桂西北超微粒浸染型金矿成矿地质条件及找矿模式

THE METALLOGENETICALLY GEOLOGICAL CONDITIONS ANDPROSPECTING MODEL OF THE SUPER MICROGRAINEDDISSEMINATED-TYPE GOLD DEPOSITSIN NORTHWESTERN GUANGXI

桂西北地区超微粒浸染型金矿形成的地质条件：①桂西坳陷中的隆起区边缘是成矿的地质构造前提条件，其中发育基底断裂活动带是先决条件；②有利的布矿构造系统是矿床、矿体就位的重要控制因素；③有利的层位、岩性组合和岩石特征是矿体就位和矿化强弱的重要控制条件；④同生构造是有利的附加条件；⑤晚古生代中基性海底火山喷溢是必要条件，印支燕山期岩浆活动是有利因素；⑥表生氧化淋滤和富集及保存是主要因素。基于此明确了找矿条件，另外据矿化特征和主要矿物成因及找矿矿物学研究确定了找矿标志，最后建立了找矿模式。

he metallogenetically geological conditions of the super micrograined disseminated-type golddeposits in northwestern Guangxi are as follows: 1) The marginal zone of upwarping area ofWestern Guangxi depoession is the metallogenetic premise condition of geological structure. Amongthe condition, the active belt of foundational fault in the zone is the precondition．2) The favourableore-preserving structural system is an important control factor for the emplacement of depoits andorebodies. 3) The favourable horizons, lithologic association and petrologic characteristics are majorcontrol conditions for the emplacement of ore bodies and mineralization intensity. 4) The syngeneticstructurei is the favourable additional condition ,5) Late Palaeonzoic intermediate-hasic cubmarinevolcanic eruption is the necessary condion, and Indosinian and Yanshanian magmatism is thebeneficial factor. 6) Superficial oxidation leaching, enrichment and preservation are importantfactors. On the basis of these, prospectingcondions are clear. In addition, prcopecting criteria aredefined in the light of the mineralization characteristics, the genesis of essential minerals andprespecting mineralogy in gold depeits. Finally, prcopecting model is established.