青海省柴达木南北缘岩浆熔离型镍矿的找矿——以夏日哈木镍矿为例  

The prospecting for magmatic liquation type nickel deposits on the southern and northern margin of Qaidam Basin,Qinghai Province: A case study of the Xiarihamu Ni-Cu sulfide deposit

作　　者：潘彤 

机构地区：[1]青海省地质矿产勘查开发局,西宁810001

出　　处：《中国地质》2015年第3期713-723,共11页Geology in China

基　　金：国土资源部公益性行业科研专项"东昆仑地区多金属成矿系列与找矿突破"(201211037)资助

摘　　要：夏日哈木铜镍矿是在东昆仑造山带首次被发现的岩浆熔离型矿床,该类型矿床是青海省铜镍矿勘查研究方向之一。笔者通过夏日哈木镍矿成矿特征研究认为:碰撞伸展环境是夏日哈木超大型镍-钴硫化物矿形成的基本条件,成岩成矿年龄集中于早泥盆世,岩体侵位于古元古代金水口白沙河组,参与后期混染成矿作用。对柴达木南北缘岩浆熔离型镍矿的成矿条件分析发现:泥盆纪热事件显示柴达木盆地南、北缘在该期均发生了碰撞伸展作用和成矿作用,镁铁质-超镁铁质岩均侵入古老地层,地层硫参与成矿作用;成矿镁铁质-超镁铁质岩体与物探磁异常,Ni、Co、Cu组合异常相对应。综合分析,柴达木南北缘岩浆熔离型镍矿的找矿潜力大,提出了今后柴达木南北缘岩浆熔离型镍矿勘查重点是柴达木南缘的昆中岩浆弧带、柴达木北缘高压变质岩带、欧龙布鲁克陆块。The Xiarihamu Cu- Ni sulfide deposit is a magmatic liquation type deposit discovered for the first time in East Kunlun orogenic belt. This kind of ore deposits is one of the research directions of prospecting for Cu- Ni deposits in Qinghai Province.Based on a study of the metallogenic characteristics of the Xiarihamu Cu- Ni sulfide deposit, the authors hold that the collisional extension environment constituted the basic condition for the formation of the Xiarihamu superlarge Cu- Ni sulfide deposit, the rock- forming and ore- forming processes took place exclusively in early Devonion, and the rock body was emplaced in Paleoproteerozoic Baishahe Formation of Linshuikou, with the addition of the later hybridization mineralization. Based on an analysis of the metallogenic conditions of the magmatic liquation type Ni deposits on the southern and northern margin of QaidamBasin, the authors have also found that the Devonian thermal event indicated that collisional extension occurred on both the southern margin and the northern margin in this period, the ore- forming mafic- ultramafic rocks on both margins intruded into old strata,stratigraphic sulfur took part in the ore-forming process, and the ore-forming mafic-ultramafic rock bodies are consistent with the geophysical magnetic anomalies as well as Ni, Co, Cu combinational anomalies. An integrated analysis shows that the prospecting potential for magmatic liquation type Ni deposits on the southern and northern margin of Qaidam Basin is great. It is also pointed out that the key prospecting targets in this region is the central kunlun magma arc belt on the southern margin of Qaidam Basin, the high-pressure metamorphic belt on the northern margin of Qaidam Basin, and the Olongbuluck landmass.

关 键 词：夏日哈木镍铜矿 柴达木南北缘 找矿方向 

分 类 号：P618.63[天文地球—矿床学]