The uplift–depression framework controls the source–reservoir assemblage. However, the exploration breakthrough is restricted by an insufficient understanding of the uplift–depression differentiation framework in the Early Cambrian Keping–Wensu area. In this paper, based on field outcrops evaluations, thin section analysis, logging data, drilling data, and 3D seismic data, Wensu low paleo-uplift was discovered in the northern Tarim Basin, and the planar distribution was demonstrated in detail, generally shown as a SW–NE trending nose structure, extending roughly 114 km in length to the southwest, about 35 km in width to the northeast, and with the overall characteristic of being high in the west and low in the east. During the Early Cambrian, the Tabei paleo-uplift evolved into the Wensu low paleo-uplift and largely died out by the Middle Cambrian, with the development of ramps and rimmed carbonate platforms. The tectonic-sedimentary evolution of the uplift–depression framework controlled the development of a set of main source rocks and two sets of large-scale effective reservoir rocks in the Lower Cambrian, constituting two sets of effective hydrocarbon accumulation in the upper and lower stratigraphic parts of the basin. Among them, the upper assemblage holds more potential for hydrocarbon exploration, and is expected to be a next strategic target area for hydrocarbon exploration of Cambrian subsalt in the Keping–Wensu area.

The Mingshan reservoir of the Dabie Orogen has a number of Neoproterozoic bimodal intrusive rocks. We focused on the zircon U-Pb chronology, Hf isotopes, and bulk-rock geochemistry of these rocks. The results showed the following: (1) The bimodal intrusive rocks mainly consist of monzogranitic gneiss and plagioamphibolite, with zircon U-Pb ages of 785.0 ± 7.1 Ma and 787.3 ± 6.1 Ma, respectively. These ages indicate that they were formed in the late Qingbaikou epoch of the Neoproterozoic era. (2) The monzogranitic gneiss was dominated by peraluminous features and displayed a strong right deviation of REE (rare-earth element) patterns and a negative δEu anomaly. It is enriched in the LILEs (large-ion lithophile elements) Rb, Ba, and K, but slightly depleted in Nb, Sr, P, and Ti, with low 10,000* Ga/Al values, indicating that it is similar to Al-type granite. The plagioamphibolite belongs to the metaluminous, peraluminous series. It has a Mg^# (molar ratio of Mg to Mg + Fe) of 36.1~55.9 and is enriched in the LILEs Rb, Ba, and K, with a slight positive anomaly of Ba, and is depleted in Nb and Sr. (3) The monzogranite shows negative zircon εHf(t) values ranging from −13.4 to −7.2 and a Paleoproterozoic T_DM2(Hf) (two-stage depleted mantle model age) of 1969–2298 Ma. The zircon εHf(t) values and T_DM2(Hf) of the plagioamphibolite were concentrated around 2.9–5.7 and 1257–1410 Ma, respectively. The geochemistry and Hf isotopes show that the monzogranitic gneiss and plagioamphibolite have distinct magmatic sources. The plagioamphibolite formed from mantle and partial continental crustal materials. The monzogranitic gneiss, on the other hand, was formed as a result of the partial melting of the shallow ancient felsic crust caused by mafic rock heating or upwelling. Taking into account regional correlation, the middle Neoproterozoic bimodal intrusive rocks originated in the structural framework of an extensional setting.

The lacustrine to deltaic depositional systems of the Upper Jurassic Qigu Formation in the Yongjin area constitute a significant petroleum reservoir in the central Junggar Basin, China. Based on core observations, petrology analyses, paleoenvironment indicators and modern sedimentary analyses, sequence stratigraphy, lithofacies associations, sedimentary environment, evolution, and models were investigated. The Qigu Formation can be divided into a third-order sequence consisting of a lowstand systems tract (LST) and a transgressive systems tract (TST), which is further subdivided into six fourth-order sequences. Thirteen lithofacies and five lithofacies associations were identified, corresponding to shallow-water delta-front deposits. The paleoenvironment of the Qigu Formation is generally characterized by an arid freshwater environment, with a dysoxic to oxic environment. During the LST depositional period (SQ1–SQ3), the water depth was relatively shallow with abundant sediment supply, resulting in a widespread distribution of channel and mouth bar deposits. During the TST depositional period (SQ4–SQ6), the rapid rise in base level, combined with reduced sediment supply, resulted in swift delta retrogradation and widespread lacustrine sedimentation. Combined with modern sedimentary analysis, the shallow-water delta in the study area primarily comprises a composite system of single main channels and distributary channel-mouth bar complexes. The channel-bar complex eventually forms radially distributed bar assemblages with lateral incision and stacking. The distributary channel could incise a mouth bar deeply or shallowly, typically forming architectural patterns of going over or in the mouth bar. Reservoir test data suggest that the mouth bar sandstones are favorable targets for lithological reservoir exploration in shallow-water deltas.

The Ordovician platform margin belts in the Tarim Basin are key targets for deep carbonate hydrocarbon exploration. Their sequence architecture and spatial differences exert critical controls on the distribution of high-quality reservoirs. Taking the Early–Middle Ordovician platform margin belts in the Lunnan–Fuman–Gucheng area as the research object, this study systematically characterizes the sequence framework, sedimentary architecture, and segmented differential characteristics based on seismic, drilling, logging, and thin section data, using sequence stratigraphy, seismic facies analysis, and sedimentary mapping. The results show that five sequence boundaries are identified, dividing the Lower–Middle Ordovician into two second-order sequences and four third-order sequences. Seven types of mound-shoal seismic facies are developed, and three structural models are recognized from north to south: aggradation–weak retrogradation in the Lunnan section, weak aggradation–strong retrogradation in the Fuman section, and strong aggradation–weak retrogradation in the Gucheng section. It is revealed that differential subsidence caused by back-arc extension of the Altyn orogenic belt and the paleogeomorphic barrier effect of the Tadong Low Uplift collectively controlled the segmented architecture and migration evolution of the platform margin belts. The findings clarify the differential structural patterns of platform margins and provide a geological basis for hydrocarbon exploration in Ordovician platform margin reef-shoal complexes in the Tarim Basin.

In Mingshan reservoir of Dabie Orogenic Belt, there is a collection of Neoproterozoic bimodal intrusive rock formations. This study focuses on the zircon U-Pb chronology, rock geochemistry, and Hf isotopes of these formations. The findings reveal that: (1) The bimodal intrusive rocks mainly consist of gneissic monzogranite and biotite-bearing plagioclase amphibolite, with zircon U-Pb ages of 785.0 ± 7.1Ma and 787.3 ± 6.1Ma, respectively. These ages indicate that they were formed during the late Qingbaikou to early Nanhua epoch of the Neoproterozoic era. (2) The monzonitic granite in the peraluminous series displays a strong right deviation of LREE (Light Rare Earth Elements) and relatively flat HREE (Heavy Rare Earth Elements), as well as a negative δEu anomaly. It is enriched in elements like Rb, Ba, and K, while slightly depleted in elements like Nb, Sr, P, and Ti, similar to Al-type granite. The plagioclase-hornblende rock belongs to the metaluminous peraluminous, shoshonitic, and calc-alkaline series. It has a Mg# (molar ratio of Mg to Mg + Fe) of 0.15 ~ 0.25 and is enriched in LIL (Large Ion Lithophile) elements such as Rb, Ba, and K, with a slight positive anomaly of Ba, and depleted in Nb and Sr. (3) The monzogranite exhibits values of εHf(t) (epsilon Hafnium) ranging from − 13.4 to -7.2 (all negative), and tDM2(Hf) (two-stage depleted mantle model age) ranging from 2099 to 2298Ma. The amphibolite shows εHf(t) values ranging from 2.9 to 5.7 (all positive), and tDM2(Hf) ranging from 1257 to 1410Ma. The geochemistry and Hf isotopes indicate that the gneissic monzogranite and biotite-bearing plagioclase amphibolite have different magmatic sources. The mafic rocks originated from a depleted mantle and underwent fractional crystallization and strong crustal contamination. On the other hand, the acidic rocks resulted from partial melting of shallow ancient felsic crust due to the heating or upwelling of the mafic rocks. Taking into account regional correlation, the Middle Neoproterozoic bimodal intrusive rocks were formed in the structural setting of an intraplate extensional zone (incipient rift).