摘要
通过对洪古勒楞东段蛇绿岩的研究，基本搞清了蛇绿者组合特征及其形成时代，首次指出该区在晚震旦世为广阔大洋环境，为研究准噶尔的大地构造演化提供了证据。依据蛇绿岩与围岩的接触关系，指出了其构造侵位时间为奥陶纪末，而与泥盆系则为断层接触。通过Ｓｍ－Ｎｄ等时线法测年结果确定蛇绿岩形成于６２６±２５Ｍａ。从稀土元素、岩石化学和εＮｄ（Ｔ）＝十８．４等综合分析，蛇绿岩来自亏损地幔岩浆，纯属洋中脊产物。
The ophiolites assemblage is basically clarified. The age of the ophiolites is inferred to be lateSinian.It is pointed for the first take that the study area was lotated at a wide oceanic environment at the lateSinian. A substamiat baste is so built for the study of geotectonic evolution in Junggar. The ophiolites wereintruded at the end of Ordovician according to its contact with the country rocks, and its fault comed withthe Devonian. The Sm-Nd isochron dating reveals that the ophiolites were formed at 625±25 Ma. The rareearth element, petrologital chemistry and εNd (r)=+8. 4 reveal that the ophiolites were derived from deficitmantle magma, totally of oceanic mid-ridge product.
出处
《新疆地质》
CAS
CSCD
1995年第1期20-30,共11页
Xinjiang Geology
