地质论评2013，Vol.59Issue(4)：637-655,19.
宁武—静乐盆地侏罗系碎屑岩地球化学特征及地质意义
Geochemistry of Jurassic Detrital Rocks and Geological Significance in Ningwu—Jingle Basin
摘要
Abstract
The Jurassic strata of the Ningwu--Jingle Basin,the Yongdingzhuang Formation of Lower Jurassic,the Datong,Yungang and Tianchihe Formation of Middle Jurassic,are primarily composed of siltstone and mudstone.Provenance area is mainly point to the central Yinshan--Yanshan Orogen according to former Jurassic Palaeogeomorphology and Paleocurrent.Based on the geochemical signatures of major elements,trace elements,and rare earth elements from 24 samples,which picked from Chenjiabangou profile on the Ningwu--Jingle Basin,three conclusions have been obtained.Firstly,in these samples,CO2 vs.CaO have a good correlation,δCe vs.δEu,δCe vs.Σ REE、CIA vs.Th/U、CIA vs.Th/Sc have no correlation,those imply that the Jurassic detrital rocks are mainly controlled by source characteristics,were not impacted by chemical weathering and oxidation —reduction conditions.Secondly,the distribution patterns of rare earth elements are basically the same,LREE/HREE ratios are high,Eu negative anomalies are evident,which show that provenance are the same during the Early--Middle Jurassic,and the rocks are the main pro-granite and felsic,and the parent rock debris come mainly from the upper crust,have no mantle material,those discrimination diagrams about REE--La/Yb,La/Th--Hf,Co/Th--La/Sc,Th--Hf--Co,SiO2/A12 O3-Σ REE,K2O/Na2 O--Σ REE prove the same viewpoint.Thirdly,during Yungang and Tianchihe of Middle Jurassic,a sudden rise on CaO content,CO2 content,Gd content,ICV,(Gd/Yb) n ratio,which show that the Provenance area is in rapid uplift and erosion stage,with a large number of ancient sedimentary material being added,the starting time of the Yanshan movement may be the early Yungang term of Middle Jurassic.关键词
宁武—静乐盆地/早—中侏罗世/碎屑岩/地球化学/物源属性Key words
Ningwu--Jingle Basin / Early--Middle Jurassic / detrital rocks / geochemistry / provenance引用本文复制引用
李振宏,董树文,渠洪杰,胡健民..宁武—静乐盆地侏罗系碎屑岩地球化学特征及地质意义[J].地质论评,2013,59(4):637-655,19.基金项目
本文为中国地质科学院地质力学研究所基本科研业务费项目(编号DZLXJK201208)、国家深部探测技术与实验研究专项(Sinoprobe-08-01)的成果. （编号DZLXJK201208）
