论文部分内容阅读
对黔北铝土矿进行沉积相分析有利于认识铝土矿分布规律和形成机理,可有效解指导将来铝土矿勘探。通过对358m探槽和22口取心井岩心观察以及155块铝土矿含矿层系样品分析化验资料分析认为研究区铝土矿含矿层系为陆相环境沉积,其沉积相类型包括冲积扇相、湖泊相和潮坪相。含矿层序底部的绿泥石岩为冲积扇相沉积,铝土矿和铝土岩为冲积平原上串珠状分布的湖泊相沉积,顶部的炭质页岩为潮坪相潮上带泥沼坪沉积。含矿层系上部的栖霞组为海相碳酸盐岩沉积,所以从铝土矿含矿层系至栖霞组是陆相到海相的沉积过程。实际上,铝土矿就是发育在石炭系黄龙组侵蚀背景下低位期充填沉积,其上的栖霞组为海侵期沉积。另外,低位期的含矿层系又可识别出两期基准面变化,对应铝土矿上、下部的绿泥石岩和铝土岩沉积,而铝土矿则为基准面稳定期绿泥石岩和铝土岩长期沉积分异得到结果。
The analysis of sedimentary facies of Qianbei bauxite is beneficial to understand the distribution rules and formation mechanism of bauxite, which can effectively guide the prospecting of bauxite in the future. Based on the analysis of the core samples of 358m trenches and 22 coring wells and the analysis of 155 samples of bauxite ore-bearing strata, it is considered that the ore-bearing strata of bauxite in the study area are continental facies sediments. The types of sedimentary facies include alluvial fan facies , Lakes and tidal flat phase. The chlorite rocks at the bottom of the ore-bearing sequence are alluvial fan facies, and bauxite and bauxite are beaded sediment-lacustrine sediments. The top carbonaceous shale is mudflat sediments on the tidal flat . The Qixia Formation in the upper part of the ore-bearing system is marine carbonate sediments, so the sedimentary process from continental to Qixia Formation is continental to marine. In fact, bauxite was developed during low-stage filling and deposition in the Carboniferous Huanglong Formation, and the Qixia Formation on this area was transgressive sedimentation. In addition, the low-level ore-bearing strata also identified two changes in the basement corresponding to the upper and lower bauxite deposits of chlorite and bauxite, while the bauxite is the reference stable chlorite And bauxite long-term deposition differentiation results.