青海西金乌兰湖—玉树板块缝合带的基本特征

BASIC CHARACTERISTICS OF THE XIJIR ULAN LAKE-YUSHU PLATE SUTURE ZONE IN QINGHAI

摘要: 在青海南部西起西金乌兰湖、东至玉树巴塘一带,自北向南依次分布着上三叠统巴颜喀拉山群、柯南群、巴塘群及结扎群四套地层,它们之间均以断层为界。多年来一直被人们称为“同期异相”的产物。但对它们的形成发展及相互关系众说纷纭,莫衷一是,特别是产于巴壤群中的西金乌兰湖—玉树深大断裂（拉竹龙—西金乌兰湖—金沙江断裂的一部分）更是引人注目,被许多学者视为重要的板块缝合线。但对该断裂的玉树以西部分,因资料欠缺,述及甚少。近年来,随着青南地区1:20万区域地质调查的进展,在这一方面获得了大量的资料,并提出了一些新的看法。本文在搜集了该区历年资料的基础上,运用板块构造的理论,对该区的地质构造发展作一初步探讨。

Abstract: In this paper the Bayan Chawuma is considered as an indicator of the Xijir Ulan Lake-Yushu plate suture zone in Qinghai.The paper discusses the basic charac-teristics and genetic model of this plate suture zone and studies four differnt Late Triassic sequences in the area from the plate-tec- tonic point of view.Thes four sequence of strata are considered to be the products of different plate tectonic environments.