摘要
西秦岭金矿床分为卡林型和造山型两类。卡林型金矿床麇集于南秦岭和松潘—甘孜造山带的东北部。三叠纪和早侏罗世的同构造花岗闪长岩广泛分布于西秦岭中部和南部、松潘—甘孜盆地以及扬子克拉通边缘。造山型脉状金矿床主要分布于西秦岭造山带中的脆韧性剪切带内。大部分粗粒金主要赋存在网格状石英细脉和角砾状围岩中的黄铁矿、磁黄铁矿、毒砂和少量贱金属硫化物中和以分散状分布在蚀变围岩中。同位素资料表明晚三叠世 -中侏罗世与扬子克拉通俯冲有关的作用控制了造山型金矿床的形成。
Gold deposits of the western Qinling belt comprising Carlin type and orogenic type gold deposits. Carlin like gold deposits are abundant (1) along a westward extension of the southern zone defined by a window of early Paleozoic clastic rocks extending into the basin to the west and (2) within the easternmost margin of the basinal rocks, south of the extension, and in adjacent cover rocks of the Yangtze craton. Triassic and Early Jurassic synkinematic granitoids are widespread across the central and southern zones, as well as in the Songpan Ganzi basin and northern margin of the Yangtze craton.Orogenic lode gold deposits sited along brittle ductile shear zones occur throughout the central zone within greenschist facies, highly-deformed, Devonian and younger clastic rocks. Mainly coarse grained gold, along with pyrite, pyrrhotite, arsenopyrite, and minor base metal sulfides, occur in networks of quartz veinlets, brecciated wallrock, and disseminated in altered wallrock. Isotopic dates suggest that the deposits formed during the Late Triassic to Middle Jurassic as the leading edge of the Yangtze craton was thrust beneath rocks of the western Qinling belt. Both Carlin and orogenic types of gold deposits formed during extensional period of post orogenesis, aged mainly from 210-180 Ma.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2001年第1期11-13,共3页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家基础研究项目(G1999043211)部分研究成果。
关键词
西秦岭
造山带
卡林型金
western Qinling
orogenic type of gold deposit
Carlin type of gold deposit
