塔里木盆地新生代海相沉积问题

CENOZOIC MARINE SEDIMENTATION PROBLEM OF THE TARIM BASIN

基于前人文献,对塔里木盆地新生代海相沉积问题进行梳理,进而探讨该盆地新生代海侵的次数和范围以及海退的时限、原因。研究表明,新生代,塔里木盆地至少经历古近纪的阿尔塔什晚期至齐姆根早期(古新世早期至古新世晚期)、卡拉塔尔期—乌拉根期(始新世中期)、巴什布拉克中期(始新世晚期至早渐新世)等三期海侵;塔里木盆地中新世仍有海相地层这一认识获得广泛认可仍需更多的地质证据来支持。塔里木盆地海侵范围在卡拉塔尔—乌拉根组沉积时期达到最大,向东可达玛扎塔格地区,在盆地北缘和南缘分别可以到达库尔勒以东地区和洛浦县阿其克以东地区。由于受到全球海平面变化和构造运动的共同影响,副特提斯海新生代从塔里木盆地退却的沉积记录包括齐姆根组顶部、乌拉根组顶部、巴什布拉克组第四段和第五段,时间上分别对应于古新世晚期、始新世中晚期和早渐新世。

Based on former studies, this paper combines the problems on Cenozoic marine sedimentation of Tarim basin and discusses the times and scope of transgression , and time and cause of the Paratethys regression from Tarim basin in Cenozoic. The results suggest that Tarim basin experienced at least three marine incursions in Cenozoic, they are Late Aertashi-Early Qimugen （the Early Paleocene to Late Paleocene） , Kalatar-Wulagen （ the Middle Eocene） and Middle Bashibulake （the Late Eocene to Early Oligocene）. Further evidence is needed for the recognition of the marine strata that existed in Tarim basin in Miocene. The maximum transgression corresponded to the Kalatar-Wulagen. Further, the seawater reached Mazhatagh, then the east of Kuala and the east of Aqike , which are northern and southern margins of Tarim basin , respectively. On the effect of global eustatic sea level change combined with tectonism in Cenozoic , the top of the Qimugen, the top of the Wulagen and, the fourth and fifth segments of the Bashibulake formed due to the Paratethys Sea regression , corresponding to Late Paleocene , Late Eocene and Early Oligocene, respectively.