海南石碌铁钴铜( 金) 矿床与 国内外IOCG 型矿床的对比研究

摘 要] IOCG 矿床是近些年来被认知的一种重要矿床类型,因其巨大的经济和理论研究价值受到 国内外矿业界和学术界的重视。海南石碌铁钴铜(金)矿床在构造环境、与岩浆岩的关系、矿体特征、元 素和矿物组合、围岩蚀变等方面与国外典型的IOCG 矿床有相似之处。该矿床处于大陆边缘拉张的裂 谷环境,早期火山沉积岩为成矿提供初始矿源,后期侵入岩对成矿具有重要的改造富集作用,矿体基本 呈层状、似层状及少量脉状产于石碌群第六层中,一般铁矿体在上,钴铜矿体在下,具Fe-Cu-Co( -Au) 多元素组合,铁氧化物主要为赤铁矿,蚀变以透辉石化、透闪石化为主;在成矿时代方面区别于多数产在 元古宙的IOCG 矿床,而是经历了新元古代海相火山喷流沉积阶段、加里东期区域变质阶段、海西-印支 期热液改造阶段和燕山晚期热液改造阶段。文章认为石碌铁钴铜(金)矿床不仅与IOCG 矿床有较多相 似之处,与国内内蒙古白云鄂博铁稀土铌矿床、四川拉拉铜铁金钴钼稀土矿床、新疆乔夏哈拉铁铜金矿 床、云南迤纳厂铁铜稀土矿床和东川稀矿山铁铜矿床等也有相似之处。因此,在中国开展寻找IOCG 矿 床尤其是大型矿床,是很有前景的。

Comparisons Between the Shilu Fe-Co-Cu(-Au) Deposit in Hainan Province and Other IOCG-Type Deposits at Home and Abroad

Abstract:The IOCG(Iron-oxide-copper-gold)-type deposit is an important deposit type known in recent years. It attracts much attention of scientists at home and abroad due to its great economic and scientific values. The Shilu Fe-Co-Cu (-Au) deposit is, to some extent, similar to typical IOCG deposits abroad in tectonic settings, magmatic rocks associated with the deposits, features of the ore bodies, element and mineral associations and alteration of country rocks. The Shilu deposit is located in an extensional rift setting of a continental margin. The early volcanic rocks provided the initial source, and the late intrusive rocks played an important role in the transformation and concentration of the deposit. Ore bodies occur in the layered, layer -like and a small amount of veins in the sixth layer of the Shilu Group. In general, iron ore bodies lie in the upper part and cobalt-copper ore bodies are in the lower. It has a multiple element associations of Fe-Co-Cu (-Au). Tremolitization and diopsidization are the dominant alteration in the district. In the metallogenic epoch, different from most IOCG deposits occurring in the Proterozoic, the Shilu deposit experienced submarine volcano exhalation stage in the Neoproterozoic, regional metamorphic stage in the Caledonian, hydrothermal transformation stage of the Hercynian-Indosinian period and hydrothermal transformation stage of the late Yanshanian period. Comparison shows that this deposit is similar to IOCG deposits in the rest world as well as some other deposits in China, such as the Baiyun Obo Fe-REE-Nb deposit in Inner Mongolia, Qiaoxiahala Fe-Cu-Au deposit in Xinjiang, Lala Fe-Cu-Au-Co-Mo-REE deposit in Sichuan Province, and Yinachang Fe-Cu-REE deposit and Xikuangshan Fe-Cu deposit in Yunnan Province. So it is promising to explore more IOCG deposits in China, especially those of large scales.