河南渑池铝土矿成矿区地球化学背景

摘 要]地球化学元素的分布特征反映了元素矿化富集规律。本文在了解矿床地质背景及地球化学性质的基础上,通过对河南渑池地区水系沉积物地球化学测量数据的统计分析,着重研究铝土矿成矿区的地球化学背景,寻找地球化学找矿指标,希望对以后的勘察工作有所借鉴。研究区的铝土矿带位于石炭系本溪组地层中,且本溪组不整合覆盖于奥陶纪地层之上。与上层地层相比,矿层富含Al₂O₃、高场强元素(HSFS),尤其是硼元素。对水系沉积物地球化学数据进行分析,得出反映元素分布形态的地球化学图,结果表明,只有B 元素可以明确反应铝土矿的空间分布位置。矿床点一般沿硼元素高值区边界分布,表明B 元素可以作为河南渑池铝土矿成矿区的地球化学找矿指标。

Geochemical Background of the Mianchi Bauxite Mineralization area, Henan Province

Abstract:Spatial distribution of the ore-forming elements reflects their enrichment regularity. Based on studies of the geological setting and geochemical characteristics of the ores, this paper studies the geochemical background of the Mianchi bauxite area in Henan Province to provide guidance for the future exploration work. The bauxite occurs in the Middle Carboniferous Benxi Formation, which overlies the unconformity upon the Middle Ordovician. The ores are enriched in A₂O₃, HSFE, especially in element of B, compared with the upper crust. Geochemical maps based on element concentrations of stream sediment samples reveal that only element of B can denote the locations of the bauxite deposits. The ore deposits generally surround the margin of the area with high boron concentration. It is shown that the boron can serve as the geochemical indicator for searching for bauxite deposits.