河南登封市三元—白坪铝土矿床地质特征及矿床成因

Geological characteristics and genesis of Sanyuan-Baiping bauxite deposit in Dengfeng City of Henan

河南省登封市三元—白坪铝土矿区位于华北陆块南缘,属于河南省铝土矿四级成矿区偃师—巩义—荥阳—登封—新密矿带,为河南省富铝土矿集中区。区内褶皱构造不发育,以断裂构造白坪正断层为主,地层出露简单。通过本次地质勘查工作,全区发现并控制铝土矿体6条,主要分布于古岩溶凹陷中,呈似层状、透镜状、漏斗状。铝土矿产于寒武系碳酸盐岩古风化侵蚀面上,赋存在中石炭统本溪组内,矿床成因为沉积型一水硬铝石铝土矿床。本区矿体受古地形严格控制,白坪凹陷为寻找沉积型铝土矿床的有利地段,赋矿层中石炭统本溪组亦是寻找铝土矿较好的找矿标志层。

Sanyuan-Baiping bauxite mining area in Dengfeng City is located in the south margin of the North China block,which belongs to the fourth-level bauxite metallogenic zone of Yanshi-Gongyi-Xingyang-Dengfeng-Xinmi ore belt in Henan Province.It is a rich bauxite deposit concentrated area in Henan Province.The fold structure is not developed in the area,the fault structure is mainly Baiping normal fault,and the strata are exposed simply.The Middle Carboniferous Benxi Formation is the bauxite ore-bearing layer in the area.Through the geological exploration work,six bauxite orebodies,appearing as layered,lens-shaped and funnel-shaped,have been discovered and controlled in the whole area,mainly distributed in the paleokarst depression.The bauxite orebodies are located on the paleoweathered erosion surface of the Cambrian carbonate rocks,and are hosted in Benxi Formation of the Middle Carboniferous.The deposit is a sedimentary monohydrate diaspore bauxite deposit.The orebodies in this area are strictly controlled by paleotopography,and Baiping depression is a favorable area to explore for the sedimentary bauxite deposit.As the ore-bearing layer,Benxi Formation of the Middle Carboniferous is also a good prospecting marker for the bauxite deposit.