湖北中部中二叠世梁山组铝土岩沉积期岩相古地理环境与成矿规律研究

Study on Lithofacies,Paleogeography and Mineralization Regularity of Liangshan Formation,Middle Permian Epoch in Central Hubei Province

湖北省保康—南漳—宜城一带中二叠世梁山组是省内沉积型铝土矿重要产出层位,通过岩性、岩相及含矿特征研究,查明含矿岩系沉积特征明显受古陆—滨海岩相古地理条件控制,主要为无障壁海岸环境,自北向南依次沉积后滨、前滨和临滨相。铝土矿是因富铝古陆经风化、搬运和分选作用,于较平坦的后滨环境沉积形成,具不稳定性沉积特点。

The Liangshan Formation of middle Permian,outcropped in Baokang,Nanzhang and Yicheng counties,is an important stratum for the formation of sedimentary bauxites. By the study on their rock types,lithofacies and ore-bearing potentiality,the authors conclude that the sedimentary characteristics of the ore-bearing stratum were clearly influenced by the conditions of old land-coastal lithofacies and paleography. It was mainly an environment of barrier-less coastal area,where the backshore,foreshore and nearshore were developed from north to south. The bauxite was formed in the flat backshore by the erosion,transportation and deposition of the aluminum-rich minerals from the old land,had the characteristic of unstable deposition.