In the Sichuan Basin, the activity of the Huayingshan fault significantly affects the structural evolution of the sedimentary cover and promotes the formation of oil and gas fields, but further research is needed on its multi-stage segmented activity process. Based on aeromagnetic data, seismic profiles, well data, and previous research results, this study investigated the distribution characteristics, multi-stage activity process and segmentation characteristics of the Huayingshan fault as well as its influences on the structural evolution of sedimentary cover, and further explored the tectonic evolution of the Basin. This study found the following: (1) The Huayingshan fault is SW-NE-trending and extends into the sedimentary cover, causing fault-propagation folds in some seismic profiles. (2) The activity characteristics of different segments and different periods of the Huayingshan fault vary, and we divided it into three segments. (3) The Huayingshan fault controlled the local boundary of the uplift during the Cambrian-Middle Triassic, leading to different structural frameworks in central and eastern Sichuan during the Jurassic-present. (4) During the Cambrian, NW-SE extensional stress intensified, particularly in the basin's northeastern region; during the Late Silurian, the NW-SE extensional stress peaked in the Early Paleozoic; and during the Middle Triassic, the Sichuan Basin was located in the superposition area of the SE-NW-directed and NE-SW-directed compressive stresses.

Microbialites are important reservoirs for oil and gas. The mineralization of organic matter in microbialites during early diagenesis can produce acidic fluids that dissolve carbonate grains, and can also result in an alkaline pore water that precipitates cement. The mineralization of organic matter in microbialites and its effect on microbialite reservoirs have not yet been studied in detail. In this study, quantitative statistical analysis of the two-dimensional spatial occurrence of pores and microbial fabrics, in situ geochemical analysis of specific components (microbial, transitional zone, and fine spar fabrics), and qualitative evaluation of the implications for microbialite reservoirs were undertaken on microbialites from Member IV of the Leikoupo Formation, Sichuan Basin, China. The quantitative statistical analysis shows that pores are spatially associated with microbial fabrics, but porosity has a poor correlation with microbial fabric content. In situ geochemical data indicate that microbialites with different porosities experienced different processes of organic matter mineralization. The processes of organic matter mineralization such as oxidation and nitrate reduction can provide more dissolution micropores than the process related with sulfate reduction, whereas the process of organic matter mineralization related with Fe–Mn oxide reduction results in cementation. Micropores created by organic matter mineralization can act as fluid channels for later dissolution and are important in the development of microbialite reservoirs.

The Silurian strata in the Sichuan Basin hold significant exploration potential for shale gas, yet their interrelationships require further investigation. Utilising well data, seismic profiles and existing research, this study examines the structural characteristics of the Sichuan Basin during the Silurian, unconformity distribution characteristics between the Silurian and Permian strata and the extent of Silurian stratum denudation. It then analyses the structural evolution of the basin during the Silurian. The findings of this study include the following: (1) the Leshan–Longnvsi palaeo-uplift expanded from both northwest to southeast and southwest to northeast during the Silurian, whereas the eastern and southern Sichuan depressions migrated south-eastwards. (2) Three angular unconformity areas developed around the Leshan–Longnvsi palaeo-uplift, with the unconformity between the Silurian and Permian strata representing a disconformity. The extent of denudation of the Silurian strata increased from the core of the Leshan–Longnvsi palaeo-uplift to its periphery and decreased around the three angular unconformities. (3) The continuous Leshan–Longnvsi palaeo-uplift controlled the structural evolution of the Sichuan Basin in an extensional dynamic setting during the Silurian. The tensile stress from the passive continental margin at the western edge of the South China Block gradually propagated into the block, affecting Sichuan Basin deposits and Leshan–Longnvsi palaeo-uplift development.

The Sichuan Basin, located on the eastern margin of the Tibetan Plateau, is an intracontinental basin that developed in the Yangtze Block. The Cambrian–Silurian strata in this basin have enormous exploration potential in terms of natural gas, but their structural evolution during the Cambrian–Silurian remains controversial. Based on wells, seismic profiles, aeromagnetic data, and previous research results, this study investigated the structures related to the Leshan–Longnvsi palaeo‐uplift and the activity of the Cambrian–Silurian basement faults, revealing the activity of the extensional process during the Cambrian–Silurian. The results of this study were as follows: (1) the flattening of the bottom of the Permian strata in seismic profiles located in the Leshan–Longnvsi palaeo‐uplift revealed a large number of normal faults, grabens, and horsts in the Cambrian–Silurian strata, indicating that the Leshan–Longnvsi palaeo‐uplift was an extensional structure during the Cambrian–Silurian period; (2) balanced cross‐sections and strata isopach maps showed that all seven basement faults in the basin were normal faults during the Cambrian–Silurian; (3) Sichuan Basin was in an extensional setting during the Cambrian–Silurian; (4) seven basement faults controlled the extensional process during the Cambrian–Silurian in the Sichuan Basin.

Based on 2D and 3D seismic data, the latest drilling data and field outcrop data of the northern slope of the Central Sichuan paleo-uplift, the structural analysis method is used to analyze unconformity development characteristics and fault characteristics during the key structural transformation period, discussing the influence of the structural characteristics on the hydrocarbon accumulation of deep carbonate rocks. The results show that:（1） The two key unconformities of the Tongwan and Caledonian periods were primarily developed in deep carbonate rocks. Firstly, Tongwan’s unconformities are characterized by regional disconformities between the second and third members of the Dengying Formation, the top formation of the Sinian and the lower Cambrian, strips of which zigzag through the north and south sides of the study area. Secondly, the Caledonian unconformity is characterized by a regional unconformable contact between the lower Permian and the ower Paleozoic strata. From NE to SW, the age of the strata, which were subject to erosion, changes from new to old, the denudation distribution showing as a nose-shaped structure which inclines towards the ENE.（2） Boundary fault and transtensional strike-slip faults developed in the Sinian to Paleozoic strata. In profile, there are three types of structural styles: steep and erect, flower structures, ’Y’ and reversed ’Y’ type faults. In plane view, the Sinian developed extensional boundary faults extending in an almost NS direction, strike-slip faults developing and extending linearly in approximately EW, WNW and NE strikes in the Cambrian, with characteristically more in the south and less in the north.（3） The faults in the northern slope show obvious zonal deformations in transverse view as well as significant stages and stratified activity in a longitudinal direction. Among them, the activity of faults in the Sinian was the strongest, followed by the activity in the Cambrian period, the activity intensity of faults in the Permian period being the weakest. This fault activity can be divided into four periods: Sinian, Cambrian-Permian, the early Indosinian period and the late Indosinian-Himalayan period, the transtensional strikeslip faults being the products of oblique extensions of pre-existing weak zones in the Xingkai and Emei taphrogenesis, with a particular inheritance in the main faults.（4） Combined with hydrocarbon accumulation factors, it is considered that the epigenetic karstification of the Tongwan and Caledonian unconformities in the northern slope controlled the formation and distribution of carbonate karst reservoirs over a large area, also acting as a good pathway for oil and gas migration. The extensional faults developed at the margin of the NS trending rift, controlling the sag-platform sedimentary pattern in the Dengying Formation of the Sinian. Strike-slip faults in NE, WNW and ENE directions may control the microgeomorphological pattern inside the platform and intensify the differential distribution of grain beach facies. The multi-stage hereditary activity of strike-slip faults not only improved the porosity and permeability of the reservoirs, but also acted as the main channel of oil and gas migration, providing favorable conditions for the development of the current multi-layer gasbearing scenario in the northern slope of the Central Sichuan Basin.

The Hailar Basin, located in north‐east China, is a typical continental rifted basin that contains oil and gas. The basin formation process comprised several stages of construction and reformation with complex formation mechanisms. The Bayanhushu (BYHS) Sag is a secondary structural unit in the south‐west Hailar Basin with a significant resource potential, but its current poor exploration and insufficient understanding of the structural evolution characteristics are restricting further oil and gas exploration. Therefore, the study of the structural evolution of the BYHS Sag plays a pivotal role in the future exploration and development of oil and gas. There are different hypotheses on the formation mechanisms and structural evolution of the BYHS Sag. To further understand the evolutionary history of the BYHS Sag, a structural physical simulation experiment was used based on the structural interpretation and geometric analysis of a seismic section. Inversion validation was then undertaken by the 2DMove equilibrium profile recovery technology. It was found that the formation process of the BYHS Sag was mainly controlled by the western Adunchulu Fault. Faults on the section developed in succession from top to bottom. The fault plane experienced multiple changes, thus forming a special seat‐shaped structural pattern. Structural inversion occurred twice during the evolution of the sag. The compressive stress during the tectonic inversion mainly acted in a SE direction. It is inferred that this was related to the subduction of the Palaeo‐Pacific Plate under the Eurasian Plate and the intermittent compression caused by the transmission of stress of the arc–continent collision.

四川盆地加里东古隆起位于盆地中西部,龙门山构造带以东.分析古隆起形成演化及其动力学成因机理对研究盆地内构造变形和指导盆地深层油气勘探具有重要意义.本文基于前人研究成果,根据大量地震反射剖面和钻井资料,结合盆地周缘露头资料,开展新一轮的研究工作.通过对比分析不同区域地层特征,识别古隆起发育区的前二叠系缺失情况,以及各套地层尖灭点分布范围、不整合削截点和上超点.利用地震、连井剖面相结合方法,较为详细地刻画了加里东古隆的形态特征,进而认识古隆起的阶段性演化;以灯影组顶面古构造演化为研究对象,结合平衡剖面技术,确定了加里东古隆起的形成演化阶段,将其划分为震旦纪雏形期、寒武纪-志留纪发育期、泥盆纪-石炭纪剥蚀夷平期、二叠纪-中三叠世稳定埋藏期、晚三叠世-现今调整定型期5个阶段;结合区域构造背景和四川盆地基底断裂特征,进一步分析加里东古隆起动力学成因机理.综合研究认为,加里东古隆起的形成受控于区域构造活动和基底断裂分期分段活动的影响.是基底作"堑垒式"差异隆升使盆地出现"大隆大坳"此起彼伏的构造格局,从而影响了继承性古隆起的形成演化.

北京密云水库西水堡子-梨树沟韧性剪切带的形成与燕山期岩浆活动有关,研究该韧性剪切带的显微构造特征对确定其性质及成因机制具有重要的理论意义.通过野外剖面实测、岩石定向标本采集及镜下显微构造鉴定,表明断层拆离面以下为变质核杂岩,由长英质糜棱岩、糜棱岩化闪长岩、糜棱岩化黑云母片岩及糜棱岩化片麻岩组成.岩石的韧性组构非常发育,长英质矿物中常见蠕英结构、矩形边结构、机械双晶、核-幔结构等.片状矿物中常见S-C组构、云母鱼结构、显微膝折带等.水堡子-梨树沟韧性剪切带为NWW-SEE向剪切的伸展型韧性剪切带.

页岩的矿物学特征是页岩气储集层裂缝、渗流运移和后期压裂改造等相关研究的重要基础.应用X射线衍射分析,对川南威远地区W201井下寒武统筇竹寺组和下志留统龙马溪组两套海相页岩岩心样品进行了岩石矿物组成的定性和定量分析.结果表明,川南威远地区筇竹寺组和龙马溪组海相页岩主要由石英、黏土矿物和碳酸盐矿物组成,还含有少量黄铁矿等矿物,样品中石英含量分别为38.7％和31.8％,黏土矿物含量分别为26.1％和37.3％,形成于海相强还原沉积环境,有利于有机质的富集和保存,为页岩气的生成提供了良好的条件;筇竹寺组和龙马溪组脆性矿物含量均较高,平均含量分别为70.5％和58.7％,脆性指数分别为73.0％和61.1％,整体上具有良好的脆性和可压性,有利于后期压裂改造,是四川盆地页岩气勘探开发的重要目的层.