贵州务川瓦厂坪铝土矿床地球化学特征

务川瓦厂坪铝土矿床是近年探明的大型矿床,332+333资源量4397万吨.地球化学研究显示,矿床中Al_2O_3与TiO_2含量成正相关关系,与SiO_2含量成负相关关系;硫同位素组成属于沉积岩范畴,总体显示出变化范围大(-29.20‰～+12.40‰),反映出复杂的成矿环境和轻重硫同位素的多次分离;不同岩、矿石的稀土总量(∑REE)含量变化大,LREE/HREE均大于1,显示轻稀土较富集;铝土矿层中,土状铝土矿稀土元素含量相对高,致密块状铝土矿含量相对低,稀土元素含量与矿石质量总体呈正相关关系.铝土矿层及志留系韩家店组的稀土总量含量较接近.矿床成因属古风化壳沉积型.

The Geochemical Chareacteristics of Wachangping Bauxite Deposite in Wuchuan County,Guizhou Province, China

Wachangping Bauxite deposit is the biggest deposit currently in the area, and has been explored 43970000 tons of resources ( 332 + 333 ). Geochemical characteristics show that there is a positive correlation between the con-tents of Al_2O_3 and TiO_2, but a negative correlation between the contents of Al_2O_3 and SiO_2 in the bauxite deposits. The composition of sulfur isotopes has sedimentary characteristics with a great variety ( -29. 20‰～ + 12.40‰) , re-flecting the complicated metallogenic environment and multi separations. Contents of ΣREE vary greatly in different rocks and ores, with all LREE/HREE > 1, showing LREE richer than HREE. In the bauxite layer, content of soil like REE is high, but content of dense REE is low. There is a positive correlation between REE contents and quali-ties of the bauxite ore. REE content in the bauxite layer is almost same with that in the lower-middle Silurian Hanjia-dian group (S_(1-2)hj). Deposit genesis belongs to ancient efflorescent shell sedimentary.