Distribution characteristic of rare earth elements of shale in northeastern Chongqing

XIAO Bin; LIU Shugen; RAN Bo; LI Zhiwu; YE Yuehao; LI Jinxi; JIANG Lei; WANG Han; TANG Wei

doi:10.13225/j.cnki.jccs.2016.1849

Abstract：In order to find out the characteristics,sources and its geological significance of REE in shale at the northeast of Chongqing Chengkou-Wuxi area of Upper Ordovician Wufeng formation (FM) and Lower Silurian Longmaxi formation (FM) using inductively couple-plasma mass spectrometry (ICP-MS),the rare earth elements and trace elements were tested on the northeast Chongqing Chengkou Mingzhong 1 1 shale samples.The 11 samples tested in this paper were combined with the previous samples of Wuxi Tianba area of 12 samples,the contents of the REE,geochemical parameters,geological significance,spatial distribution and distribution patterns were studied.Study shows that the rare earth elements in the northeast of Chongqing Chengkou-Wuxi areaare relatively depleted in shale,and the REE content in the Wufeng FM are slightly lower than in the Longmaxi FM.The correlation between ΣREE and large ion lithophile elements,like Sc,Ti,Cr,Zn,Zr,Nb,Th,Hf and Ta is very good,which indicates that the REE is mainly supplied by terrigenous minerals.The abrupt interface of the early sedimentary rate,REE and trace element ratio in the Wufeng FM shale may be the sedimentary response of Duyun movement (Caledonian movement second act) extends to the northeast of Chongqing Chengkou-Wuxi area.