Genesis of Kaolinite Deposits in the Jungar Coalfield,North China:Petrological,Mineralogical and Geochemical Evidence

作     者：LIU Linsong ZHANG Tongjun LIU Jianping LIU Qinfu LI Kuo LIU Di LIU Wanyue LIU Linsong;ZHANG Tongjun;LIU Jianping;LIU Qinfu;LI Kuo;LIU Di;LIU Wanyue

作者机构：College of Geoscience and Surveying EngineeringChina University of Mining and TechnologyBeijing 100083China Shanxi Province Coal Geology 115 Prospecting InstituteDatongShanxi 037000China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2021年第95卷第2期

页      面：517-530页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 

基　　金：supported financially by the Science and Technology Major Projects of Shanxi Province of China(grant No.20181101003) the National Key R&D Program of China(grant No.2019YFC1904903) 

主　　题：Kaolinite genesis Carboniferous-Permian Haerwusu Inner Mongolia Autonomous Region 

摘      要：Petrological,mineralogical and geochemical studies carried out on kaolinite deposits in Haerwusu surface mine,Jungar Coalfield,northern Ordos Basin,North China,define their characteristics,ore genesis and economic *** on the crystalline size,two different types of kaolinite rocks,cryptocrystalline and grainy,were identified under the *** data show that kaolinite is the predominant mineral,associated with boehmite,magnesite,anatase,pyrite,diaspore and ***,high boehmite content(mean 70%)shows up in the middle *** minerals present homogeneous shape and a good crystallinity(HI=0.96–1.26).Geochemical studies show that the SiO_(2)/Al_(2)O_(3)molar ratio of kaolinite is close to the theoretical value,and the contents of Na_(2)O,K_(2)O,CaO,Mg O are less,suggesting a strong chemical weathering *** REE and Eu anomalies show a close relationship between kaolinite and the Yinshan Oldland granite.A Ce anomaly reflects a continental sedimentary environment with shallow water.A temperature range of 26.7–34℃was calculated on the basis of the isotopic signatures(δ18O,δD)of the kaolinite *** these data indicate that the formation of the kaolinite is caused mainly by the dissolution,coagulation,precipitation and recrystallization of aluminosilicate clastics in acidic *** formation of boehmite in the middle layers indicates that the source rocks have *** is mainly formed by dehydration and compaction of an aluminum-rich colloid which transported into peat swamp during *** addition,it formed by desiliconization of kaolinite under acidic *** to its high kaolinite content(up to 90%)and low iron mineral content(less than 1%),and good crystallinity,kaolinite deposits occurred at Haerwusu surface mine probably have great economical value in the future.