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The multi-stage tectonism of compression and extension occurred in the southern part of the Lower Yangtze region in the Mesozoic, which is one of the important factors restricting the breakthrough of oil and gas exploration in this area. This paper aims to reveal the influence of Mesozoic tectonisim on oil and gas preservation in the Lower Yangtze area. Based on the seismic profile interpretation data, field outcrop survey, regional tectonic evolution history analysis and the drilling core data and oil-gas display of the Well Wanjingdi-1, we comprehensively discussed the favorable structural preservation conditions in the southern part of the Lower Yangtze region. The results of seismic interpretation profile and surface survey show that the southern part of the lower Yangtze River has experienced two important tectonic processes since the Late Triassic. The first stage is fold deformation, thrust fault and uplift erosion caused by Indosinian compression, and the second stage is extension since the Late Cretaceous, resulting in the formation of fault basin and normal fault activity. Shale gas display was obtained from the Permian shale in the Well Wanjingdi-1, and light oil was found in the drilling of the Lower Triassic Yinkeng Formation, indicating that the southern Lower Yangtze region has good enrichment conditions and resource potential, which points out a new direction for oil and gas exploration in the region. The analysis of structural preservation conditions shows that the Well Wanjingdi-1 is located in the syncline of the fold-depression belt. The amount of uplift and denudation was small in the Indosinian period. Since the late Cretaceous, the depression has a small amplitude of extension and has good sealing and reservoir forming conditions. It is a favorable structural position for oil and gas preservation in this region. Based on the comprehensive analysis of regional structure and sedimentary basin evolution, it is considered that in the southern Lower Yangtze region, the syncline structural belt in the southern margin of the basin with small erosion amount of Triassic strata or the central zone of fault basin overlying thick Cretaceous-Cenozoic strata should be taken as the key target to search for favorable oil and gas zones.

[Objective] Marine red beds are distributed across various stages in geological history, are often interpreted as products of special environments, and have attracted widespread attention. The Sowa Formation in the Jurassic Qiangtang Basin is a set of sedimentary rocks composed of clastic and carbonate mixed sediments. In the Sowa Formation exposed in Bilocuo, Shuanghu county, Tibet, the red beds are mainly composed of carbonate sediments. [Methods] This study explored the causes of th red color and significance in the deposition and diagenesis of the red beds based on sedimentological, mineralogical, and geochemical methods. [Results] Field sedimentology and downhole thin section identification of these red beds revealed that the rocks are composed of grain-supported limestone, with abundant debris from cephalopods, echinoderms, bivalves, bryozoans, gastropods, and other benthic organisms. Biogenic debris and terrestrial quartz debris are the main components of the ooids, which display characteristics of a high-energy beach environment. Spectroscopic studies and scanning electron microscopy indicate that the main cause of the red color is submicron- to micron-sized pseudo-hexagonal and tetragonal hematite crystals. The coloration minerals are concentrated in the ooid cortex structure, and the cementing material is virtually devoid of coloration minerals. This suggests that during early diagenesis, particularly during the formation of ooids and peloids, iron-loving microorganisms played an important role in capturing iron oxides. Furthermore, the geochemical analysis of carbonate minerals shows that the redness is positively correlated with the flux of terrestrial debris input. Additionally, it exhibits a positive Ce/Ce* anomaly (1.1-1.3) and a pattern of enriched-middle rare earth elements "bulge", indicating that the iron oxides underwent reductive dissolution.[Conclusions] Based on these findings, the study reconstructed the red coloration process of these red beds. The input of terrestrial iron-bearing minerals provided the material basis for the red coloration, and then, during early diagenesis, reductive fluids dissolved the iron-bearing minerals, providing free iron ions for iron-loving microorganisms, allowing them to recrystallize and ultimately form hydroxyl iron and cause red coloration through chemical or biological processes. [ABSTRACT FROM AUTHOR]

The existing polyester stable fiber production can not separate the bag contain the end of fiber effectively, resulting in the uneven quality of the finished package, a set of automatic tracking isolation system who can effectively separate the package containing head and tail wire was designed. The system can record the generation time of head and tail wire accurately, re-positioning the lead wire according to this timestamp after the stretch operation, and achieving automatic isolation of the finished package containing the head and tail wire. The experimental results and the practical situation on the spot show that the number of packets is reduced by more than 50%, and the automatic isolation system of head and tail wire works efficiently and reliably. [ABSTRACT FROM AUTHOR]

The research on the marine PTB in Southern China has been well-established, and the significant breakthrough has been done on the terrestrial PTB in Eastern Yunnan Province, Western Guizhou Province and Tianshan Mountain, but not well enough on that of the Tibetan Tethys Region. This research conducted 13C-18Oisotopic composition analysis on the complete Permian-Triassic conodonts biostratigraphy column established by the previous study. The analysis results indicate an obvious negative excursion on the 13C isotopic composition at the PTB in the Wenbudangsang section, Tibet, but the excursion pattern is distinguished from that of the Meishan section, Southern China. To be specific, the pattern showed that its δ13Ccarb decreased as time passed by, which is similar to that of the PTB in Southern Alpes. Compared with the typical marine PTB in Yangtze Plateau which indicate the transition from carbonates platform to lower shelf facies, it suggests that the δ13Ccarb excursion pattern from the Wenbudangsang section (Tibet) is highly consistent with that of the Xishan shallow carbonates platform. The negative δ13Ccarb excursion at the PTB suggest there may be a significant land weathering resulting from land uplift during the Pangea convergence, with the tectonic-related volcanic activity co-occurring. [ABSTRACT FROM AUTHOR]