Structural Characteristics Of The Xidamingshan Uplift In Guangxi And Its Relationship With The Adjacent Basins

Based on abundant first-hand field materials, combined with the regional geology, petroleum-natural gas exploration and the other material and achivement, directed by the idea of active and stages, and applied advanced methods, such as structural analysis and balanced section, the regional structure, deep faults, structural styles,structural deformation sections, the characteristics of tectonic stress field and the relationship with the adjacent basins were analysed in it. And obtained these results, they are: (1)Xidamingshan uplift developed two series sediments: the marine facies sediments from Paleozoic era to middle Triassic period and the continental facies sediments from late Triassic period to early Tertiary era, the total thickness is about 10,000 meters. (2)The dominating effect controlled Xidamingshan uplift's structural framework were the faults zone towards northeast (Xialei-Lingma fault zone,Fusui fault zone,Pingxiang-Dongmen fault zone) and northwest (Nandan-Du'an fault zone,Youjiang fault zone),all these were great deep faults that has long-time activity. The northeast controlled it's development and evolution,the northwest influenced the distributed of the defortion sections. (3)Structural styles in research area include four kinds: compression structure,extension structure,resersal structure and strike-slip structure. The major styles is the compression structure. It is indicated that the direction of compression thrust and shortening displacement are south or southeastto north or northwest. (4)Ploted eight structure deformation sections in Xidamingshan uflift,they are: Tiandeng fault-fold belt,Wuming fault-fold belt,Longzhou fault-fold belt,Suxu fault-fold belt,Chongzuo slitly fold belt,Kunlunguan salient,Daxin salient and Nan'ning basin. Each section has different structural characteristics. It's north boundary is the Xialei-Lingma fault zone, the south is the Pingxiang-Dongmen fault zone. (5)The paleostress field characteristics in reserch behaved that,mainly near south to north compression folding-uplift movement in Caledonian orogeny, and also in Indosinian orogeny, west-north to east-south in Hercynian orogeny and in early Yanshan orogeny, north-eastnorth to south-westsouth in late Yanshan orogeny, east to west in early Himalayan orogeny and south to north in late Himalayan orogeny. (6)The tectonic evolution of the Xidamingshan uplift can be mainly divided into three stages: Sinian period to Silurian period is the foundation evolution stage, Devonian period to mid-Triassic period is the regional extension-depression stage and late Triassic period to Cenozoic era is the compressional structural deformation and uplift-erosion stage. In it's evolution,Xidamingshan uplift devided-blocked the Shiwanshan basin and the Nanpanjiang depression. In every stage,it has different relationship between the adjacent basin and the evolution of the petroleum-natural gas.