河南周庵铂族-铜镍矿床的地质特征及成因分析

GEOLOGY AND GENESIS OF THE ZHOU′AN PGE-CU-NI DEPOSIT,HENAN PROVINCE

周庵矿床产于杨子板块与中朝板块的缝合带内,即南秦岭造山带之苏家河前寒武纪地体的北缘,是伏于南阳盆地之下的大型隐伏铂族-铜镍硫化物矿床。含矿超基性杂岩侵位于中新元古界变质地层,蚀变强烈;铂族-铜镍矿体呈似层状产在超基性岩体之内接触带的强蚀变壳内,并主要位于岩体顶部和底部,属岩浆期后热液作用形成。该矿床是东秦岭发现的首例大型铂族-铜镍矿床,预示着秦岭地区同类矿床的找矿前景。

The Zhou＇an deposit,containing 0. 335× 10^6 t Ni,0. 180 6× 10^6 t Cu and 33.03 t Pt＋ Pd,is a large blind PGE-Cu-Ni deposit beneath the Nanyang basin. It is located at the suturing zone between the Yangtze and Sinokorea plates ,i. e. the northern margin the Sujiahe Precambrian terrane of the southern Qinling Orogen. The ore-bearing ultramafic complex intruded into the Meso-Neoproterozoic metamorphic strata and was strongly altered. The stratiform-like PGE-Cu-Ni orebodies are hosted in the strongly altered shell surround the inner contact zone of the ultramarie intrusion. They mainly occur on the top or at the bottom of the intrusion. All these characters suggest that the ores were formed by post-magmatism hydrothermal alteration. The most important is that the Zhou＇an deposit is the fist case of large-size PGE-Cu-Ni deposit discovered in the Qinling Orogen,which implies that the Qinling Orogen is potential for ore deposits of similar types.