塔里木盆地奥陶纪层序岩相古地理

Sequence Lithofacies Paleogeography of Ordovician in Tarim Basin

通过大量钻井取芯及露头沉积相观察、地震层序解释及地震相分析,结合蛇绿混杂岩带及板块构造演化等区域地质资料,首次编制了层序地层格架下的8张塔里木盆地奥陶纪岩相古地理图,发现了塔里木板块内部存在5个孤立碳酸盐台地(塔北台地、巴楚—塔中台地、罗西台地、塘南台地及库鲁克塔格台地)及其"台—盆"相间的古地理格局,对塔里木盆地海相油气勘探具有重要指导意义。最初发生于早震旦世及早寒武世的塔里木板块北缘大陆裂谷运动及震旦纪—中奥陶世的张裂构造环境控制了塔里木板块内部多个孤立碳酸盐台地及其间深水沉积区的形成,而晚奥陶世发生于板块南缘的阿尔金岛弧及库地岛弧与塔里木板块的碰撞挤压运动及其产生的大量陆源碎屑物源,则导致了板块内部多个孤立碳酸盐台地的逐步消亡及板块南部浊流盆地群的形成。

Based on sedimentary facies observation of many wells cores and outcrops, seismic sequence interpretation and seismic facies analysis, synthesizing the regional geological data such as ophiolite-melange and plate tectonic evo lution, it＇s first worked out the 8 lithofacies paleogeography maps of Ordovician in Tarim basin under the sequence stratigraphy framework （Fig. 1, Fig. 2, Fig. 9 to Fig. 12, Fig. 16 and Fig. 17 ） , and found the 5 isolated carbonate platforms （Northern Tarim Platform, BaChu-Central Tarim Platform, Western LuoBuBo Platform, Southern Tarim Platform, KuLuKeTaGe Platform） of Ordovician in Tarim plate and the basins between them, it＇s very important to marine oil ＆ gas exploration in Tarim basin. The continental riftogenesis initially developed at the northern margin of Tarim plate in Cryogenian and Early Cambrian, and the tensional stress tectonic environment from Late Neo-proterozoic to Middle Ordovician, controlled the formation of several isolated carbonate platforms and the deep water sedimentation areas between them in Tarim plate, otherwise, the collision compressional movement developed between AErJin arc, KuDi are and Tarim plate at the south margin of Tarim in Late Ordovician and abundance terrigenous clasts produced by the collision, brought on gradually disappear of isolated carbonate platforms and the formation of turbidite sedimentary basins distributed in the southern Tarim.