四川及邻区晚二叠统吴家坪碳酸盐缓坡沉积

CARBONATE RAMP SEDIMENTATION OF PERMIAN IN WUJIAPIN,SICHUAN AND ITS NEIGHBOURING REGION

四川及邻区上二叠纯吴家坪组石灰岩属于碳酸盐缓坡沉积,与北、东及东北方向的同期盆地相沉积渐变过渡;在西南近滨地区发育浅水高能带,与同期龙潭组陆源沉积过渡,形成特殊的陆源碎屑——碳酸盐混合沉积。由于持续的海侵及碳酸盐的快速沉积作用,碳酸盐缓坡逐渐向台地转化。最终形成该区晚二叠晚期的碳酸盐台地。吴家坪碳酸盐缓坡的古地理控制着该区上二叠统不同类型生物礁油气藏的分布。

The Limestone(Upper Permian) in wujiapin was deposited on a carbonate ramp in Sichuan and its neighbouring region, and gradually transitted with the basin facies northwards, eastwards and northeastwards. The shallow water high energy zone of the ramp was developed in southwestern off-shore area, characteristed by the mixed deposition of terrigenous clastic-carbonate. In the Late Permian, the carbonate ramp gradually transformed into the carbonate platform. It was the paleogeography of the carbonate distribution of the reef-gas-pool in Upper Permiam in this ares.