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The Weiningbeishan fold‐thrust belt (WFTB), located in the transitional zone of the Tibetan Plateau, Alxa Block and Ordos Basin, is an ancient intracontinental orogenic belt. In this article, structural analysis is conducted to more finely reveal differential deformation between the Devonian and Carboniferous strata in the WFTB. We found that the E–W‐trending open folds are mainly developed in the Upper Devonian Zhongning Formation (D3z), while the E–W‐trending close and tight folds are mainly developed in the Carboniferous strata. The N–S minimum shortening strain of the bottom boundary of Member 2 of the Upper Devonian Zhongning Formation (D3z2) is 21.1%, whereas the N–S minimum shortening strain of the bottom boundary of Member 2 of the Upper Carboniferous Danliangshan Formation (C2d2) is 64.1%. We propose that the E–W‐trending open folds in the Upper Devonian Zhongning Formation (D3z) and E–W‐trending close and tight folds in the Carboniferous strata were formed under the N–S compression during the Middle–Late Triassic. The Zhangyigou and Laoyagou faults are the main tear faults to accommodate differential displacement on the surface between the Upper Devonian Zhongning Formation (D3z) in the east and Carboniferous strata in the middle, which change into a décollement fault in the deep part of the Dafosigou fold area in the middle to accommodate differential deformation between the deep Upper Devonian Zhongning Formation (D3z) and Carboniferous strata. This study enables us to better understand the Mesozoic intracontinental deformation in response to far‐field plate‐boundary convergence in NW China. [ABSTRACT FROM AUTHOR]

The Tianshan range, a Paleozoic orogenic belt in Central Asia, has undergone multiple phases of tectonic activities characterized by the N–S compression after the early Mesozoic, including the far‐field effects of the Cenozoic Indian–Asian collision. However, there are limited reports on the tectonic deformation and initiation of Triassic intracontinental deformation in the Tianshan range. Understanding this structural context is crucial for interpreting the early intracontinental deformation history of the Eurasian continent during the early Mesozoic. Growth strata and syn‐tectonic sediments provide a rich source of information on tectonic activities and have been extensively used in the studies of orogenic belts. Based on detail fieldwork conducted in this study, the middle–late Triassic Kelamayi Formation of the northern Kuqa Depression in the southern Tianshan fold‐thrust belt has been identified as the typical syn‐tectonic growth strata. The youngest detrital zircon component in two lithic sandstone samples from the bottom and top of the Kelamayi growth strata yielded U‐Pb ages of 223.4 ± 3.1 and 215.5 ± 2.9 Ma, respectively, indicating that the maximum depositional age of the bottom and top of the Kelamayi growth strata is 226–220 and 218–212 Ma. The geochronological distribution of detrital samples from the Early–Middle Triassic and Late Triassic revealed abrupt changes, suggesting a new source supply resulting from tectonic activation in the Tianshan range. The coupling relationship between the syn‐tectonic sedimentation of the Kelamayi Formation and the South Tianshan fold‐thrust system provides robust evidence that the Triassic intracontinental deformation of the South Tianshan range began at approximately 226–220 Ma (during the Late Triassic) and ended at approximately 218–212 Ma. These findings provide crucial constraints for understanding the intraplate deformation in the Tianshan range during the Triassic. [ABSTRACT FROM AUTHOR]

This is a review of the formation and tectonic evolution of the continental Asia in Phanerozoic. The continental Asia has formed on the bases of some pre‐Cambrian cratons, such as the Siberia, India, Arabia, North China, Tarim, South China, and Indochina, through multi‐stage plate convergence and collisional collages in Phanerozoic. The north‐central Asia had experienced the expansion and subduction of the Paleo‐Asian Ocean (PAO) in the early Paleozoic and the closure of the PAO in the late Paleozoic and early Mesozoic, forming the PAO regime and Central Asian orogenic belt (CAOB). In the core of the CAOB, the Mongol‐Okhotsk Ocean (MOO) opened with limited expansion in the Early Permian and finally closed in the Late Jurassic–Early Cretaceous. The south‐central Asia had experienced mainly multi‐stage oceanic opening, subduction and collision evolution in the Tethys Ocean, forming the Tethys regime and Himalaya‐Tibetan orogenic belt. In eastern Asia, the plate subduction and continental margin orogeny on western margin of the Pacific Ocean, forms the West Pacific regime and West Pacific orogenic belt. The PAO, Tethys, and West Pacific regimes, together with Precambrian cratons among or surrounding them, made up the major tectonic and dynamic systems of the continental Asia in Phanerozoic. Major tectonic events, such as the Early Paleozoic Qilian, Uralian, and Dunhuang orogeneses, the late Paleozoic East Junggar, Tianshan and West Junggar orogeneses, the Middle to Late Permian Ailaoshan orogeny and North‐South Lhasa collision, the early Mesozoic Indochina‐South China and North‐South China collisions, the late Mesozoic Mongolia‐Okhotsk orogeny, Lhasa‐Qiangtang collision, and intra‐continental Yanshanian orogeny, and the Cenozoic Indo‐Asian, Arab‐Asian, and West Pacific margin collisions, constrained the formation and evolution of the continental Asia. The complex dynamic systems have left large number of deformation features, such as large‐scale strike‐slip faults, thrust‐fold systems and extensional detachments on the continental Asia. Based on past tectonics, a future supercontinent, the Ameurasia, is prospected for the development of the Asia in ca. 250 Myr. [ABSTRACT FROM AUTHOR]

[Display omitted] • Field mapping indicated the geometry of nappe structure in the northern Alxa region, NW China. • The crustal shortening of the southern CAOB was established during the Late Triassic. • Two large-scale strike-slip systems dominated the Late Triassic tectonic framework of the southern CAOB. The Central Asian Orogenic Belt (CAOB) experienced multistage intracontinental deformation during the Mesozoic and Cenozoic. Recent studies have shown that a large-scale nappe structure developed in the northern Alxa region. Here, we present new field investigations, structural analysis, and a new balanced cross-section in order to better constrain its geometries, displacement and activity time. Three nappe stacks with distinctive lithostratigraphic assemblies, structural characteristics and displacement were recognized: (1) the structural highest China-Mongolia boundary nappe preserving as klippen has a minimum displacement of ∼ 65 km; (2) the Yagan thrust sheet is dominated by an E–W-trending syncline and has a minimum displacement of ∼ 30 km; and (3) the structural lowest Gashunzhadegai thrust sheet is characterized by S-vergent folds and imbricated faults and has a minimum displacement of ∼ 14 km (30 %). The youngest strata involved in the nappe structure and the cross-cutting relationships indicated that the nappe structure formed during the Late Triassic (230–215 Ma). Regionally, it occurred later than the final closure of the Paleo-Asian Ocean and marked the beginning of the intracontinental evolution of the southern CAOB. Integrating previous structural, thermochronological and sedimentological data with our studies, we suggested that the Late Triassic tectonic framework of the middle segment of the southern CAOB was dominated by two large-scale en echelon strike-slip systems. In addition, the driving force for the Late Triassic intracontinental deformation was most likely to be the collision of the Bayan Har Terrane and Yangtz Craton with the Eurasian continent. [ABSTRACT FROM AUTHOR]

The E–W-trending Qinling Orogen lies in the transitional zone between the northeastern extent of the Tibetan Plateau and the lower-elevation portion of the continent. This region is suggested to have accommodated flow of the low-viscosity lower crust from the Tibetan Plateau northward around the Sichuan Basin during the Cenozoic Himalayan–Tibetan orogeny. To test this model, we combined field geologic mapping, balanced cross-section construction, thermochronology, and geophysical interpretation to constrain the history of crustal thickening from the Mesozoic to the present. In this study, we obtained new thermochronological data from four samples, which yielded 40Ar/39Ar ages of ∼194 Ma for hornblende and 208-151 Ma for biotite and apatite fission track ages of 69-42 Ma. The new thermochronological data and field mapping demonstrate that most shortening structures initially formed in the Mesozoic and underwent minor structural overprinting in the Cenozoic. Systematic structural analyses and restoration of balanced cross-sections demonstrate that the Qinling Orogen was shortened by a minimum of 35% strain (80 km shortening magnitude) after the Mesozoic Paleotethys Ocean closure and continental collision. The crust thickened substantially to >60 km, and the thermochronological data demonstrate that erosion and denudation were minor, such that the crust would have remained thick into the Cenozoic. An additional balanced cross-section across Cenozoic strata suggests >11% Cenozoic shortening, and the observed shortening alone is enough to thicken the crust to the presently observed ∼40–45 km. Therefore, we argue that lower crustal flow is not needed to account for the crustal thickness of the Qinling Orogen and that the data do not support the occurrence of processes associated with lower crustal flow beneath the Qinling Orogen. [Display omitted] [ABSTRACT FROM AUTHOR]