"Metallogeny of arcs, from subduction-related to post-subduction processes"

“弧的成矿作用，从俯冲相关到俯冲后过程”

• 批准号: 203099-2012
• 负责人: Richards, Jeremy
• 金额: $ 2.33万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569859
• 关键词: Metallogeny; arcs; subduction; related; post

Magmatic arcs related to the subduction of oceanic lithosphere are prospective for porphyry Cu±Mo±Au and epithermal Au deposits. Recently, porphyry and epithermal deposits that formed after subduction ceased have also been recognized in several parts of the world; these deposits may be generated during or after collisional processes. This research program aims to examine the tectonic and magmatic controls on porphyry and epithermal ore deposit formation that operate both during and after subduction. The main questions to be addressed by this research program are: (1) How do magmas with ore-forming potential ("fertile" magmas) form in arc environments?; (2) Can any chemical or mineralogical indicators of magma fertility be identified?; (3) Can we learn anything about fertile magma formation by studying the exposed deep crustal roots of arc systems?; and (4) What does the occurrence of post-subduction porphyry and epithermal systems tell us about the way subduction processes affect the deep lithosphere? These questions will be addressed by targeted fieldwork, with special focus on the arc terranes of North and South America, and the Tethyan belt of Turkey-Iran-Pakistan-Tibet. Geochemical, isotopic, and geochronological analyses will be undertaken on collected samples to constrain the timing and evolution of fertile magmatic suites within their regional tectonomagmatic context, and to identify key parameters that control prospectivity. High pressure/temperature experimental work will also be undertaken to explore the behaviour of metals during melting of subduction-modified lithosphere. This research is expected to be of interest to the Canadian and international mineral exploration industries, and will also shed light on magmatic processes occurring in the deep lithosphere during and after subduction.

与大洋岩石圈俯冲作用有关的岩浆弧是寻找斑岩型Cu±Mo±Au和浅成低温热液型Au矿床的有利地段。最近，在世界一些地方也发现了俯冲停止后形成的斑岩和浅成热液矿床;这些矿床可能是在碰撞过程期间或之后生成的。本研究计划旨在研究构造和岩浆对俯冲过程中和俯冲后斑岩和浅成低温热液存款形成的控制作用。 本研究计划要解决的主要问题是：（1）具有成矿潜力的岩浆（“肥沃”岩浆）是如何在弧环境中形成的？(2)能识别出岩浆肥力的化学或矿物学指标吗？(3)我们能通过研究弧系暴露的深地壳根来了解肥沃岩浆的形成吗？俯冲后斑岩和浅成热液系统的出现告诉我们俯冲过程如何影响深部岩石圈？ 这些问题将通过有针对性的实地考察来解决，特别关注北美和南美的弧形隆起，以及土耳其-伊朗-巴基斯坦-西藏的特提斯带。将对收集的样品进行地球化学、同位素和地质年代学分析，以限制区域构造岩浆背景下肥沃岩浆岩套的时间和演变，并确定控制远景的关键参数。还将进行高压/高温实验工作，以探索金属在俯冲变形岩石圈熔化期间的行为。 预计这项研究将引起加拿大和国际矿产勘探行业的兴趣，并将揭示俯冲期间和之后岩石圈深部发生的岩浆过程。