湖南省沅陵县桥头钒矿地质特征、控矿因素及成矿浅析

Geological Characteristics, Ore-Controlling Factors and Metallogenesis of Qiaotou Vanadium Deposits in Yuanling County in Hunan Province

桥头钒矿是近年查明的一个中-大型钒矿床,位于扬子准地台中段南缘,钒矿体赋存于寒武系下统牛蹄塘组底部一套富含有机质的黑色岩系中,岩性主要为硅质炭质板岩、炭质板岩、黑色页岩,炭质、硅质含量越高,钒品位往往越高,矿体厚度大,连续性好,地层、岩性控矿作用明显。通过对桥头钒矿成矿地质背景、矿床地质特征、控矿规律的分析,初步认为:在寒武纪缺氧大环境下,钒被粘土质、有机质吸附,后因环境变化以类质同象形式取代Al3+,进而形成含钒的矿物。在钒的形成过程中生物地球化学作用起着主导作用,因此将桥头钒矿归属为化学沉积与生物地球化学沉积成因。

The Qiaotou vanadium deposit is a medium-large vanadium deposit identified in recent years.It is located in the southern margin of the middle section of the Yangtze River.The vanadium ore body is located in the black rock series rich in organic matter at the bottom of the Cambrian Niutitang Formation.The lithology is mainly composed of siliceous carbonaceous slate,carbonaceous slate and black shale.The higher the siliceous content,the higher the vanadium grade,the larger the ore body thickness,the better continuity,and the stratum and lithology control effect.Based on the analysis of the ore-forming geological background,geological characteristics and ore-controlling rules of Qiaotou vanadium ore,it is preliminarily believed that in the Cambrian anoxic environment,vanadium is adsorbed by clay and organic matter,and then the environmental similarity is similar.Form replaces Al3+to form vanadium-containing minerals.Biogeochemistry plays a leading role in the formation of vanadium,so the bridgehead vanadium ore is attributed to chemical deposition and biogeochemical deposition.