(1. 中南大学 地球科学与信息物理学院，长沙 410083；
2. 中南大学 有色金属成矿预测教育部重点实验室，长沙 410083；
3. 贵州省有色金属地质和核工业地质勘查局，贵阳 550005)
摘 要: 对黔北务正道地区铝土矿进行层序地层学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。通过探槽和取心井岩心观察以及铝土矿含矿层系样品分析化验资料分析认为，研究区梁山组铝土矿含矿层系为海相和陆相环境沉积，其沉积相类型包括冲积扇、泻湖、湖泊和沼泽。铝土矿含矿层系可划分为3个Ⅰ型层序界面，识别出3个三级层序。每个层序下部的绿泥石岩和铝土岩为海侵体系域沉积，而层序上部的铝土矿则为湖泊相沉积。从含矿层系到栖霞组底部整体为海平面不断上升，沉积相类型也由含矿层系的海相和陆相互层过渡为海相碳酸盐岩沉积。海侵体系域沉积期跨时较短，易于形成冲积扇和泻湖等沉积，岩石类型包括绿泥石岩和铝土岩，而高位体系域跨时较长，绿泥石岩、铝土岩及其风化物能够进行充分的沉积分异作用，从而形成铝土矿，因此，层序格架对铝土矿的形成具有控制作用。
关键字: 沉积型铝土矿；层序地层学；湖泊相；沉积分异；基准面
（1. School of Geosciences and Info-physics, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metallogentic Prognosis, Ministry of Education,
Central South University, Changsha 410083, China;
3. Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou, Guiyang 550005, China）
Abstract:Bauxite distribution law and formation mechanism can be known by sequence stratigraphy analyses of bauxite in Wuzhengdao area, North Guizhou, which can guide exploration of bauxite ore. Based on observation of exploratory trench, cores well and results of sample test, it can be gotten that the main facies of bauxite are marine and continental sedimentary environment, including alluvial fan, lagoon, lake and marsh. Three sequence boundaries of type Ⅰcan be identified, and three sequences can be divided. Chlorite rock and bauxite rock under every sequence deposit in transgressive system tract and bauxite ore upper every sequence deposits in lake. The marine level rises from ore-bearing layer to bottom of Qixia formation (P2q) on the whole, and the facies change from marine and continental facies to marine facies correspondingly. The time is short during deposit of transgressive system tract, and alluvial fan and lagoon develop well. The rock types of transgressive system tract include chlorite and bauxite rock. The time is long during deposit of highstand system tract, and the sedimentary differentiation of chlorite, bauxite rock and its weathered material is carried out fully, which result in forming bauxite ore. So the sequence framework can control the forming of bauxite ore.
Key words: sedimentary type bauxite ore; sequence stratigraphy; lacustrine facies; sedimentary differentiation; base level
