Metallogeny of modern and ancient oceans

海底火山中金属沉积温泉的发现，特别是与化学合成生命的联系，是20世纪最引人注目的科学进步之一。世界上80%的活火山发生在海洋中，火山和热液活动现在被认为在海洋环境的硫、碳和金属循环中具有关键作用。然而，关于海底热液系统的多样性、来自不同来源的金属的流量以及从热液喷口向海洋装载金属的历史，仍然存在一些重要问题。海底火山活动在地球古代海洋中更为普遍，与之相关的热液活动是世界上许多最大和最有价值的矿藏的来源。然而，控制这些资源分布的潜在地球动力学因素还没有完全了解。为了解决其中一些问题，我们正在参与一项国际努力，以探索和记录海洋中各种不同火山和构造环境中的热液活动。这项研究的具体目标是：(1)确定现代海底热液系统中金属的不同来源、汇和运移路径；(2)对不同热液来源进入海洋的金属自然负载量进行量化，包括那些可能对远场环境有长期影响的金属；(3)将目前的金属通量与过去海底金属堆积的地质记录进行比较；(4)改进现代和古代火山地体的金属库存模型。这些目标将通过海底测绘和取样计划、相关实验室研究和关于古代矿藏的实地工作来实现。这项研究的数据将有助于建立地球海洋地球化学演化的新模型，并将在陆地矿产资源勘探中直接实际应用。

The discovery of metal-depositing hot springs at volcanoes on the seafloor, and especially the link to chemosynthetic life, was one of the most compelling scientific advances of the 20th century. 80% of the world's active volcanoes occur in the oceans, and the volcanic and hydrothermal activity is now recognized as having a critical role in the sulfur, carbon and metal cycles of the marine environment. However, important questions remain about the diversity of seafloor hydrothermal systems, the flux of metals from different sources, and the history of metal loading to oceans from hydrothermal vents. Seafloor volcanism was even more prevalent in Earth's ancient oceans, and the associated hydrothermal activity was responsible for many of the world's largest and most valuable mineral deposits. However, the underlying geodynamic factors controlling the distribution of these resources are not fully understood. To address some of these questions, we are participating in an international effort to explore and document hydrothermal activity in a variety of different volcanic and tectonic settings in the oceans. The specific objectives of the research are: (i) to identify different sources, sinks and transport pathways for metals in modern seafloor hydrothermal systems, (ii) to quantify the natural loading of metals to the oceans from different hydrothermal sources, including those metals with potentially lasting far-field environmental significance, (iii) to compare present-day fluxes of metals with the geological record of past metal accumulations on the seafloor, and (iv) to improve models of the metal inventory of both modern and ancient volcanic terranes. These objectives will be achieved through a program of seafloor mapping and sampling, related laboratory studies, and field work on ancient ore deposits. Data from this research will contribute to new models of the geochemical evolution of Earth's oceans and will have direct practical application in the exploration for land-based mineral resources.