赣东北元古代蛇绿岩Sm-Nd同位素年龄及地质意义  

Sm-Nd Isotopic Age of Proterozoic Ophiolites in Northeastern Jiangxi and Its Geological Significance

作　　者：邢凤鸣 徐祥[1] 陈江峰[2] 周泰禧[2] K.A.Foland 

机构地区：[1]安徽省地质科学研究所,合肥230001 [2]中国科学技术大学,合肥230026 [3]俄亥俄州州立大学

出　　处：《岩石矿物学杂志》1992年第2期120-124,共5页Acta Petrologica et Mineralogica

摘　　要：江南古陆东南缘赣东北弋阳—德兴—婺源一线有一条蛇绿岩带,普遍认为它是二个一级大地构造单元的分界线,形成于元古代。推断蛇绿混杂岩是元古代古洋壳俯冲时被挤上来的碎片;也有人认为它是中生代二大古陆之间的缝合线。Sm-Nd矿物等时线给出1034±16Ma(MSWD=1.0)的同位素年龄,它符合元古代缝合带的观点,而不利于中生代缝合带。There is an ophiolite zone along Yiyang-Dexing-Wuyuan in northeasternJiangxi at the southeastern margin of the Jiangnan oldland. It is widelyheld that the ophiolites is a boundary between two first-order tectonicunits, the Yangtze and South China blocks, consisting of fragments of ocea-nic crust squeezed up during its subduction in Proterozoic, but some consi-der that it is a Mesozoic suture between the two great old masses. Themineral Sm-Nd isochron gives an age of 1034±16 Ma (MSWD= 1.0 ), thussuggesting that the ophiolitic blocks may be a product of the Proterozoicsubduction of the oceanic crust rather than a Mesozoic suture.

关 键 词：蛇绿岩 同位素 年龄 钐-钕 地质 

分 类 号：P588.3[天文地球—岩石学]