摘要
河南省新安县石寺-北冶地区铝土矿属典型的古风化壳沉积型铝土矿,矿体赋存于上石炭统本溪组。为研究该铝土矿及其基底碳酸盐岩及北秦岭伏牛山岩体的地球化学特征,对钻孔内3件铝土矿样品及3件含铝岩系基底碳酸盐岩样品进行了稀土元素测试,并结合碎屑锆石年代学研究成果,讨论铝土矿成矿物质来源。SiO_(2)-Al_(2)O_(3)-Fe_(2)O_(3)三元图解显示,研究区铝土矿样品主要元素平均值均落在铝土矿和高岭石型铝土矿范围内,均经历了强烈红土化过程。区内含矿岩系B含量普遍较高,基底碳酸盐岩样品中B含量也非常高,尤其是钙质页岩中B含量高达370×10^(-6),说明基底岩石可能为含矿岩系的形成提供了一定的物质来源。11个铝土矿样品与3个基底碳酸盐岩样品及伏牛山岩体的稀土元素配分曲线具有一定相似性,又有明显的区别。伏牛山岩体和基底碳酸盐岩的轻重稀土分馏更明显,重稀土分馏也较明显,铝土矿、基底碳酸盐岩、伏牛山岩体的δEu平均值分别为0.56、0.62、0.64,均表现出较为明显的Eu负异常。根据稀土元素特征,并结合碎屑锆石年代学的研究成果,认为研究区基底碳酸盐岩和北秦岭造山带加里东期、晋宁期火成岩及前寒武纪变质岩共同为新安县石寺-北冶地区铝土矿提供了成矿物质来源。
The bauxite deposit in the Beiye-Shisi area of Xin'an County,Henan Province is a typical karst bauxite deposit,and the ore bodies occur in the Upper Carboniferous Benxi Formation.This work tested rare earth elements of three bauxite samples and three base rock samples of aluminous rock series in the borehole,in an attempt to discuss the geochemical characteristics of bauxite and its basement carbonate rocks and the Funiushan pluton in North Qinling.In combination with detrital zircon geochronology,the source of ore-forming materials was also discussed.The ternary diagram of SiO_(2)-Al_(2)O_(3)-Fe_(2)O_(3)shows that the average values of the main elements of bauxite samples all fall in the range of bauxite and kaolinite type bauxite,and all experienced strong laterization process.The B content of ore-bearing rock series in the study area is generally high,and that of basement carbonate rocks samples is also very high,especially the B content of calcareous shale is up to 370×10^(-6).It is inferred that basement carbonate rocks may provide certain material source for the formation of ore-bearing rock series.The rare earth elements distribution curves of 11 bauxite samples and three basal limestone samples share some similar patterns with the Funiushan pluton,and also display distinct difference.The light-heavy REE fractionation is evident for the Funiushan pluton and basal limestone,and their heavy REE fractionation is also obvious.The averageδEu of bauxite,basement carbonate rocks and Funiushan pluton is 0.56,0.62 and 0.64,respectively,all showing negative Eu anomaly.Based on the characteristics of rare earth elements and detrital zircon geochronology,it is considered that the basement carbonate rocks in the study area,Caledonian and Jinning igneous rocks and Precambrian metamorphic rocks in the North Qinling orogenic belt all provide the source of ore-forming materials for the bauxite deposits in the Shisi-Beiye area of Xin'an County.
作者
刘海鹏
陈磊
李军旗
李钢
董寒杰
豆靖林
LIU Haipeng;CHEN Lei;LI Junqi;LI Gang;DONG Hanjie;DOU Jinglin(The 1 st Team of Henan-Nonferrous Metals Geological Survey,Zhengzhou,Henan 450016;Henan Nonferrous Metal Mineral Exploration Engineering Technology Research Center,Zhengzhou,Henan 450016)
出处
《地质与勘探》
CAS
CSCD
北大核心
2022年第2期247-257,共11页
Geology and Exploration
基金
中国地质调查局河南省新安石寺-北冶地区铝土矿调查评价项目(编号:1212011120774)、河南省地质勘查基金项目(豫国土资发(2013)7号、豫国土资发(2014)3号、豫国土资发(2013)7号、豫国土资发(2016)46号和豫自然资函[2019]373-5)联合资助。
关键词
铝土矿
成矿物质来源
古风化壳沉积型
石寺-北冶地区
新安县
河南省
bauxite
source of ore-forming materials
paleo-weathering crust sedimentary type
Shisi-Beiye area
Xin'an County
Henan Province
