摘要
在论述黔北务正道地区铝土矿成矿地质背景的基础上,根据古盐度(B)质量分数显示和古地貌特征,认为研究区北部的道真一带是一个"十字形"的半封闭式的古海湾沉积环境,南部属陆上沉积环境。相带划分表明:以滨海相沉积环境下形成的铝土矿矿石品质较好,以中高铝、中高铝硅比为特征;形成于滨岸湿地相的铝土矿次之,矿石品质以中铝、中铝硅比为特征;形成于坡积相的铝土矿矿石品质欠佳,以低铝、低铝硅比为特征。由坡积相向滨岸湿地相过渡的铝土矿矿石品质逐渐变富;而滨海相中铝土矿在其中心地带品质好,向浅海相过渡其矿石品质逐渐变贫。铝土矿矿石品质的规律变化,反映了研究区铝土矿的赋存富集严格受沉积相的制约而呈环状、条带状分布的特点。
Ore layers of bauxite deposits from the Wuchuan-Zheng＇an-Daozhen area in the northern Guizhou Province, occur in the Middle to Upper Dazhuyuan Formation with a timing age of Early Permian. Based on paleosalinity by B contents and paleogeomorphology analysis of the ore-host strata, it is suggested that the northern half in geomorphology was a cross-shaped semi-enclosed bay, whereas southern half was con- tinental marginal environment along the coast. It is shown that ore grades of the bauxites are closely corre- lated with their sedimentary facies. Bauxitic ores formed at coastal facies environment have higher A12Oa content and A/S ratio than those formed at alluvial plains, whereas ores in slope sedimentary facies display lowest A12Oa content and A/S ratio. These infer ore-grade increase trends from talus-to alluvial plains faeieses, and from transitional-to coastal sea facieses. The bauxitic ores in the area show ringlike or band shapes, which fur- ther indicates a close relationship between bauxitic ore grade and sedimentary facies.
出处
《地质科技情报》
CAS
CSCD
北大核心
2013年第1期19-22,共4页
Geological Science and Technology Information
基金
贵州省地勘基金项目"贵州务正道地区铝土矿基础地质和成矿规律研究"
关键词
铝土矿
矿石品质
沉积相
务正道
黔北
bauxite deposit
ore grade
sedimentary facies
Wuchuan-Zheng＇an-Daozhen area
northernGuizhou Province
