你好,请
登录
首页
平台概况
新闻中心
中心新闻
行业新闻
媒体关注
平台资源
资源列表
平台服务
机时安排 A
机时安排 B
投诉建议
服务成效
服务成效
服务案例
下载中心
中心发布
调试工具
运行环境
关于
联系我们
发展历程
BJSHRIMP
平台组建背景
搜索
返回
Forming age and tectono-petrogenises of the Jiugequan ophiolite in the North Qilian Mountain- NW China
[
查看
]
XIAXiaoHong
、
SONGShuGuang
The Jiugequan ophiolite is one of the representative ophiolite fragments in the Early Paleozoic orogenic belt of the North Qilian Mountain. It has been drawn much attention and extensively studied in recent years. In this study, ion microprobe (SHRIMP) U-Pb dating was carried out for zircons from isotropic gabbro from the Jiugequan ophiolite. Eighteen analyses yield a relatively consistent apparent 206Pb/238U ages from 480 to 508 Ma with a weighted mean age of 490±5 Ma (MSWD=1.06), which is believed to be the crystallization age of the gabbro and thus the forming age of the Jiugequan ophiolite. Major and trace element geochemical study indicates that the diabase-basalts from the Jiugequan ophiolite have N-MORB and E-MORB characteristics with some subduction-related signatures. The petrological, geochemical and chronological data enable us to conclude that the Jiugequan ophiolite is most likely to be formed at a spreading center of back-arc basin during the early Ordovician, while the ancient Qilian oceanic plate subducted northwards. The acquisition of forming age and determination of tectonic setting for Jiugequan ophiolite provide significant constraints on the evolution of intra-oceanic subduction system in the North Qilian orogenic belt during the Early Paleozoic era.
© BJSHRIMP 2013 - bjshrimp.cn