STUDY ON THE GEOLOGY AND ORE-CONTROLLING CONDITIONS OF THE BAUXITE DEPOSITS IN SANMENXIA AREA, HENAN PROVINCE

The bauxite deposits in Sanmenxia area, Henan Province, are of diasporic sedimentary type formed on Ordovician limestone. The forms of bauxite orebodies are closely related to the paleokarst erosion surface, occurring as stratiform-stratoid, lentiform (podiform) and doline form, which are strictly controlled by paleotopography. The ore types are mainly rudaceous, gravelly, alveolar, pisolitic and compact bauxites, and the composite types as well. The forming of deposits is controlled by multiple conditions mainly as strata of Benxi Formation, structure and paleogeography.