陕西勉县庙坪石墨矿床地质特征与成因初步探讨

Geological Characteristics and Genesis of the Miaoping Graphite Deposit in Mian County of Shaanxi Province

新发现的勉县庙坪石墨矿床位于南秦岭勉略缝合带,目前已圈定11条以石墨矿化为主、并伴生钒、钼、钛的矿化带,15条矿化体。该矿床赋存于志留系中统舟曲岩组上岩段炭质板岩及粉砂岩中。本文在成矿地质背景、矿床特征、钻孔岩芯化学分析、矿石矿物赋存状态及特征的研究基础上,对矿床的成因进行了初步的探讨。研究表明,含矿岩性主要为含石墨黑云母变粒岩,其中伴生的钒与固定碳呈明显的正相关,石墨中的碳质来源为生物有机碳,矿床成因为沉积变质型矿床,具有层控后期热液变质的基本特征。

The newly discovered graphite ore deposit in Miaoping,Mian county is located in the Mian-Lue suture zone of the southern Qinling Mountains. So far 11 zones and 15 bodies of mineralization have been delineated,which are dominated by graphite with associated vanadium,molybdenum,and titanium. This deposit occurs in carbonaceous slate and siltstone of the Zhouqu rock group of the middle Silurian System. This paper was on the basis of the metallogenic geological background,ore deposit characteristics,analysis of ores in drilling cores,ore mineral occurrence state and ore characteristics. The objective is to explore the genesis of this deposit. Research shows that the ore-bearing rocks include biotite-granulite where the concomitant vanadium is positively correlated with the fixed carbon in graphite. The carbon in graphite is from biological organic carbon. The genesis of this deposit belongs to sedimentary metamorphic type,which possesses basic characteristics of layer-controlled late hydrothermal metamorphism.