Reconstructing the Magmatic and Hydrothermal Evolution of the Au-rich, Cu-Poor Dorado Porphyry Deposit, Chile: Implications for Cu/Au Ratios in Porphyry Deposits Worldwide

重建智利富金、贫铜多拉多斑岩矿床的岩浆和热液演化：对全球斑岩矿床中铜/金比率的影响

• 批准号: 2214119
• 负责人: Adam Simon
• 金额: $ 35.76万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2214119&HistoricalAwards=false
• 关键词: Reconstructing; Magmatic; Hydrothermal; Evolution; Au

Globally, society consumes about 300 percent more copper and 100 percent more gold every year than in the year 1960. Production of copper and gold over the next several decades must increase significantly to achieve the United Nations Sustainable Development Goals of providing electricity to nearly one billion people on Earth for whom the lack of electricity contributes to economic impoverishment, as well as building renewable energy infrastructure to replace fossil fuels globally. To meet this demand at a scale and speed never before accomplished by humans, geologists must refine the models used to explore for and locate new copper and gold deposits. Currently, one mineral deposit type, referred to by geologists as a porphyry copper gold deposit, supplies the majority of the world's copper and about 15 percent of the world's gold. This project will investigate the formation of gold-rich porphyry deposits in the Maricunga belt of Chile, the world's leading producer of copper. These gold-rich porphyry deposits are poorly understood and finding new deposits requires a better understanding of the geologic processes that form them. The anticipated results will help constrain how the gold-rich deposits in Chile formed and allow geologists to improve their exploration strategies for new, undiscovered deposits. Porphyry-mineral deposits formed in subduction zone environments are society’s most important source of copper and an important source of gold. There is consensus for the general geologic model that explains the formation of porphyry mineral deposits. However, there is no consensus on why the ratio of metals such as copper to gold varies by several orders of magnitude among these deposits. Existing hypotheses to explain the variability of copper to gold ratios invoke: 1) the depth of emplacement of the upper crustal source magma and its impact on the evolution of the magmatic-hydrothermal ore fluid; 2) the composition of the source magma that represents a first order control on the partitioning of ore metals and their fluid-soluble ligands between melt and magmatic-hydrothermal ore fluid; 3) the redox conditions attending the evolution of magmatic systems that play a role in the relative mobility of copper vs. gold. The project outcomes will help clarify the evolution of the Dorado Au-porphyry system from magma emplacement to Au-rich, Cu-poor porphyry formation. This project has the potential to significantly change our understanding of the variability of copper to gold ratios in porphyry mineral systems and help guide exploration for Au-rich systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在全球范围内，与 1960 年相比，社会每年消耗的铜增加约 300%，黄金消耗增加约 100%。未来几十年铜和金的产量必须大幅增加，才能实现为近 10 亿人提供电力的联合国可持续发展目标地球上的人们因缺乏电力而陷入经济贫困，并在全球范围内建设可再生能源基础设施以取代化石燃料。为了以人类前所未有的规模和速度满足这一需求，地质学家必须完善模型。目前，一种被地质学家称为斑岩铜金矿床的矿床供应了世界上大部分的铜和约 15% 的金矿。该项目将进行勘探。世界领先的铜生产国智利马里昆加带富金斑岩矿床的形成人们对这些富金斑岩矿床知之甚少，寻找新的矿床需要更好地了解。预期的结果将有助于限制智利富金矿床的形成方式，并使地质学家能够改进在俯冲带环境中形成的新的、未发现的斑岩矿床的勘探策略，这些矿床是社会最重要的资源。铜和金的重要来源 对于解释斑岩矿床形成的一般地质模型存在共识，但对于铜等金属与金的比例为何相差几个数量级尚未达成共识。解释铜与金比例变化的现有假设涉及：1）上地壳源岩浆的侵位深度及其对岩浆-热液矿石流体演化的影响；源岩浆代表了对矿石金属及其可溶于流体的配体在熔体和岩浆-热液矿石流体之间分配的一级控制；3）参与岩浆系统演化的氧化还原条件该项目的成果将有助于阐明多拉多金斑岩系统从岩浆侵位到富金、贫铜斑岩形成的过程。该项目有可能显着改变我们的研究结果。了解斑岩矿物系统中铜与金比例的变化，并有助于指导富金系统的勘探。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Formation of oxidized sulfur-rich magmas in Neoarchaean subduction zones

• DOI: 10.1038/s41561-022-01071-5
• 发表时间: 2022-11
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Xuyang Meng;A. Simon;Jackie Kleinsasser;D. Mole;D. Kontak;P. Jugo;Jing-Qiao Mao;J. Richards

Formation of the Chah-Gaz iron oxide-apatite ore (IOA) deposit, Bafq District, Iran: Constraints from halogens, trace element concentrations, and Sr-Nd isotopes of fluorapatite

• DOI: 10.1016/j.oregeorev.2021.104599
• 发表时间: 2021-12
• 期刊: Ore Geology Reviews
• 影响因子: 3.3
• 作者: Fatemeh Sepidbar;G. Ghorbani;A. Simon;Jinlong Ma;R. Palin;Seyed Masoud Homam

Integrated O, Fe, and Ti isotopic analysis elucidates multiple metal and fluid sources for magnetite from the Ernest Henry Iron oxide copper gold (IOCG) Deposit, Queensland, Australia

• DOI: 10.1016/j.oregeorev.2022.105170
• 发表时间: 2022-11
• 期刊: Ore Geology Reviews
• 影响因子: 3.3
• 作者: Christopher R. Emproto;R. Mathur;A. Simon;I. Bindeman;L. Godfrey;C. Dhnaram;V. Lisitsin

Where did the Earth’s oxygen come from? New study hints at an unexpected source.

地球上的氧气从哪里来？

• 发表时间: 2022
• 期刊: The Conversation
• 作者: https://tinyurl.com/MoleSimonMeng