Post-collisional porphyry Cu deposits are genetically related to the magmas generated by partial melting of sulfide-bearing lithosphere fertilized by subduction components. The ore-forming magmas are suggested to be enriched in chalcophile elements compared to the barren magmas. However, the chalcophile element contents in the post-collisional magmas and its role in controlling the porphyry ore formation remain unclear. Platinum-group element (PGE) geochemistry has been used as a proxy for Cu and Au. In this study, we report PGE concentrations of representative post-collisional ore-associated and barren suites in the eastern Tethyan metallogenic domain. The ore-associated suites have moderate Pd and Pt contents ranging from ~ 0.05 to 0.5 ppb, which are comparable to those associated with giant porphyry systems in continental arc settings. In contrast, most of the barren suites have systematically lower Pd and Pt concentrations below ~ 0.1 and 0.05 ppb, respectively. Numerical models show that the ore-forming magmas, derived from partial melting of subduction-modified lithospheric mantle, have precipitated a small amount of sulfide phases during magma differentiation, leading to the moderate depletion of Pd and Pt in the ore-associated suites. Although the sulfide segregation has depleted highly chalcophile element contents, the ore-forming magmas contain sufficient Cu to form porphyry Cu deposits. This contrasts with the barren suites, which mainly originated from partial melting of the lower crust and contain about five times lower Cu contents, unfavorable for porphyry Cu mineralization. We suggest that moderate chalcophile element contents in the ore-associated magmas have increased the porphyry ore-forming potential in the eastern Tethyan domain.

碰撞后斑岩铜矿床在成因上与俯冲成分孕育的含硫化物岩石圈部分熔融所产生的岩浆有关。与贫瘠岩浆相比，成矿岩浆富含亲铜元素。然而，碰撞后岩浆中亲铜元素的含量及其对斑岩矿形成的控制作用仍不清楚。铂族元素 (PGE) 地球化学已被用作铜和金的代表。在这项研究中，我们报告了特提斯成矿域东部典型的碰撞后成矿区和贫瘠区的 PGE 浓度。与矿石相关的套件具有中等的 Pd 和 Pt 含量，范围为 0.05 至 0.5 ppb，与大陆弧环境中的巨型斑岩系统相关的含量相当。相比之下，大多数贫瘠套房的 Pd 和 Pt 浓度分别低于 0.1 和 0.05 ppb。数值模型表明，俯冲改造岩石圈地幔部分熔融形成的成矿岩浆，在岩浆分异过程中析出少量硫化物相，导致伴矿岩层中Pd、Pt适度损耗。尽管硫化物偏析使亲铜元素含量较高，但成矿岩浆中含有足够的铜，可形成斑岩铜矿床。这与贫瘠岩套形成鲜明对比，贫瘠岩套主要源自下地壳的部分熔融，其铜含量低约五倍，不利于斑岩铜矿化。我们认为伴矿岩浆中的中等亲铜元素含量增加了特提斯东部域斑岩成矿潜力。