The lithospheric "de-rooting" of the Sulu-Dabie Orogen (SDO) is an important tectonic mechanism for post-orogenic tectono-magmatism, which influenced the sedimentation, evolution, and development of oil-gas accumulation in the Hefei Basin (HB). Combined with seismic, geological, and sedimentary data of the HB and the SDO, this paper studies the coupling of the HB and the SDO since the Late Mesozoic. While the North China Block (NCB) indented south-eastwards under the Greater South China Block (GSCB) since the Mesozoic, the SDO underwent three intense tectonic stages, i.e., subduction, exhumation, and uplift. The upwelling of deep mantle material causes the exhumation of the ultrahigh-pressure metamorphic (UHPM) rocks to the upper crust or surface, forming the UHPM. Influenced by the indentation of the NCB, the "de-rooting" of the SDO lithosphere, caused the delamination and thinning of the lithosphere, accompanied by the continuous flexural subsidence in the HB. The basin underwent at least four stages of tectonic evolution, involving sequentially: the flexural basin, the foreland basin, the strike-slip-related basin, and the faulted graben development periods. The tectonic evolution of the HB was closely coupled with the SDO orogeny. The "de-rooting" of the SDO lithosphere resulted in a strong uplift and erosion of the orogen, providing abundant source of material for the HB and causing the successively northwards migration of basin depocenters at its early stage. Finally, influenced by the subduction retreat of the (Palaeo-) Pacific Plate and the strike-slip movement of the Tanlu Fault, the depocenters migrated to the east.
The coupling mechanism of the Tianshan Orogenic Belt (TOB) and the basins on its sides (Junggar, Turpan–Hami, Tarim, Yili, etc.) since the Late Mesozoic was complex and multi‐levelled. Based on gravity, magnetism, Moho discontinuity, and lithospheric velocity structure of the TOB, together with the structural and sedimentary data of the basins, a model is proposed to reflect the influence of the basin–orogen coupling on the regional source–sink processes of sandstone‐type uranium mineralization since the Late Mesozoic. Generally, there are four main stages of tectonic movements that have changed the coupling mechanism of basin and orogeny: including the Early Yanshanian Movement, the Late Yanshanian Movement, the Middle Himalayan Movement, and the Late Himalayan Movement. These four movements together controlled the mineralization of the sandstone‐type uranium deposits in the TOB together. The mineralization of sandstone‐type uranium deposits in the TOB can be divided into three metallogenic stages: the ore‐bearing formation stage (T‐J2), the tectonic reversal‐related metallogenic stage (J3‐N1), and the epigenetic regenerating ore‐preserving stage (N2‐Q). The tectonic reversal‐related metallogenic stage can be subsequently divided into three sub‐stages: the pre‐metallogenic stage (J3), the sub‐metallogenic stage (K), and the main metallogenic stage (E‐N1). The associated uplift led to the deformation of the mineralized strata in the basins, while the reducing agent migration along faults enhanced the reduction environment within the strata, which affected the enrichment and distribution of the uranium mineralization in the strata. Meanwhile, the recharge and the change of flow state of groundwater also contributed to the later transformation and mineralization. The intra‐continental subduction caused deep lithospheric buckling and depression in the TOB, accompanied by local‐scale mantle convection, which accounts for both tectonic and geodynamic settings for the regional basin–orogen coupling mechanism. In addition, the far‐field effect of the India–Eurasian collision also provided the driving force for the sandstone‐type uranium mineralization in the TOB.
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