柴达木震旦纪—三叠纪盆地演化研究  

TECTONIC EVOLUTION OF QAIDAM BASIN IN SINIAN—TRIASSIC

作　　者：汤良杰[1] 金之钧[1] 张明利 张兵山 由福报 骆静 

机构地区：[1]石油大学盆地与油藏研究中心,北京102200 [2]青海石油管理局研究院,敦煌736202

出　　处：《地质科学》1999年第3期289-300,共12页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国石油天然气集团公司"九五"重点科技攻关项目

摘　　要：柴达木盆地震旦纪—三叠纪构造演化经历了２ 个一级构造旋回，即震旦纪—中泥盆世开合旋回和晚泥盆世—三叠纪开合旋回，它们与祁连洋、赛什腾－ 锡铁山洋、昆仑洋和阿尔金洋在不同阶段伸展张裂、俯冲消减和闭合作用有关，其分划性时间界面分别为８００Ｍａ、３７７ Ｍａ 和２０８ Ｍａ，时间跨度分别为４２３ Ｍａ 和１６９ Ｍａ。第一个旋回自震旦纪开始张裂，柴达木形成大陆裂谷盆地；寒武纪—中奥陶世伸展为被动大陆边缘，柴达木表现为克拉通内（伸展）盆地；晚奥陶世开始俯冲消减，泥盆纪晚期碰撞闭合，柴达木形成克拉通内（挤压）盆地。第二个旋回表现为海西－ 印支期与南昆仑洋有关的弧后拉张－ 弧后造山事件，柴达木在晚泥盆世—早二叠世形成弧后裂陷盆地，晚二叠世—三叠纪形成弧后前陆盆地。在两个开合旋回的末期，均发生大规模盆地反转作用，导致柴达木及邻区构造格局、海陆分布和沉积特征发生根本变化。It is indicated that tectonic evolution of the Qaidam basin in Sinian—Triassic time underwent Sinian—Mid Devonian and Late Devonian—Triassic open-close cycles. The cyclicity of the basin evolution is mainly related to the extension, subduction and closure of Qilian, Saishiteng-Xitieshan, Kulun and Altun Oceans surrounding the paleo Qaidam. The time span of the former cycle is up to 423 Ma (800 —377 Ma). The latter revealled Late Devonian—Triassic back-arc extension and orogenesis, and lasted about 169 Ma (377 —208 Ma). The basin evolution of the Qaidam in Sinian—Triassic can be further devided into four second level tectonic stages, that is, (1) the formation of intra-cratonic extensional basin in Sinian—Mid Ordovician (800—464Ma), (2) the development of intra cratonic compressional basin in Late Ordovician—Mid Devonian (464—377Ma), (3) the evolution of back arc extension basin in Late Devonian—Early Permian (377—260Ma), and (4) the formation of back-arc foreland basin in Late Permian—Triassic (260—208Ma). The basin type experienced changes from extension to compression alternately in different stages.

关 键 词：盆地演化 构造旋回 盆地类型 柴达木盆地 震旦纪 

分 类 号：P542.3[天文地球—构造地质学] P544.4[天文地球—地质学]