四川石棉地区前震旦纪“康定杂岩”的时代探讨  

DISCUSSION ON AGE OF THE PRESINIAN “KANGDING COMPLEX” IN SHIMIAN,SICHUAN

作　　者：喻安光[1] 陈玉禄[1] 

机构地区：[1]四川地勘局区调队

出　　处：《四川地质学报》1999年第3期200-203,共4页Acta Geologica Sichuan

摘　　要：四川石棉地区的前震旦纪基底变质杂岩（“康定杂岩”） 呈断块产出，由中浅（深） 变质岩、变质侵入岩及混合岩组成。在片岩中获蓟县纪—青白口纪球藻类化石；采用锆石ＵＰｂ 法和ＰｂＰｂ 法获得变粒岩的原岩年龄为１０６７Ｍａ，变质砂岩的成岩年龄小于８５３Ｍａ，变质侵入岩的成岩年龄为８７６ ～８２８Ｍａ，混合岩的变成年龄为７１１Ｍａ，结合早震旦世岩体侵蚀混合岩，故将基底变质杂岩的时代确定为蓟县纪—青白口纪。Kangding complex” as the Presinian basement metamorphic complex in Shimian,Sichuan occurs in blocks,and consists of low to moderate grade metamorphic rock,metamorphic intrusive rock and migmatite Schist yields algal fossils in the Jixian Qingbaikou age Gralulitite gives a U Pb and Pb Pb age for zircon of 1,067 Ma,metasandstone yields isotopic ages less than 853 Ma,metamorphic intrusive rock gives an isotopic age of 876～828 Ma and migmatite yields an isotopic age of 711 Ma In combination with the Early Sinian intrusion in the migmatite,the Kangding complex should be Jixian Changcheng in age

关 键 词：石棉地区 变质杂岩 同位素年龄 时代探讨 

分 类 号：P534[天文地球—古生物学与地层学]