豫西偃龙煤田深部铝土矿地质特征及矿床成因

Geological Characteristics and Genesis of the Deep-Seated Bauxite Beneath the Yanlong Coalfield in Western Henan Province

偃龙煤田深部铝土矿区位于豫西铝土矿成矿区嵩箕铝土矿成矿小区,是豫西铝土矿成矿区的重要组成部分。区内铝土矿赋存于上石炭统本溪组中上部,下伏具有岩溶特征的寒武—奥陶纪灰岩,沉积相为滨岸泻湖泥岩相区,属海相沉积的一水硬铝石岩溶型矿床,矿体主要填充在岩溶作用形成的负地形之中。本文系统阐述了矿区的含矿岩系、矿床地质及矿石质量特征等,研究了本区铝土矿的成矿地质条件、矿床的展布规律和富集规律,对矿床成因及控矿因素进行了分析,指出铝土矿床分布在坳陷区边部及隆起区的过渡带,铝土矿的厚度和品质与本溪组厚度有着明显的正相关关系,预测深部仍有较好的成矿远景。

The deep-seated bauxite deposit beneath the Yanlong coalfield lies in the Songji bauxite mineralization area of western Henan bauxite min- eralization area,which is an important component of the West Henan bauxite mineralizatiou district. The bauxite occurs in the middle-upper part of the upper carboniferous series Benxi Formation,underlain by the Cambrian -ordoviciau limestone with karst characteristics. The sedimentary tacies is coastal lagoon mudstone, belonging to diaspore type karst ore deposit in a marine setting. The ore body mainly occurs in the karst terrain. This paper describes the ore-bearing rock system,ore deposit geology and ore features of this area, discusses the metallogenic geological setting, the distribution and enrichment processes of the bauxite ,and analyses the ore genesis and ore-controlling factors. The research results suggest that this bauxite was generated in a transitional zone between the marginal depression and uplifted area, where the thickness and quality of bauxite are positively correlated with the thickness of the Benxi Formation. It is forecasted that a good prospect of mineralization exits at depth beneath this area.