海南省罗葵洞钼矿围岩蚀变找矿标志

WALLROCK ALTERATION AND PROSPECTING CRITERIA OF THE LUOKUIDONG MOLYBDENUM DEPOSIT IN HAINAN PROVINCE

海南省罗葵洞钼矿是一处特大型斑岩型钼矿床,赋存于陆相火山岩与隐伏似斑状花岗岩接触界面及其外围,呈隐伏状产出,地表很难见到钼矿化露头.矿区最常见的蚀变是硅化和黄铁矿化,其次有钾化、绢云母化、绢英岩化、云英岩化、伊利石-水白云母化、黑云母化、绿帘石化、次闪石化、绿泥石化、碳酸盐化等,局部尚有叶腊石化、萤石化.其中硅化、钾化、绢英岩化、云英岩化与钼矿成矿关系密切.据初步研究,该区蚀变从火山口相中心,由内向外大致可分为不十分明显的4个蚀变带:强硅化蚀变带、硅钾蚀变带、硅化蚀变带、绿帘石-绿泥石化带.在详查工作中根据面形硅化细脉带,可以确定矿化范围,钾化强烈发育地段为钼矿富集部位.

The Luokuidong molybdenum deposit in Hainan Province, occurring in and around the contact between continental volcanic rocks and concealed porphyraceous granite, is of a large sized porphyry-type one. The deposit is concealed, with rare molybdenum mineralization outcrop in the surface. The most common alterations in the orefield are silicification and pyritization, followed by potassic alteration, sericitization, phyllic alteration, greisenization, illidromica alteration, biotitization, epidotization, uralitization, chloritization and carbonation, locally with pyrophyllitization and fluoritization, among which, the silicification, potassic alteration, phyllic alteration and greisenization are closely related to the molybdenum mineralization. Preliminary study shows that, outwards from the central crater facies, the alterations in the area can be roughly divided into four unclear zones： strongly silicified alteration zone, siliceous and potassic alteration zone, silicified alteration zone and epidotization-chloritization zone. In the detailed survey work, the scope of mineralization can be determined by the silicified veinlets on the surface. The areas with strong potassic alteration are always the Mo-enriched positions.