青海二道沟金矿床黄铁矿标型对矿床成因的指示

Indication of pyrite type to origin of Erdaogou gold deposit,Qinghai

为查明二道沟金矿床成因,对其主要载矿矿物黄铁矿进行了标型研究。研究结果显示黄铁矿热电导型为P型占主导地位的N-P混合型,成矿温度主要集中在150~350℃之间,在化学成分上主要表现为铁亏型,同时发育硫亏型黄铁矿,Co、Ni含量分别为8%~11%和2%~8%,Co/Ni比值1. 13~5. 50,Au/Ag比值6. 00~25. 67。地质-地球化学特征表明:二道沟金矿床为一个受接触带构造控制的与燕山期构造-岩浆作用有关的岩浆期后热液矿床,构造与岩浆作用复合控矿特征明显。

In order to ascertain the genesis of Erdaogou gold deposit,the typomorphic study of pyrite,the main ore-bearing mineral,was carried out. The results show that pyrite thermal conductivity type is P-type dominated N-P mixed type. The metallogenic temperature mainly concentrates in the range of 150-350 ℃ . The main chemical composition of pyrite is iron deficiency type. At the same time,pyrite with sulfur deficiency type is developed. The content of Co and Ni are 8%-11% and 2%-8%,respectively. The ratio of Co/Ni is 1. 13-5. 50,Au/Ag ratio ranged from 6. 00 to 25. 67. Geological and geochemical characteristics show that Erdaogou gold deposit is a post-magmatic hydrothermal deposit controlled by contact zone structure and related to Yanshanian tectono-magmatism,and its ore-controlling characteristics are obvious.