豫西宜阳地区煤下铝土矿成矿规律及找矿标志

Metallogenic regularity and prospecting indicators of bauxite under coal in Yiyang area,Western Henan

宜阳煤下铝土矿床位于华北地台南缘,其南紧接崤山—鲁山拱斜断束、北紧接为洛阳新坳陷。通过对成矿地质条件及控矿因素分析后认为,该矿床的铝土矿赋存于上石炭统本溪组(二叠系煤系之下);其厚大矿体位于盆地基底的次级凹陷中,矿体的厚度、品位与含矿岩系的厚度呈正相关;铝土矿的成矿物质来源于古陆,古陆盆地边缘存在的低山丘陵地貌有利于铝硅分离化学风化作用的进行和铝土矿的形成;含铝岩层及地层、岩相古地理特征、共生矿物标志可作为本区的找矿标志。

The bauxite under coal in Yiyan area is located in the southern margin of the North China platform,which is close to the Xiaoshan-Lushan arch oblique fault bundle in the south and the new depression in Luoyang in the north.On the basis of metallogenic geological conditions and ore-controlling factors analysis,it is considered that the bauxite deposit is hosted in the Upper Carboniferous Benxi Formation(under the Permian coal measures).The thick and large ore bodies are located in the secondary depression of the basin basement.The thickness and grade of the ore bodies are positively correlated with the thickness of the ore-bearing rock series.The ore-forming materials of bauxite are derived from the ancient land.The low hilly landform on the edge of the ancient land basin is conducive to the chemical weathering of aluminum-silicon separation and the formation of bauxite.Aluminum-bearing rock formation and strata,lithofacies paleogeographic characteristics,symbiotic mineral markers can be used as prospecting indicators in this area.