地质通报2016，Vol.35Issue(6)：979-988,10.
黔北大方地区二叠系-三叠系界线粘土及事件粘土地球化学特征及成因
Geochemical characteristics and genesis of T/P boundary clay and event clay in Da-fang aera, Guizhou Province
摘要
Abstract
The Permian and Triassic strata are widely distributed over Dafang area, Guizhou Province. Clay at the boundary between Permian and Triassic was discovered which is 12~14cm in thickness. There are 3~4 beds of volcanic event clay above the boundary clay which are 5~18cm in thickness. K2O ang MgO are relatively high in boundary clay between Permian and Triassic, event clay and volcanic event clay lie at the bottom of Songzikan Member. Their REE characteristics are also similar to each other. Boundary clay and event clay are both related to volcanic activity, as shown by Eu deficiency. Eu deficiency of boundary clay is more obvious than that of event clay, and some of this clay also show Ce deficiency. Tectonic background of boundary clay and event clay is related to felsic volcanic ash deposit in active continental margin, which is different from things of mud of Shabaowan Member and Jiujitan Member whose source area was feldspar arenite. Most of the trace elements in boundary clay are similar to those in event clay except Th, Y, Nb, Cd, Ga, In and Ta which are much higher than in volcanic event clay. It is thus inferred that there might have existed a little material from cosmic event in boundary clay.关键词
贵州省/大方地区/二叠系-三叠系界线/界线粘土/事件粘土/地球化学特征Key words
Guizhou Province/Dafang area/boundary between Permian and Triassic/boundary clay/event clay/geochemical charac-teristics分类
天文与地球科学引用本文复制引用
谭梅,赵兵,周冰洋,张晓诗..黔北大方地区二叠系-三叠系界线粘土及事件粘土地球化学特征及成因[J].地质通报,2016,35(6):979-988,10.基金项目
中国地质调查局项目 （）
