东昆仑华力西—印支期花岗岩组合及构造环境  

ASSEMBLAGES AND TECTONIC ENVIRONMENT OF THE VARISCAN-INDOSINIAN GRANITOID IN THE EASTERN KUNLUN

作　　者：古凤宝[1] 吴向农[1] 姜常义[2] 

机构地区：[1]青海省区调综合地质大队 [2]西安地质学院

出　　处：《青海地质》1996年第1期18-36,共19页

摘　　要：本文采用花岗岩组合的研究方法,依据不同侵入体、不同单元相互间成因上的亲源性、空间共生性及构造环境的制约性,归属了十二个单元组合。将时空相互关联的单元组合归并为三种不同构造机制的花岗岩组合序列,并对其成因类型及系列作了论述。追踪研究了泥盆—石炭纪、二叠纪—中三叠世、中三叠世末—侏罗纪花岗岩源岩背景及成岩构造特点。The Eastern Kunlun granitoid belt,more than 800Km from west to east and 40-80Km in width, spans in the north of Qinghai-Tibet Plateau. The main body of the granitoidbelt is situated in the north of the central palaeosuture of the Eastern Kunlun. The granitoidwith multiperiodic activity and complex lithology is dominated by Variscan-Indosinian gran-ites. The geological characteristics of the Eastern Kunlun granitoid belt are listed in Table l. Taking advantage of the study method of granitoid assemblages (intrusive body-unit-assemblage-series) and based on the genetic consanguinity, spatial association and the re-striction of structural environment, 12 assemblages have been classified (see Table 2). Therelationship betweeen spatial distribution and structural environment of main granitoid as-semblages and its lithology,lithochemistry and geochemistry have been discussed. And thenin terms of the tectonic background of source rock, diagenetic tectonism and genetic fea-tures, the granitoid assemblages interrelated in time and space are combined into three tec-tonic series, that is, Devonian-Carboniferous continental-crust expending series, Permian-Middle Triassic B-type subducting series and Middle Triassic-Jurassic A-type oblique sub-ducting series. The tectonic background of the source rock of Devonian-Carboniferous continental-crustexpending series belongs to faulted system dominated by Late Proterozoic Paleosuture andthe northern Kunlun basement rock series (buried Archaeozoic). Its diagenetic tectonic sur-rounding is located in the northern wing of Anyemaqen expending rift zone. Accompanyingwith the evolution of the rift zone, the paleosuture was active-rift-warped-decollement ofbasement and cover, and the granitoid series changed from mantle-crust mixture type to crusttype. The granitoid is nonorogenic alkalic-calc-alkaline rock serier with bimodal type (highpotassium and low aluminihm),associated with gabbro, and lacks those rocks that containSiO_2,55%-45%. The tectonic background of the source rock of Permian

关 键 词：花岗岩组合 构造环境 东昆仑 花岗岩 

分 类 号：P588.121[天文地球—岩石学]