西藏多龙矿集区铁格隆南超大型Cu(Au、Ag)矿床硫锡砷铜矿研究及其地质意义     

王艺云  唐菊兴  宋扬  杨超  林彬  高轲 《矿床地质》2018,37(6):1281-1295

铁格隆南矿床位于班公湖-怒江成矿带西段多龙矿集区,是青藏高原发现的首例具有典型高硫型浅成低温热液矿化特征的超大型Cu(Au、Ag)矿床。笔者通过对该矿床进行系统的矿相学研究,结合电子探针显微分析,首次在该矿床发现了硫锡砷铜矿,虽然其总量不多,但其与不同矿物组合特征可反演其形成时的物化条件,对矿床成因类型判别具有一定指示意义。该矿床中的硫锡砷铜矿多为粒径约10μm的不规则细粒,无内反射,均质性,与硫砷铜矿、砷黝铜矿等Cu-As-S体系矿物伴生产出时呈乳黄色-淡黄色,与斑铜矿、黄铁矿、蓝辉铜矿等CuFe-S体系矿物伴生产出时呈乳褐色-浅褐色。根据矿物之间的交代关系发现,硫锡砷铜矿形成于黄铁矿、斑铜矿、砷黝铜矿、硫砷铜矿之后,蓝辉铜矿、铜蓝之前。电子探针分析显示,硫锡砷铜矿的基本成分包括Cu、As、V、S、Sn、Sb,普遍含有少量Fe、Ge、Zn,部分样品中含少量W、Au、Ag,以S原子数为32为基础,计算得出其分子式为Cu_(23.71～26.92)V_(1.43～2.10)(As_(2.55～5.86),Sb_(0～0.63))_(3.15～5.95)(Sn_(0～2.6),Ge_(0～0.7))_(0.01～2.60)(Fe_(0～2.4),Zn_(0～0.24))_(0～2.4)S_(32),其中,存在Sb~(5+)?As~(5+)和Sn~(4+)?Ge~(4+)、(As,Sb)~(5+)+Cu~+?(Sn,Ge)~(4+)+(Fe,Zn,Cu)~(2+)以及V~(5+)?V~(4+)+Cu~+等复杂的元素耦合置换。结合矿石矿物组合及蚀变组合分析指出,酸性或略偏中性的、中低温高硫化态环境是促使硫锡砷铜矿生成的关键控制因素。  相似文献   

Germanium-bearing Colusite in Siliceous Black Ore from the Ezuri Kuroko Deposit, Hokuroku District, Japan     

Kosei Komuro  Yoshimichi Kajiwara 《Resource Geology》2004,54(4):447-452

Abstract. Germanium‐bearing colusite occurs with sphalerite, galena, tetrahedrite‐tennantite, chalcopyrite and pyrite in microdruses and veinlets in the siliceous black ore from the Ezuri Kuroko deposit in the Hokuroku district of Japan. X‐ray microdiffractometry of this mineral gives strongest lines at 1.60, 1.32 and 1.09 Å, which are consistent with the known powder diffraction data of colusite. On the basis of 32 S atoms per formula unit, electron microprobe analyses yield empirical chemical formulae of (Cu_{24 0}Fe_0.3Zn_1.0)_σ25.3V_1.9(A_s4.8Sb_0.2)_σ5.0Ge _1.3S₃₂ for Ge‐bearing colusite in close association with sphalerite, and (Cu_24.6Fe_0.9)_σ25.4V_1.8(A_s4.1 Sb_0.2)_σ4.3Ge_1.7S₃₂ for that coexisting with chalcopyrite, consistent with the ideal formula of Cu_24+xV₂(As, Sb)_6‐x(Sn, Ge)_xS₃₂ (x = 0 to 2) proposed by Spry et al. (1994) for this mineral species. The Ge‐bearing colusite mineralization is suggested to have occurred concurrently with consolidation of the siliceous black ore, possibly during hydrothermal modification in association with the igneous activity of the Ohtaki quartz diorite of the later Onnagawa stage. It is likely that biogenic siliceous ooze, a possible precursor of the siliceous black ore, may have served as an in situ source of Ge as well as other essential rare elements, leading to the formation of Ge‐bearing colusite during transformation or recrystallization of biogenic opal into a‐quartz.  相似文献