塔西南昆仑山前地区晚白垩世沉积演化

Evolution of sedimentary environment in late Cretaceous,Kunlun Mountain Front,Tarim Basin

为阐明塔里木盆地昆仑山前地区晚白垩世沉积演化,以野外实测剖面为基础,结合样品分析测试,综合井下资料分析,结果表明:昆仑山前地区上白垩统自下而上可分为库克拜组、乌依塔克组、依格孜牙组及吐依洛克组,其中,库克拜组可分为"下红上绿"两段,下红段为棕红色砂泥岩、上绿段为灰绿色泥岩夹灰岩,乌依塔克组和吐依洛克组岩性类似,均为红色的含膏砂泥岩,依格孜牙组以"红灰岩"为特征。各组地层自西向东均有减薄趋势。上白垩统沉积时期发生2次大规模的海侵-海退,每个组段发育有典型而又相对单一的沉积相类型,自下而上发育辫状河三角洲(库克拜组)-潮上蒸发砂泥坪(乌依塔克组)-碳酸盐岩台地(依格孜牙组)-潮上蒸发砂泥坪(吐依洛克组)。

In order to reveal the sedimentary facies in late Cretaceous of Kunlun Mountain front, Tarim Basin, according to the outcrops, log information and the analysis of sample testing, the results show that the upper Cretaceous of Kunlun Mountain front can be divided into four formations from bottom to top： Kukebai, Wuyitake, Yigeziya and Tuyiluoke formation. Brownish red sand and silt rocks in the lower and greyish-green mudstone clip limestone of upper Kukebai formation. Wuyitake and Tuyiluoke formations have similar lithology, anointed with mudstone. Red limestone is the main rocks of Yigeziya formation. Strata of upper Cretaceous get thinner from east to west. Two large scale transgression-regression cycles can be distinguished in upper Cretaceous, and each formation or section developed typical and relatively single sedimentary facies. From bottom to top developed braided delta, evaporative sand-mud supratidal zone, carbonate platform and evaporative sand-mud supratidal zone.