The Sichuan Basin is a prime gas-producing basin in China. Besides the giant Neoproterozoic Weiyuan gas field discovered in the central paleo-uplift, an extra giant gas reservoir in the Cambrian in this area has been confirmed in recent years. Although the lower Paleozoic in the southwest (Weiyuan area) is normally pressured, it is overpressured in the central area (Moxi–Gaoshiti area). Combined with the seal distribution, five pressure systems, including three overpressure systems, can be divided based on drill-stem test, mud weight, and sonic transit time data. Overpressures appear at depth interval of 1500 to 4900 m (4921 to 16,076 ft), approximately. Benefiting from the good sealing capacity of the gypsum in the Upper and Middle Triassic, high overpressure (pressure coefficient [r] > 2.0) has been preserved in the Lower Triassic, and the Upper Triassic and Cambrian are moderately overpressured (1.3 < r < 1.7). Mechanisms for various overpressure systems are different. Abnormally high sonic transit time in the Permian indicates disequilibrium compaction overpressure. The analyses of sonic transit time–effective stress suggest that disequilibrium compaction is the primary mechanism for the overpressure in the Upper Triassic Xujiahe Formation, but the Cambrian overpressure system is predominantly associated with fluid expansion, which mainly resulted from gas generation. Furthermore, we consider that the late thermal cracking of oil to gas is a key factor for gas and overpressure preservation in old strata. The high overpressure in the Lower Triassic marine carbonate rocks was caused by oil cracking and gypsum dehydration mechanisms. Combining the origin analysis with the burial and hydrocarbon generation histories, we constructed the Cambrian pore pressure evolution model, which is characterized by roughly normal pressure before 200 Ma, overpressuring from 200 to 90 Ma, and overpressure releasing since 90 Ma.

Cenozoic exhumation in the Tianshan is controlled by a complex interaction between tectonics and climate. However, the timing and magnitude of exhumation of the Tianshan and its contribution to climate change in Central Asia remains debated. In this study, we report new apatite fission track and (U‐Th)/He ages for granite samples from the roof of the South Tianshan that are significantly younger than those published for other parts of the South Tianshan. Inverse and forward modeling reveals two phases of accelerated cooling at 10∼6 Ma and since ∼3 Ma, which can be linked to (1) the reactivation of strike‐slip faults and hot asthenospheric upwelling during India‐Eurasia convergence and (2) the interplay between tectonics and glaciation, respectively. The 10∼6 Ma exhumation phase further corresponds to the timing of climate change, suggesting that this exhumation phase significantly contributed to the enhanced aridification of the Tarim Basin.

The formation and evolution of a rift basin is the shallow response of deep geodynamic processes. The Bohai Bay Basin is at the center of lithosphere destruction and thinning in the eastern North China Craton (NCC). In this article, the Meso-Cenozoic thermal lithospheric thickness of the Bohai Bay Basin was calculated by reconstructing the thermal history of the sedimentary basin using apatite fission track and vitrinite reflectance data. The Meso-Cenozoic thermal modeling results show that the basin experienced four evolutionary stages with two heat flow peaks in the late Early Cretaceous and in the Middle to Late Paleogene, which had heat flow values of 82–86 and 81–88 mW/m², respectively. Accordingly, the thermal lithospheric thicknesses of the basin, calculated from the thermal histories, experienced two thinning stages in the Cretaceous and the Paleogene. The lithosphere began with an initial thickness of 150 km in the Early Mesozoic and was thinned to approximately 51–61 km in the late Early Cretaceous. The thickness then increased to approximately 80–90 km at the end of the Cretaceous. A second thinning phase occurred in the Middle to Late Paleogene, resulting in a thickness of only 43–55 km. The lithosphere thickened thereafter, and the NCC now has a thermal lithosphere of 75–97 km. The lithospheric thinning in the Cenozoic was dominated by extension rather than thermal erosion. At the same time, there existed some differences in the thermal evolution and lithospheric thinning evolution among different sub-basins, but the time of peak heat flow and peak lithosphere thinning in the Cenozoic is consistent with the migration of the depocenter of the basin. Therefore, the thermal history of sedimentary basins may provide continuous temporal and spatial evidence to reveal deep geodynamic processes. Our research provides new geothermal evidence for the lithospheric thinning of the NCC.

The Tarim Basin is one of the most important hydrocabon-bearing evaporite basins in China. Four salt-bearing sequences, the Middle and Lower Cambrian, the Mississippian, the Paleogene, and the Neogene, have various thickness and areal distribution. They are important detachment layers and intensely affect the structural deformation in the basin. The Kuqa depression is a subordinate structural unit with abundant salt structures in the Tarim Basin. Salt overthrusts, salt pillows, salt anticlines, salt diapirs, and salt-withdrawal basins are predominant in the depression. Contraction that resulted from orogeny played a key function on the formation of salt structures. Growth strata reveal that intense salt structural deformation in the Kuqa depression occurred during the Himalayan movement from Oligocene to Holocene, with early structural deformation in the north and late deformation in the south. Growth sequences also record at least two phases of salt tectonism. In the Yingmaili, Tahe, and Tazhong areas, low-amplitude salt pillows are the most common salt structures, and these structures are commonly accompanied by thrust faults. The faulting and uplifting of basement blocks controlled the location of salt structures. The differences in the geometries of salt structures in different regions show that the thickness of the salt sequences has an important influence on the development of salt-cored detachment folds and related thrust faults in the Tarim Basin. Salt sequences and salt structures in the Tarim Basin are closely linked to hydrocarbon accumulations. Oil and gas fields have been discovered in the subsalt, intrasalt, and suprasalt strata. Salt deformation has created numerous potential traps, and salt sequences have provided a good seal for the preservation of hydrocarbon accumulations. Large- and small-scale faults related with salt structures have also given favorable migration pathways for oil and gas. When interpreting seismic profiles, special attention needs to be paid to the clastic and carbonate interbeds within the salt sequences because they may lead to incorrect structural interpretation. In the Tarim Basin, the subsalt anticlinal traps are good targets for hydrocarbon exploration.

The Bohai Offshore Area is located in the northeastern marine area of the Bohai Bay Basin in northern China. It is one of the most productive petroleum basins in China. In this study, thermal gradient and heat flow distribution results for the Bohai Offshore Area (Bohai Subbasin) were obtained based on new oil-testing temperatures, drill-stem test temperatures (DSTs), bottom-hole temperatures (BHTs) and documented thermal conductivity data. The average geothermal gradient is 32.0±4.6°C/km for the entire offshore area. Heat flow in the Bohai Subbasin ranges from 33.5 mW/m² to 84.0 mW/m², with an average value of 60.8±8.7mW/m². Thermal gradient evolutions of several sags in the Bohai Subbasin were obtained using constraints for single well modeling from vitrinite reflectance ( R_o) and apatite fissin track (AFT) data. Modeling results show that there were different thermal histories for different parts of the subbasin. Generally, the thermal gradient gradually decreased with geological evolution. The thermal gradient was 57∼53°C/km in the Paleocene epoch and 53∼43°C/km during the deposition period of the Shahejie Formation (e.g., Eocene epoch). This value slowly decreased after the Oligocene (38∼43°C/km). It was 38∼34°C/km in the Miocene, and it is 32°C/km at present-day. This thermal gradient evolution relates well to activities in the Tanlu Fault Zone and to tectonic subsidence. The first episode of the syn-rift initial subsidence of the basin shows a higher thermal gradient during the Paleocene∼Eocene epochs. The second episode of thermal subsidence corresponds to a lower thermal gradient after the Oligocene epoch. The geothermal regime of the Bohai Offshore region will provide some useful data to study regional tectonic characteristics of the basin and the evolution of hydrocarbon source rocks.