西藏驱龙铜矿单向固结结构石英中硫化物包裹体的发现：对矿床成因的约束

We used to believed that the metals and S of the porphyry copper deposit enriched during the magma-hydrothermal transition process, but recent studies have found that the magma process which before the fluid saturated may play a significant role in the metals and S enrichment, but there are little limits about the way and efficiency of enrichment. Unidirectional solidification texture（UST） is a superexcellence supporter to chase the metal and sulfur migrating, because it formed during the magma-hydrothermal transformation stage. Recently, abundant sulfide inclusions were found in UST host by mineralization -related intrusion of the Qulong porphyry deposit in Tibet by our pilot study. UST is usually thought to form during magma-hydrothermal transition, therefore, the existence of sulfide inclusions in UST may represent the sulfur saturation during the magma stage, and this may be the key process of the giant porphyry copper deposit forming. To check this hypothesis, we plan to investigate the sulfide inclusions and related fluid/melt incusions, hydrothermal sulfide in veins and magmatic sulfide in MME using recently-emerged in situ analysis techniques (e.g., LA-(MC)-ICP-MS, SHRIMP): (1) the characteristics of sulfide inclusions (distribution, trace elements, S and Pb isotope) (2) the relationship between sulfide inclusions and fluid/melt inclusions and the characteristics (composition, formation temperature, Cu contents and so on); (3) the characteristics of magmatic sulfide and hydrothermal sulfide (trace elements, S isotope) ; (4) clarify the genesis of sulfide inclusions and figure out how much contribution of the sulfide saturation to the formation of Qulong giant porphyry copper deposit.

过去通常认为形成斑岩铜矿所需的金属和S，主要通过岩浆-热液过渡过程富集,但最近研究发现，流体饱和前的岩浆过程也可能对金属和S的富集起到重要作用，但该过程中金属和S富集的方式、效率等问题并未得到较好限制。单向固结结构是产于岩浆-热液过渡过程的一种特殊结构，是探究岩浆-热液转换过程中金属和S等成矿物质如何迁移及分配的绝佳载体，本研究拟以驱龙斑岩铜矿单向固结结构中发现的硫化物包裹体为研究对象，在详细的岩相学、特别是阴极发光岩相学基础之上，采用激光消融等离子质谱、离子探针等原位分析技术，开展单向固结结构石英中硫化物包裹体的微量元素及S，Pb同位素地球化学研究，并与驱龙矿床暗色包体中的岩浆硫化物与热液脉中硫化物微量元素及S，Pb同位素特征进行对比，结合单向固结结构中熔体/流体包裹体的温度压力及组分特征，揭示硫化物饱和在形成超大型斑岩矿床中的作用，重塑驱龙斑岩矿床的成矿过程，揭示矿床成因。