A Structural Interpretation Model and Restoration of the Mesozoic Proto‐basin for the Kuqa Depression, Tarim Basin

Abstract

A thrust‐fold belt consisting of a series of thrusts and buckling folds developed in the Mesozoic and Cenozoic strata within the Kuqa Depression, Tarim Basin. In this study, a structural interpretation model of the Kuqa Depression is established and the Mesozoic proto‐basin is reconstructed on the basis of outcrop geology along the basin margin, seismic, well‐log and CEMP data. The model is called ‘delaminate contractional deformation’, which emphasizes the decoupling between the Cenozoic, Mesozoic, pre‐Mesozoic and the basin‐basement within the Kuqa Depression, but there is no unified detachment. The model has a shortening amount ranging from 12 km to 16 km and the depth involved in contractional deformation ranges from 21 km to 28 km. A prototype of the Mesozoic basin reconstructed by interpretation model is a sub‐basin superposed on the transitional zone between the uplift at the northern edge of the Tarim Craton and the southern Tianshan orogenic wedge formed in the Hercynian orogeny. Lithospheric thermal and crustal isostatic activity after the Hercynian orogeny maybe the controlling dynamic factors of basin subsidence during the Mesozoic and early Cenozoic, the difference in rock mechanical properties between different levels, craton and orogenic wedge being the major cause of the ‘delaminate contractional deformation’ during the Himalayan orogeny.

Diagenesis of the Paleogene Sandstones in the DN2 Gas Field, Kuqa Foreland Basin and its Link to Tectonics

“…During the end of the late Paleozoic Era (from the late Carboniferous to the early Permian) multiple blocks and arcs collided, resulting in the closure of the South Tianshan Ocean (Xiao et al, 2004;Charvet et al, 2011;Alexeiev et al, 2015); Kuqa therefore entered an intracontinental tectonic evolution stage. This region was considered to be tectonically stable during the Triassic to Paleogene periods, possessing the characteristics of a depression basin without obvious faulting (Jia, 2013;Li Y et al, 2017;Qi et al, 2023). Since the beginning of the Neogene, the KFB began to develop as a foreland basin while India collided with the Eurasian Plate (Lu et al, 2000).…”

Evolution of the foreland basins on either side of the Tian Shan and implications for lithospheric architecture

“…The ancestral Tian Shan orogen formed during the Paleozoic through the accretion of several island arcs and collision of continental blocks (Burtman, 1975;Windley et al, 1990;Xiao et al, 2013), with large-scale dextral strike-slip occurring in the late Carboniferous-Permian (Bazhenov et al, 1999 (Lu et al, 1994;Jia et al, 1997;Wang et al, 2001a;Qi et al, 2013;Li et al, 2016b). The NTFB in Tian Shan's south piedmont has a maximum thickness of ~7 km of Cenozoic foreland strata, while the SJFB has a maximum thickness of ~5 km (Fig.…”

“…2): (1) The unidirectional underthrusting of the Tarim lithosphere beneath the Tian Shan (Zhao et al, 2003;Steffen et al, 2011;Gilligan et al, 2014); (2) the bidirectional underthrusting of the Tarim and Junggar lithospheres (Li et al, 2016a;Lü et al, 2019); and (3) mantle upwelling caused by small-scale mantle convection in the upper mantle or the delamination of the thickened lithosphere (Roecker et al, 1993;Lei and Zhao, 2007;Li et al, 2009). The topographic uplift of the modern Tian Shan induced flexural subsidence in the Northern Tarim and the Southern Junggar blocks, forming a typical intra-continental orogenic belt-foreland basin system (Lu et al, 1994;Jia et al, 1997;Wang et al, 2001a;Qi et al, 2013).…”

Structural Variation between the Western and Eastern Kuqa Fold‐and‐thrust Belt, China: Insights from Seismic Interpretation and Analog Modeling

“…The apparent structural variation in the Kuqa fold-andthrust belt has drawn considerable attention in recent years. The varied structural geometry and salt tectonics have been described intensively based on the seismic interpretations and synthetic models (Chen et al, 2004;Tang et al, 2004a, b;Jin et al, 2008;Yu et al, 2008Yu et al, , 2014Qi et al, 2009Qi et al, , 2023Guan et al, 2010;Wang et al, 2011). Different factors, including the syntectonic sedimentation, structural inheritance, detachment distribution and rheology, have been fully discussed in nature and evaluated using analog modeling and numerical simulation (Izquierdo-Llavall et al, 2018;Neng et al, 2018;Pla et al, 2019;Wang et al, 2020;Long et al, 2021).…”