摘要
白济汛镁铁-超镁铁岩由吉岔蛇纹岩和俄咱辉长岩岩块组成,属澜沧江缝合带中的蛇绿岩块体。锆石 SHRIMPU-Pb 年龄测定表明,吉岔蛇纹岩(>297Ma)和俄咱辉长岩(303Ma)与金沙江缝合带中蛇绿岩的形成时间(300~294Ma)一致。说明金沙江缝合带和澜沧江缝带中的蛇绿岩,同为三江地区古特提斯洋盆扩张期形成的洋壳残片。
The Baijixun mafic-ultramafic rocks are belong to Lancangjiang ophiolite belt, and are composed of rock mass and tectonic rock slice, and can be divided into the Jicha serpentine and the Eza grabbro. Dated using the ziron SHRIMP U-Pb, the magmatic age of the Jicha serpentine is over 297Ma and the Eza grabbro is 303Ma, and the Jinshajiang ophiolite (300 -294Ma)is formed in same the time. This indicates the Baijixun mafic-uhramafic rocks and Jinshajiang ophiolite were from ocean crust relic, which were formed in same period of Sanjiang Paleo-Tethyan oceanic basin extension.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第6期1297-1301,共5页
Acta Petrologica Sinica
基金
国家自然科学基金项目(40572052)的部分成果