白云鄂博矿床形成于不同时代的信息——矿床西矿体的年龄和讨论  

Information about ore deposit formation in different epochs:Age of the west orebodies of the Bayan Obo deposit with a discussion

作　　者：张宗清[1] 唐索寒[1] 王进辉[1] 袁忠信[2] 白鸽[2] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质科学院矿产资源研究所,北京100037

出　　处：《中国地质》2003年第2期130-137,共8页Geology in China

基　　金：国土资源部地质大调查项目(DK2001020-2)

摘　　要：白云鄂博铁-铌-稀土矿床的成矿时代长期争论。笔者报道了采自矿床西矿体铌-稀土-铁矿石样品和白云岩样品的Sm-Nd等时年龄和Rb-Sr等时年龄。Sm-Nd等时年龄为809±80(2σ)Ma,INd=0.511182±34(2σ),MSWD1.10;Rb-Sr等时年龄近似于391±97(2σ)Ma,ISr=0.70453±72(2σ),MSWD47。西矿Sm-Nd等时年龄与矿床主、东矿相同年代学方法年龄不同。白云鄂博矿床可能形成于中、新元古代,并在早古生代加里东期遭受过后期地质作用改造。西矿同主、东矿一样,在加里东期,铁矿石和白云岩的Sr同位素系统发生过扰动或再置。There has been a long dispute about the age of the Bayan Obo iron-niobium-REE deposit.This pa-per reports the Sm-Nd isochron age and Rb-Sr isochron age of iron-niobium-RE E ore samples from the west orebodies of the deposit.The Sm-Nd isochron age is80 9 ± 80(2 -Sr isochron is approximately391 The Bayan Obo deposit may have formed in the Meso-and Ne oproterozoic and undergone subsequent modification of geological processes in th e Early Paleozoic Caledonian.As is the case with the principal and east orebodie s,the Sr isotope system of iron ore and dolomite of the east orebodies was distu rbed or reset in the Caledonian.

关 键 词：白云鄂博矿床 铁-铌-稀土矿床 成矿时代 白云岩 Sm-Nd等时年龄 Rb-Sr等时年龄 地质作用 铁矿石 

分 类 号：P597.3[天文地球—地球化学]