内蒙古中部大黄花夕卡岩型铜多金属矿床特征

MINERALOGICAL CHARACTERISTICS OF DAHUANGHUA COPPER POLYMETALLIC DEPOSIT IN CERTRAL INNER MONGOLIA

大黄花铜多金属矿位于赤峰-朝阳金多金属成矿带南部,矿化发生在燕山期正长花岗岩与石炭系酒局子组大理岩接触部位,局部构成铜(铁)矿体.夕卡岩矿物主要为石榴石、透辉石、透闪石、绿帘石、绿泥石、角闪石及阳起石,金属矿物有黄铜矿、辉铜矿、黝铜矿、斑铜矿、铜蓝及氧化次生矿物蓝铜矿、孔雀石、褐铁矿.围岩蚀变强烈,呈现清晰的蚀变分带现象,自接触带向外可分为较强的透闪石-阳起石化带,较强的透闪石-透辉石化带,弱蚀变的大理岩化带.金属元素组合特征明显,为Cu、Pb、Zn、Au、Ag组合.该铜多金属矿的形成与正长花岗岩的侵入作用有关,成矿时代为中侏罗世晚期,与朝阳-赤峰地区金多金属矿成岩成矿时代一致.

The Dahuanghua Cu-polymetallic deposit is located in the south of Chifeng-Chaoyang Au-polymetallic metallogenic belt.The mineralization is occurred in the contact between Yanshanian syenogranite and Carboniferous Jiujuzi marble with Cu/Fe orebodies formed locally.The skarn minerals are mainly composed of garnet,diopside,tremolite,epidote,chlorite,hornblende and actinolite;while the metal minerals include chalcopyrite,chalcocite,tetrahedrite,bornite,covellite and oxidized secondary minerals such as azurite,malachite and limonite.The wall rock alteration is intensive,presenting a clear zonation:strongly-altered tremolite-actinolite zone,strong tremolite-diopside alteration zone,and weakly-altered marble zone outwards from the contact zone.The metallic element association of Cu-Pb-Zn-Au-Ag is obvious.This Cu-polymetallic deposit was formed in the late period of Middle Jurassic and related to the intrusion of syenogranite,which is consistent with the diagenetic-metallogenic age of Au-polymetallic deposits in Chaoyang-Chifeng area.