福建建宁东坑铷矿地质特征及成因分析

Geological Characteristics and Genesis of the Dongkeng Rubidium Deposit in Jianning,Fujian Province

建宁东坑矿区铷矿(化)体主要贮存于石英斑岩脉及其与围岩接触带附近,受北东向断裂控制,倾向北西,产状陡立。容矿岩石主要为石英斑岩,次为碎裂岩、花岗斑岩。铷矿化与硅化、绢云母化关系密切,主矿体中Rb_2O平均品位为0.13%,目前控制Rb_2O资源量为1.3×10~4 t,达大型规模。分析显示,铷元素主要以类质同象贮存于蚀变白云母、蚀变黑云母中。天井坪(岩)组变粒岩和加里东期混合岩中含量较高的铷、锡元素为东坑矿区提供了丰富的成矿物质来源,后燕山期强烈的岩浆热液活动使这些岩石中的铷、锡元素部分活化、富集,形成东坑铷锡矿床,属于岩浆热液成因矿床。

Dongkeng mine of rubidium ore body mainly occurs in the quartz porphyry and the sur- rounding rock near the contact zone, Controlled by NE trending faults, North Westdipping, the occurrence of steep. The ore hosting rocks are mainly quartz porphyry, followed by eata- elastic rock and granite porphyry. Rubidium mineralization is closely related to silicification and sericitization. The average grade of Rb20 is 0. 13%. At present, the amount of control resources is 13 thousand tons, up to large scale. The analysis shows that the main elements of Rh as the isomorphism exists in the alteration of muscovite and biotite. The Tianjingping rock of the granulite and the Caledonian mixed rocks provides a rich source of ore-forming material for Dongkeng mine. After the strong magmatic hydrothermal activity in Yanshan period, the Rb and Sn elements in these rocks were partially activated and enriched, formed the Dongkeng rubidium tin deposit which belong to magmatic hydrothermal deposit.