青藏高原东北缘印支期宗务隆造山带  

Indosinian Zongwulong orogenic belt on the northeastern margin of the Qinghai-Tibet plateau.

作　　者：郭安林[1] 张国伟[1] 强娟[1] 孙延贵[1,2] 李广[1] 姚安平[1] 

机构地区：[1]西北大学大陆动力学国家重点实验室,西安710069 [2]青海省地质调查院,西宁810012

出　　处：《岩石学报》2009年第1期1-12,共12页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(40572138);西北大学大陆动力学国家重点实验室科技部专项经费资助成果.

摘　　要：位于柴达木地块北缘构造带(柴北缘构造带)与南祁连造山带间的宗务隆构造带发育晚古生代、早中三叠世地层以及石炭纪蛇绿岩地体和具有岛弧性质的二叠纪—早三叠世中酸性火山岩。三个侵入宗务隆带南侧的海西—印支期花岗岩(246Ma天峻南山花岗岩、238Ma青海湖南山花岗岩和215Ma二郎洞花岗岩)分别与俯冲和后碰撞相关。两期明显的构造变形为印支期造山构造和第三纪陆内构造活动印记,前者以300余公里长的韧性剪切带为代表,后者以大规模指向南的逆冲推覆作用为特征。宗务隆构造带经历了由陆内裂陷、洋盆发育和俯冲—碰撞造山的演化过程,既不同于其南侧的柴北缘构造带也不属于北侧的南祁连造山带,而是一在柴北缘和南祁连造山带共同构建的加里东陆块上发育起来的、具有完整板块旋回的印支期造山带。The Zongwulong tectonic belt situated in between the Northern Qaidum Tectonic Zone and the Southern Qilian Orogen is composed of late Paleozoic and early-middle Triassic strata as well as Carboniferous ophiolite and Permian-early Triassic are intermediate-acid volcanics. Three Hercynian-Indosinian granites: the Tianjunnanshan (248Ma), Qinghaihunanshan (238Ma) and Erlangdong (215Ma) granites outcropping in the southern Zongwulong belt are. related to subduction and post collision stages, respectively. Two distinct deformation phases represent the Indosinian orogenic structures and Tertiary intracontinental tectonic imprints. The former is characterized by a more than 300 km-long and it few kilometers, wide ductile shear zone and the latter by largescale and south-verging thrusting. Being different from the Northern Qaidum Tectonic Zone to the south and the Qilian Orogen to the north, the Zongwulong tectonic belt is likely an independent Indosinian orogenic belt, which was developed based on the early Paleozoic Caledonian orogenic basement and experienced a complete plate tectonic evolution from continental rifting, and oceanic basin to subduction-collision.

关 键 词：宗务隆构造带 天峻南山蛇绿岩 海西-印支期花岗岩 印支期变形 宗务隆造山带 

分 类 号：P588.146[天文地球—岩石学] P597.3[天文地球—地质学]