A genetic linkage between subduction- and collision-related porphyry Cu deposits in continental collision zones
A genetic linkage between subduction- and collision-related porphyry Cu deposits in continental collision zones
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DOI：
10.1130/g36362.1
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发表时间：
2015-03-01
期刊：
影响因子：
5.8
通讯作者：
Duan, Lianfeng
中科院分区：
文献类型：
--
作者：
Hou, Zengqian;Yang, Zhiming;Duan, Lianfeng
与大陆碰撞有关的斑岩铜矿床（PCD）的成因仍然存在争议。最常见的假设将它们的起源与源自俯冲改变的弧岩石圈的岩浆联系起来。然而，目前尚不清楚碰撞相关和俯冲相关的 PCD 之间是否存在遗传联系。在这里，我们研究了西藏南部侏罗纪俯冲相关的铜-金矿床和中新世碰撞相关的铜-钼斑岩矿床。侏罗纪 PCD 仅出现在侏罗纪弧的西段，该区域已耗尽类地幔同位素成分 [例如，(Sr-87/Sr-86)(i) = 0.7041-0.7048； epsilon(Nd(t)) 高达 7.5，epsilon(Hf(t)) 高达 18]。相比之下，在东部弧段没有发现侏罗纪 PCD，该弧段的同位素较少[例如，(Sr-87/Sr-86)(i) = 0.7041-0.7063、epsilon(Nd(t)) < 4.5 和 epsilon(Hf(t))
The genesis of continental collision-related porphyry Cu deposits (PCDs) remains controversial. The most common hypothesis links their genesis with magmas derived from subduction-modified arc lithosphere. However, it is unclear whether a genetic linkage exists between collision-and subduction-related PCDs. Here, we studied Jurassic subduction-related Cu-Au and Miocene collision-related Cu-Mo porphyry deposits in south Tibet. The Jurassic PCDs occur only in the western segment of the Jurassic arc, which has depleted mantle-like isotopic compositions [e.g., (Sr-87/Sr-86)(i) = 0.7041-0.7048; epsilon(Nd(t)) as high as 7.5, and epsilon(Hf(t)) as high as 18]. By contrast, no Jurassic PCDs have been found in the eastern arc segment, which is isotopically less juvenile [e.g., (Sr-87/Sr-86)(i) = 0.7041-0.7063, epsilon(Nd(t)) < 4.5, and epsilon(Hf(t))