摘要
松湖铁矿床位于阿吾拉勒地区东部,矿体呈层状产在石炭系阿吾拉勒组火山岩-火山碎屑岩建造中。微量元素地球化学特征显示,松湖铁矿床赋矿围岩形成于岛弧构造环境。松湖铁矿床含有草莓黄铁矿、他形-半自形黄铁矿(含有大量黄铁矿化生物遗骸)和钴黄铁矿三种不同成因的黄铁矿。铁成矿前沉积成因草莓黄铁矿受成矿热液影响发生重结晶,其钴含量及Co/Ni比值明显增大。铁成矿期的他形-半自形黄铁矿和伴生的黄铁矿化生物遗骸具有相对较高的钴含量和Co/Ni比值,显示其成矿流体与火山活动有密切的成因联系,松湖铁矿床后期叠加了铜-钴矿化作用,形成了大量的黄铜矿和钴黄铁矿。钴黄铁矿的钴含量>1%,Co/Ni比值>26,显示该矿床铜、钴的富集过程与后期火山作用有关,该矿床是一个与火山岩有关的沉积型铁矿床,其形成温度为270～325℃。
The Songhu iron deposit is located in the eastern part of Awurale region, and its bed-like orebodies occurred in the voleanic-pyroclastic rocks of the Lower Carboniferous Awurale Formation. The volcanic rocks, as the wall/host rocks of the deposit, were formed in an island arc tectonic setting according to their trace element geochemistry. Three genetic types of pyrite have been distinguished in the deposit: the framboidal, the anhedral-subhedral ( with a large amount of pyritized bio-remains), and the cobalt pyrite. The pre-iron ore framboidal pyrite of sedimentary origin recrystallized due to the reworking of ore-forming hydrothermal solution, accompanied by the apparent increasing of its Co content and Co/Ni ratio. The iron ore-stage anhedral-subhedral pyrite and associated pyritized bio-remains possess relatively higher Co contents and Co/Ni ratios, indicating the close relationship between the ore-forming fluid and the magmatic (volcanic) activities. The Songhu iron deposit was superimposed by late stage Cu-Co mineralization, in which a large amount of chalcopyrite and cobalt pyrite were formed. The Co content of cobalt pyrite can be over 1% and its Co/Ni ratio over 26. It is suggested that the process of Cu-Co enrichment in the deposit is closely related to the latter stage of volcanic activity, This deposit could be recognized as a volcanic exhalative sedimentary iron deposit, and its ore-forming temperature ranges from 270 degrees C to 325 degrees C.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第6期1456-1464,共9页
Acta Petrologica Sinica
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-107)
"十一五"国家科技支撑计划(2006BAB07BO2-03)资助.
作者简介
单强,男,1967年生,副研究员,主要从事矿床地球化学研究,E-mail:qshan@gig.ac.cn
