Geochemistry and Geochronology of Shangyupo Biotite Schist in the Zhongtiaoshan Mountains: Implications for Its Petrogenesis
详细信息
- 责任者：Zhang Han (College of Earth Science ; Jilin University ; Changchun 130061 ; China) ; Sun Fengyue
- 刊名：Earth Science
- 出版年：2013
- 卷期：38(1)
- 页码：p.10-24
- issnNo：ISSN1000-2383
- isbnNo：CN42-1233/P
摘要
The primary compositions of the anticline core at Shangyupo are Beiyu meta-granitoid,meta-rhyolite and meta-mafic rocks.The age and petrogenesis of the biotite schist have been under debate for a very long time.The petrology features and geochemistry of Shangyupo amphibole/scapolite biotite schist are cricoid gradually distributed from the anticlinal core to its edge.The K,Ca,Na,Rr,Sr and Ba have been changed systematically by the high salinity fluid from the ductile shear belts,and Ta and LREE are also shown to have been dramatically changed in this event.LA-MC-ICPMS zircon U-Pb dating for the Shangyupo meta-rhyolite and the meta-ryholite of Jiangxian group yield the weighted mean 207Pb/206Pb age of 2 160.5±7.8Ma and 2 161.3±1.5Ma respectively.The Shangyupo meta-ryhorite and biotite schist may have been formed during the Jiangxian volcano event between 2.20～2.15Ga,based on the chronology and comparison to related rocks.The HFSE pairs show that the biotite schist is a subalkaline mafic rocks instead of the alkaline mafic rocks as previously suggested.The Jiangxian event may represent a tensional event related to the subduction,based on the comprehensive geological information of Zhongtiaoshan area.