus zones, which represent the Sandbian Stage. These data indicate a hiatus between the Las Chacritas and the Las Aguaditas formations, corresponding to the Pygodus serra Zone and the Pterograptus elegans and Hustedograptus teretiusculus zones (upper Darriwilian). A total of 7287 identifiable conodont elements were recorded from the study section. The species frequency registered for each zone shows that Periodon and Paroistodus are the most abundant taxa, which are indicative of open marine environments. The records of particular conodont taxa, such as Histiodella, Periodon, Microzarkodina, Eoplacognathus and Baltoniodus, allow a precise global correlation with other regions such as south-central China, Baltoscandia, North America, Great Britain, Southern Australia and New Zealand. The graptolite fauna identified here are recognized worldwide in equivalent strata in the Baltic region, Great Britain, North America, China, southern Australia and New Zealand. The presence of graptolites in the ribbon limestones of the Las Chacritas Formation is documented for the first time.

Under the International Philippine Sea Geotraverse Project, research has been conducted on a deep geological and geophysical section of the tectonosphere, which includes the lithosphere and the asthenosphere, where the majority of Earth’s tectonic and magmatic processes occur. The present paper focuses on the Mariana region that is home to most such processes. The study attempts to model the deep structure of the Mariana Island Arc along the Philippine Sea Geotraverse.

The North Huicheng Basin strike-slip fault system is on the northeastern frontier of the Tibetan Plateau and separates the West and East Qinling differential orogeny. However, the deformation mechanism of this strike-slip fault system and its exact tectonic significance are unclear. Here, we carried out systematic field structural analysis, physical analog modeling, and multiproxy geochronological dating to address these issues. The field structural analysis indicates that the North Huicheng Basin strike-slip fault system was induced from the plate-like movement of the West and East Qinling Orogens, which underwent multiple left-lateral strike-slip faulting and controlled salient and recessed structures. The scaled physical analog experiment results confirm this hypothesis and reveal the primary spatial-temporal deformational kinematic process. Combined with published works, multiproxy geochronological dating (zircon U-Pb age of 213 Ma, biotite 40Ar/39Ar age of 203 Ma, and apatite fission-track age of 56 Ma) outlines the main thermal history of the hanging wall. Based on the above facts, the integrated research suggests that multistage strike-slip faulting played a significant role in the main tectonic events, that is, Late Triassic magmatic emplacement, Jurassic/Cretaceous local pull-apart, and Cenozoic rapid exhumation driven by Tibetan Plateau growth.

Despite playing a fundamental role in all models of Himalayan tectonics, minimal data constraining the structural evolution, metamorphic history, and offset magnitude of the South Tibetan detachment system (STDS) are available. Here, we integrate petrofabric, finite strain, and kinematic data with metamorphic and deformation temperatures to generate a structural model for the STDS in northwestern Bhutan. We divide the STDS into an ∼2-km-thick lower level that accommodated ∼6-13 km of thinning via ≥30-76 km of simple shear-dominant displacement within Greater Himalayan rocks, and an ∼3-km-thick upper level that accommodated ≥21 km of displacement via an upward decrease (from 44% to 2%) in transport-parallel lengthening within Tethyan Himalayan rocks. Peak metamorphic temperatures in the lower level are ∼650-750 °C, and two distinct intervals of telescoped isotherms in the upper level define a cumulative upward decrease from ∼700 to ∼325 °C. These intervals are separated by an abrupt upward increase from ∼450 to ∼620 °C, which we interpret as the result of post-STDS thrust repetition. Above the upper telescoped interval, temperatures gradually decrease upward from ∼325 to ∼250 °C through a 7-km-thick section of overlying Tethyan Himalayan rocks. Telescoped isotherms lie entirely above the high-strain lower level of the STDS zone, which we attribute to progressive elevation of isotherms during protracted intrusion of granite sills. This study demonstrates the utility of using gradients in fabric intensity and thin section-scale finite strain to delineate shear zone boundaries when field criteria for delineating strain gradients are not apparent.