中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2015年
1期
179-189
,共11页
沉积型铝土矿%层序地层学%湖泊相%沉积分异%基准面
沉積型鋁土礦%層序地層學%湖泊相%沉積分異%基準麵
침적형려토광%층서지층학%호박상%침적분이%기준면
sedimentary type bauxite ore%sequence stratigraphy%lacustrine facies%sedimentary differentiation%base level
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。
對黔北務正道地區鋁土礦進行層序地層學分析有利于認識鋁土礦分佈規律和形成機理,可有效解指導將來鋁土礦勘探。通過探槽和取心井巖心觀察以及鋁土礦含礦層繫樣品分析化驗資料分析認為,研究區樑山組鋁土礦含礦層繫為海相和陸相環境沉積,其沉積相類型包括遲積扇、瀉湖、湖泊和沼澤。鋁土礦含礦層繫可劃分為3箇Ⅰ型層序界麵,識彆齣3箇三級層序。每箇層序下部的綠泥石巖和鋁土巖為海侵體繫域沉積,而層序上部的鋁土礦則為湖泊相沉積。從含礦層繫到棲霞組底部整體為海平麵不斷上升,沉積相類型也由含礦層繫的海相和陸相互層過渡為海相碳痠鹽巖沉積。海侵體繫域沉積期跨時較短,易于形成遲積扇和瀉湖等沉積,巖石類型包括綠泥石巖和鋁土巖,而高位體繫域跨時較長,綠泥石巖、鋁土巖及其風化物能夠進行充分的沉積分異作用,從而形成鋁土礦,因此,層序格架對鋁土礦的形成具有控製作用。
대검북무정도지구려토광진행층서지층학분석유리우인식려토광분포규률화형성궤리,가유효해지도장래려토광감탐。통과탐조화취심정암심관찰이급려토광함광층계양품분석화험자료분석인위,연구구량산조려토광함광층계위해상화륙상배경침적,기침적상류형포괄충적선、사호、호박화소택。려토광함광층계가화분위3개Ⅰ형층서계면,식별출3개삼급층서。매개층서하부적록니석암화려토암위해침체계역침적,이층서상부적려토광칙위호박상침적。종함광층계도서하조저부정체위해평면불단상승,침적상류형야유함광층계적해상화륙상호층과도위해상탄산염암침적。해침체계역침적기과시교단,역우형성충적선화사호등침적,암석류형포괄록니석암화려토암,이고위체계역과시교장,록니석암、려토암급기풍화물능구진행충분적침적분이작용,종이형성려토광,인차,층서격가대려토광적형성구유공제작용。
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 typeⅠcan 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.