Understanding the timing and magnitude of deformation in the Tangula Range is crucial for elucidating the topographic growth of central Tibet. The Yanshiping region, located in the central Tangula Range, comprises Permian to Miocene sedimentary rocks that record the Tangula Range's deformational history since the Mesozoic. Our study presents new geological maps, balanced cross-sections, and low-temperature thermochronology results, shedding light on the deformational history of the Yanshiping region. The balanced cross-section reveals a north-verging fold-thrust belt accommodating at least 90 km of crustal shortening (>49 %) post-Jurassic deposition. Sedimentological and thermochronological data suggest substantial crustal shortening occurred at 60-35 Ma, likely driven by the India-Asia collision and related continental subduction. Integrating our results with previous studies, we infer that central Tibet's topographic evolution included a broad Central Tibetan Valley during similar to 96-60 Ma and a narrower valley during similar to 60-35 Ma.

The discovery of extensive layered witherite (BaCO3) deposits in the Early Cambrian strata in South China offers valuable insights into the unique paleo-marine environment of this region. Based on stratigraphy, petrography, geochemistry, fluid inclusions, and pervious published multi-isotope geochemical analysis, we aim to explore the distinct genesis mechanism of the witherite deposits in the Chengkou area of South China and unveil the specific paleo-marine environment during their formation. This study concludes that the wide 87Sr/86Sr ratios (0.708266 to 0.708504) of witherite and barytocalcite (BaCa(CO3)2) support the seawater-derived barium. Negative δ13C values (−15.6 to −12.5‰) indicate the involvement of organic matter during the formation of witherite. The complex vapor-phase (including CH4, H2S, etc.) and HS−-containing liquid-phase compositions in the primary liquid–vapor inclusions of the witherite and barytocalcite imply that the two minerals are formed in sulfur-rich euxinic seawater. The broad homogenization temperatures are generated by thermal re-equilibration of the inclusions, rather than the actual temperatures of the trapped fluids. The salinity range of fluid inclusions in the Bashan witherite deposit (0.2 to 16.2 wt.%) records mixing between moderate-salinity basinal-derived fluids and low-salinity seawater-sourced fluids. We propose that the formation of Chengkou witherite deposits is linked to a sulfate-limited euxinic seawater environment, highlighting the spatiotemporal heterogeneity in Early Cambrian paleo-oceanic sulfate concentrations.

The black rock series in the Qiongzhusi Formation contains important geochemical information about the early Cambrian tectonic and ecological environment of the southwestern Yangtze Block. In this paper, major, trace, and rare earth element data are presented in an attempt to reveal the sediment source during the deposition of the early Cambrian Qiongzhusi Formation and to reconstruct the sedimentary tectonic environment and weathering intensity during that time. The basin primarily received continental clastic material with neutral-acidic igneous rocks from a stable source and with a moderate level of maturity during the depositional period of the Qiongzhusi Formation. Furthermore, the strata were weakly influenced by submarine hydrothermal fluids during diagenesis. The reconstruction of the sedimentary environment and weathering intensity shows that P2O5 enrichment and water body stratification occurred due to the effects of upwelling ocean currents during the depositional period of the Qiongzhusi Formation. The combination of upwelling and bottom-water hydrothermal fluids led to environmental changes in the study area, from dry and hot to moist and warm. Last, the reconstruction of the tectonic environment of the Qiongzhusi Formation indicates that deposition occurred in continental slope and marginal marine environments associated with a continental arc tectonic system. These findings provide an essential basis for the comprehensive reconstruction of the early Cambrian sedimentary environment of the Yangtze Block.

Detailed geochemical and U-Pb studies of two diabases (Luoji and Cuiyi) from the Luoji area have been undertaken. The diabases are high-K calc-alkaline and belonging to the tholeiitic series, enriched in large ion lithophile elements, Ti, Zr and light rare earth elements, and depleted in high field strength elements. These characteristics are different from the oceanic island basalt but highly consistent with the continental rift basalt, indicating the Luoji and Cuiyi diabases are the products of the intracontinental rift related to the initial opening of the Ganzi-Litang Ocean. The Luoji and Cuiyi diabases originated from an enriched mantle source with a small degree of crustal contamination during their emplacement. Zircon U-Pb ages show that the Luoji and Cuiyi diabases were emplaced at 293.4 +/- 5.4Ma. Therefore, we propose that the time of initial rifting of the Ganzi-Litang Ocean occurred during the very Early Permian.

Lunpola Basin is the first exploration area with industrial oil flow in the hinterland of Tibetan Plateau and the target horizon is the Paleogene Niubao formation and Dingqinghu formation. Based on drilling data from multiple wells, the organic matter abundance, type and maturity of Paleogene source rocks in Lunpola Basin were measured and analyzed using organic geochemistry method. The 67 samples data from middle Niubao formation show that the average of TOC (wt.) is 3.50, S-1+S-2 is 30.55 mg/g; and the Tmax is 427 similar to 442 degrees C, delta(CPDB)-C-13 is -25.6 parts per thousand similar to -29.3 parts per thousand and Ro is 1.37%similar to 1.84%. The 53 samples data from upper Niubao formation show that the average of TOC (wt.) is 4.16%, S-1+S-2 is 30.16 mg/g. and the Tmax is 421 similar to 440 degrees C, delta(CPDB)-C-13 is -26.9 parts per thousand similar to -28.7 parts per thousand and Ro is 0.61%similar to 1.35%. The 70 samples data from lower Dingqinghu formation show that the average of TOC (wt.) is 4.16%, S-1+S-2 is 30.16 mg/g and Ro is 0.58%, and the Tmax is 421 similar to 440 degrees C, delta(CPDB)-C-13 is -26.9 parts per thousand similar to -28.7 parts per thousand. These three sets of source rocks have high organic abundance and kerogen type of I- II1. Based on the previous studies of W-1 well in JiangjiaCo depression, XL-3 well in JiangriaCo depression and Z-1 well PaCo depression, a 2D model of north-south tectonic and thermal evolution in Lunpola basin is simulated by Schlumberger's PetroMod method. The results show that the XL-5 well of Niubao formation in Diezong area of Lunpola basin began to generate oil at 41.3Ma and reached the peak of hydrocarbon generation at 36.4Ma; and upper Niubao formation began to generate oil at 38.4Ma and hydrocarbon generation peaked at 31.9Ma. The lower Dingqinghu formation began to generate oil at 24.2Ma. At the end of upper Dingqinghu formation, the basin began the uplift and denudation stage at 23Ma, but the middle and upper Niubao formation and the Lower Dingqinghu formation are still active for hydrocarbon generation. The simulation also shows that the primary deposits in main source rocks are thin in the thrust uplift belt of southern basin and have not entered the stage of oil generation, and that the main oil source area is the Paleogene depression in central basin.

The Jiajiwaxi pluton in the southern portion of the West Kunlun Range can be divided into two collision–related intrusive rock series, i.e., a gabbro–quartz diorite–granodiorite series that formed at 224±2.0 Ma and a monzonitic granite–syenogranite series that formed at 222±2.0 Ma. The systematic analysis of zircon U-Pb geochronology and bulk geochemistry is used to discuss the magmatic origin（material source and thermal source）, tectonic setting, genesis and geotectonic implications of these rocks. The results of this analysis indicate that the parent magma of the first series, representing a transition from I-type to S-type granites, formed from thermally triggered partial melting of deep crustal components in an early island–arc–type igneous complex, similar to an I-type granite, during the continental collision orogenic stage. The parent magma of the second series, corresponding to an S-type granite, formed from the partial melting of forearc accretionary wedge sediments in a subduction zone in the late Palaeozoic–Triassic. During continued collision, the second series magma was emplaced into the first series pluton along a central fault zone in the original island arc region, forming an immiscible puncture-type complex. The deep tectonothermal events associated with the continent–continent collision during the orogenic cycle are constrained by the compositions and origins of the two series. The new information provided by this paper will aid in future research into the dynamic mechanisms affecting magmatic evolution in the West Kunlun orogenic belt.