地质学报2018，Vol.92Issue(3)：587-603,17.
西澳Darling Range地区红土型铝土矿地球化学特征及源区研究
Geochemical Characteristics and Source of the Laterite-type Bauxite Deposit in Darling Range, Western Australia
摘要
Abstract
Located in western Australia,Darling Range is rich in laterite-type bauxite resources.In order to understand metallogenesis of the laterite-type bauxite in Darling Range and constrain the source of oreforming materials,this study carried out element geochemistry analysis and LA-ICP-MC dating of detrital zircons from bauxite and underlying granite.The results show that the bauxite in the Darling Range are composed mainly of Al2O3,Fe2O3,SiO2,and TiO2.Al2O3 has a negative relationship with SiO2,but a positive relationship with TiO2.It suggests that bauxite experienced the loss of Si and enrichment of A1 and Ti during the ore-forming process.Geochemical analysis shows that the bauxite is enriched in Th,U,Nb,Ta,Zr,Hf and Ti,and depleted in Ba,K,Sr,P and Sm.The bauxite is characterized by low REE contents from 1.36 × 10-6 to 65.58× 10-6,and the chondrite-normalized REE pattern slightly tilts to the right and shows enrichment in LREE.LA-ICP-MC detrital zircon U-Pb ages of the bauxite can be assigned to two groups:1167～1267 Ma (2 zircons) and 2539～2696 Ma (16 zircons).The former younger detrital zircons possibly came from Albany-Fraser orogeny,while the later older detrital zircons have the weighted average ages of 2579±15 Ma (MSWD=1.16),consistent with 2585±12 Ma (MSWD=0.83) of Archean granite,with the difference within the error.This indicates that besides the zircons from Archean granite,minor zircons in the laterite-type bauxite may derive from Albany-Fraser orogeny belt.Using Al2O3/TiO2 ratio,lgCr-lgNi plot,trace element ratios,and REE pattern to trace the source of laterite-type bauxite deposit,it can be concluded that Archean granite is the major source of ore-forming materials for the laterite-type bauxite deposit in the Darling Range of western Australia.关键词
西澳/Darling Rang地区/铝土矿/U-Pb年代学/地球化学/源区研究Key words
western Australia/Darling Range/bauxite/U-Pb geochronology/geochemistry/source引用本文复制引用
孙朋飞,江思宏,韩宁..西澳Darling Range地区红土型铝土矿地球化学特征及源区研究[J].地质学报,2018,92(3):587-603,17.基金项目
本文为国家地质大调查项目(编号1212011120325和121201103000150006)资助的成果. （编号1212011120325和121201103000150006）
