REE Tetrad Effect as a Powerful Indicator of Formation Conditions of Karst Bauxites: A Case Study of the Shahindezh Deposit, NW Iran

作     者：Ali ABEDINI Mansour REZAEI AZIZI Ali Asghar CALAGARI 

作者机构：Department of GeologyFaculty of SciencesUrmia University*** UrmiaIran Department of Earth SciencesFaculty of Natural SciencesUniversity of Tabriz*** TabrizIran 

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

年 卷 期：2019年第93卷第4期

页      面：912-927页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported financially by the Research Bureau of Urmia University 

主　　题：Geochemistry REE Tetrad effect Karst bauxite Shahindezh Iran 

摘      要：Study of the concentration of major,trace,and rare earth elements(REE)in the Shahindezh karst bauxite deposit,northwestern Iran clarifies the relationship of the tetrad effect with geochemical parameters in the bauxite *** existence of irregular curves in the chondrite-normalized REE patterns as well as non-CHARAC behavior of geochemically isovalent pairs(Y/Ho)are related to the tetrad *** meaningful positive correlation between the sizes of the calculated T3 tetrad effect and some geochemical factors such as Y/Ho,ΣREE,La/Y,(La/Yb)N,and(LREE/HREE)N as well as some major oxides-based parameters like Al2O3+LOI/SiO2+Fe2O3,Al2O3/Fe2O3,Al2O3+LOI,IOL,and SiO2+Fe2O3indicate that the studied bauxite horizon was likely deposited by different(acidic and/or alkalic)solutions at different *** lower part of the studied horizon with a thickness of^4.7 m displays alkali characteristics whereas the upper parts of the horizon with a thickness of^5.3 m are characterized by more acidic *** results are fully supported by the co-occurrence of convex-concave tetrad effect curves in the chondrite-normalized REE ***,the tetrad effect phenomenon used in this study has proved to be a good and reliable geochemical proxy to assess the conditions of the depositional environment in the Shahindezh bauxite ores.