摘要
在青海西金乌兰湖地区移山湖和倒流沟一带发现的辉绿岩墙,侵入于泥盆系拉竹龙组变质石英砂岩、长石石英砂岩和元古宇宁多群灰白色白云母石英片岩、黑云母石英片岩中,岩石类型为辉绿岩、辉长辉绿岩,结合同位素测年及古生物证据分析其地质时代为晚泥盆世,可能与古特提斯北部河卡山东段克觉杂尔根基性岩墙群一样,反映了可可西里地区壳幔演变过程,是古陆块裂解、西金乌兰洋初始形成的证据。
The diabase dike swarms found in the Yishan Lake-Daoliugou zone, Xijir Ulan Lake area, Qinghai are emplaced in the metamorphic quartz sandstone and feldspar quartz sandstone in the Devonian Lazhuglung Formation, and grayish white muscovite quartz schist and biotite quartz schist in the Proterozoic Ningduo Group. The rock types include diabase and gabbro-diabase, which exhibit the crystallization differentiation of the magmas, and may be traced back to the Late Devonian. These diabase dike swarms, just like the basic dike swarms in (Kejuezargen), eastern Heka Mountains, Qinghai, may record the crust-mantle evolution in the Hoh Xil region, and attest to the breakup of the palaeocontinent and initiation of the Xijir Ulan Ocean.
出处
《沉积与特提斯地质》
CAS
CSCD
2004年第3期38-42,共5页
Sedimentary Geology and Tethyan Geology
基金
中国地质调查局"1:25万可可西里湖幅(I46C001001)地调项目成果"(2000130009211)。
关键词
西金乌兰湖地区
西金乌兰洋
晚泥盆世
辉绿岩墙
初始裂解
青海
Xijir Ulan Lake area
Xijir Ulan Ocean
Late Devonian
diabase dike swarms
initial breakup
Qinghai