摘要
在西金乌兰发现一套晚二叠一早三叠世的石英砂岩和底砾岩,不整合于晚古生代。蛇绿混杂岩之上。沉积构造、结构、成分和粒度分析结果证明这套石英砂岩为海滩亚相石英砂岩;其物源区大地构造背景为克拉通内陆块,沉积环境为稳定陆块边缘,类似被动大陆边缘。表明本区古特提斯洋于早二叠世末一晚二叠世初基本闭合后,在晚二叠一早三叠世处于相对稳定阶段。
A set of Late Permian-Early Triassic quartzose sandstone was found in the Xijin Ulan area, Qinghai Province during the Hoh Xil comprehensive scientific expedition in 1990. Together with the basal conglomerate, it overlies unconformably the Early Carboniferous-Early Permian ophiolitic melange. The quartzose sandstone, has been proven to be beach-subfaacies sandstone. The tectonic setting of the provenance of the quartzose sandstone is craton interior landmass. The depositional environment of the sandstone is craton margin. It indicates that paleotethyan ocean fundamentally closed at the end of Early Permian-the beginning of Late Permian. During Late Permian-Early Triassic Xijin Ulan and its adjacent areas were relatively stable.
出处
《地质科学》
CAS
CSCD
北大核心
1993年第4期327-335,共9页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
中国青海可可西里综合科学考察成果之一
关键词
石英砂岩
海滩亚相
大地构造
Xijin Ulan, Quartzose sandstone, Beach-subfacies, Passive continental margin, paleotethys