海南岛王五—文教深大断裂带西南侧加来地区铷元素地球化学特征

Geochemical characteristics of Rb in the Jialai area on the southwest side of the Wangwu-Wenjiao deep fracture zone in Hainan Island

本文以华南褶皱系五指山褶皱带北部加来地区地质特征为基础,进一步研究水系沉积物地球化学特征、土壤地球化学特征、岩石化学特征和矿物化学特征,探讨铷元素地球化学特征及其成因。研究表明:研究区内铷元素的水系沉积物异常、土壤地球化学异常、花岗岩类岩石化学特征和矿物化学特征基本吻合;本区花岗岩类中铷元素背景值普遍较高,但不同时期花岗岩类中铷元素背景值不一,中三叠世红岭花岗岩体中铷元素背景值最高;矿物原位LA-ICP-MS微量元素分析结果显示,花岗岩类中钾长石、白云母和黑云母是Rb 2O的主要载体矿物。

Based on the geological features of the Jialai area in the north Wuzhishan fold belt of the south China fold system the paper studies the geochemical characteristics of stream sediments,soil geochemical characteristics,petrochemical characteristics and mineral chemistry characteristics then dicusses the geochemical characteristics of Rb and the genesis.Results show that stream sediment anomaly,soil geochemical anomaly of Rb are basically coicided with characteristics of granitoid petrochemistry and mineral chemistry.The background value of Rb of granitoid in the study area is generally high but different with granites formed in different times.The highest background value of Rb is for the Middle Triassic Hongling granitic pluton in this area.LA-ICP-MS trace elements analysis of in-situ-minerals show that K-feldspar,muscovite and biotite in the granitoid are the main carrier minerals of Rb 2O.