惠家沟地区金矿化地质特征及其成因探讨

惠家沟金矿化区位于南秦岭印支冒地槽褶皱带东南端公馆—回龙汞锑矿带边缘。矿体呈层状,似层状赋存于中泥盆统杨岭沟组中上部碎屑岩—碳酸盐岩建造的浅变质细碎屑岩中。受层位、有利岩性和顺层韧～脆性剪切破裂带控制。矿化与硅化、黄铁矿化、毒砂化关系密切。金主要呈超显微自然金包含于毒砂黄铁矿中。矿化区中除 Au 外,尚伴有 As、Sb、Hg 等元素,并形成 Au—As—Sb—Hg 组合异常。成矿物质主要来源于容矿地层。成矿热液属大气降水与变顾热水的混合热液。成矿温度偏低、压力小。在矿化地质特征上,经初步研究认为类似卡林型金矿。由于该矿床多属地表工程控制,所获样品结果品位偏低,矿石中砷含量较高,且经初步选矿试验,金回收率较低,因此,矿石是否能被工业利用,尚待进一步研究探讨。

THE GEOLOGICAL FEATURFS AND THE GENESIS OF THE GOLD MINERALIZATION IN THE HUIJIAGOU REGION

The gold mineralization region is located in the margin of the Gongguan- Huilong Hg-Sb ore belt in the southeast end of the Indosinian miogeosyncl- ine folding belts of the southern Qinling mountains.Controlled by strata, favourable lithozones and bedding ductile-brittle shear fractural zones,the orebodies with stratiform and layer-like occured in the epimetamorphosed detrital rock in the middle-upper part of the middle Devonian Yanglinggou Formation.The gold mineralization is closely associated with silication, pyritization and arsenopyritization.Gold minerals,included in arseno-pyrite ores,are mainly ultramicroscopic.In the mineralized region,there are other elements such as As,Sb,Hg etc.,forming a compositional anormaly of Au -As-Sb-Hg.The ore-forming materials were mainly deprived from the host strata.The hydrothermal ore-forming solution is a mixed solution of meteo- ric water and metamorphosed fluids.The ore-forming temperature was lower and the pressure was little.According to the geological and the mineraliz- ational features,the writer considered that the gold-mineralization in the Huijiagou region should be simillar to the Carlin-type gold deposit.