摘要
叶城晚新生代山前盆地沉积序列由中新统乌恰群 ,上新统阿图什组和上新统—更新统西域组构成。乌恰群岩性为细粒泥岩夹砂岩 ,阿图什组为砂岩夹薄层砾岩 ,西域组为粗粒砾岩。中新世的沉积以细颗粒泥岩和砂岩为主 ,表明物源区较远 ,古流域坡度较小 ,搬运距离较长。叶城剖面碎屑岩粒度总体上是沿剖面向上逐渐变粗 ,到上新统的阿图什组时 ,开始出现砾石沉积 ,砂岩的岩屑成分增加 ,成熟度降低 ,反映西昆仑山已经开始有规模地隆升。西域组的沉积标志着作为物源区的西昆仑山已有相当的高度。西域组砾石成分在剖面下部以沉积岩为主 ,向上过渡为沉积岩和深变质岩为主 ,反映了源区的沉积盖层首先被剥蚀 ,随着山系的隆升 ,基底岩石 (深变质岩和侵入岩 )也被暴露和剥蚀。
Late Cenozoic foreland basin deposits in Yecheng are composed of Moocene mudstone and sandstone(Wuqia Group),Early Pliocene sandstone with minor gritstone(Artux Formation) and Late Pliocene-Early Pleistocene conglomerate(Xiyu Formation). The Miocene strata are dominated by fine-grained clastic material,indicating a distal source and low gradient slope. Palaeocurrent measurements suggest a northward direction,indicating that the Kunlun area was at low elevation. Deposition of Artux Formation marked the first appearance of gravel and lithic detritus,indicating the uplift of Kunlun. Xiyu Formation is characterized by coarse debris flow deposits,marking the strong uplift of the northern part of Tibetan Plateau and unroofing of the West Kunlun.
出处
《地质力学学报》
CSCD
2002年第4期297-305,共9页
Journal of Geomechanics
基金
中国科学院"百人计划"
国家杰出青年基金项目 (编号 :40 0 2 5 10 7)
国家重点基础研究发展规划项目(编号 :G2 0 0 0 0 785 0 1)
教育部"长江特聘教授"计划资助项目
