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The Early Mesozoic tectonic regime of the South China Block was characterized by strike‐slip movement. The northeastern South China Block dominated by recumbent folding, thrusting, and foreland imbrication. Between the North and South China blocks in southern Qinling, there was dextral transpression, but in the western South China Block, sinistral transpression took place. In central South China, sinistral transtension prevails. In contrast, both the eastern and western South China margins, composed of Precambrian basement, appears to be little deformed. These differences are due to lateral extrusion of the South China Block. Extrusion resulted from (a) an overall southerly compression (the North China Block against the South China Block) and indentation of the rigid North China Block into the weaker South China Block, (b) unconstrained South China southern margin, containing a subduction zone between the Indochina Block and the South China Block, allowing the escaped materials to be consumed, (c) an association of strongly constrained margins of the central Sichuan Craton in the western South China margin and the Southeast China Massif in the eastern South China margin, (d) structural obstacle of the Jiangnan Uplift mainly composed of the Proterozoic metamorphic basement, and (e) a previously thickened, gravitationally unstable, thermally weakened crust of the eastern Yangtze valley. The extrusion deformation began about at the beginning of the Jurassic/the end of the Triassic, and terminated at the end of the Cretaceous. [ABSTRACT FROM AUTHOR]

For the gas reservoir of the fourth Member of Dengying Formation in Moxi area, Sichuan Basin, the reservoir space is various, the reservoir heterogeneity is strong and the fluid seepage law is complex. The development process of gas reservoir shows the following characteristics. (1)The gas well has a large difference in productivity, mainly in medium and high production wells. (2)There are great differences in stable production capacity of gas wells, and most of them have strong stable production capacity. (3)Staged acid fracturing technology and special technology wells can greatly improve gas well productivity. In order to find out the distribution characteristics of gas well productivity, gas reservoir engineering research and comprehensive geological research are combined to analyze the distribution characteristics of gas well productivity in the plane. The research shows that the gas well productivity characteristics have obvious subdivision of areas and belts characteristics in the plane. The gas well productivity is mainly distributed in four areas in the plane. The first area is that the thickness of overlying limestone is 0 m. The second area is that the thickness is 0-5 m. The third area is that the thickness is 5-20 m. The fourth area is that the thickness is more than 20 m. At the same time, the fitting formula of gas well productivity and overlying limestone thickness in different regions has been established. On the other hand, gas well productivity is mainly distributed in three belts which include platform edge, platform interior and slop belt. The gas well productivity decreases from platform edge, platform interior to slop belt. The research results can effectively support development area selection, well location optimization in the process of gas reservoir development evaluation and gas well productivity evaluation. [ABSTRACT FROM AUTHOR]

On 12 May 2008, the devastating magnitude 7.9 (Wenchuan) earthquake struck the eastern edge of the Tibetan plateau, collapsing buildings and killing thousands in major cities aligned along the western Sichuan basin in China. After such a large-magnitude earthquake, rearrangement of stresses in the crust commonly leads to subsequent damaging earthquakes. The mainshock of the 12 May earthquake ruptured with as much as 9 m of slip along the boundary between the Longmen Shan and Sichuan basin, and demonstrated the complex strike–slip and thrust motion that characterizes the region. The Sichuan basin and surroundings are also crossed by other active strike–slip and thrust faults. Here we present calculations of the coseismic stress changes that resulted from the 12 May event using models of those faults, and show that many indicate significant stress increases. Rapid mapping of such stress changes can help to locate fault sections with relatively higher odds of producing large aftershocks. [ABSTRACT FROM AUTHOR]