Collaborative Research on the Iceland Deep Drilling Project: An Investigation of a High-Temperature Mid-Ocean Ridge Hydrothermal System in a 5 km Deep Borehole

冰岛深层钻探项目（IDDP）将研究冰岛西南端雷克雅内斯半岛的高温（~ 450℃）热液流体与海洋地壳的相互作用，那里是大西洋中脊从海洋中出现的地方。由于钻探5公里深井的大部分成本将由工业界和冰岛政府承担，国际大陆科学钻探计划（International Continental Scientific drilling Program）将参与其中，因此所要求的资金将具有很高的杠杆作用。冰岛一家地热发电公司正在提供一个现有的约3公里深的井，以将深度加深到5公里。该项目将首次在全球范围内提供机会，研究大洋中脊热液系统的深层高温反应区，这一直是海洋钻探计划的长期目标。该钻探地点的理想位置是进行一系列涉及玄武岩和海水在高温下达到超临界条件下的反应的科学研究。在控制黑烟流体成分的深层、高温反应区内的这种活跃过程，以前从未有过全面的直接研究和采样。海洋钻探仅深入5亿年的海洋地壳2公里。温度为~ 180℃。相比之下，IDDP与冰岛工业界的合作将从3公里、4公里和5公里的流动测试中获得流体样本，从4.0公里深度的钻屑和现场岩心中获得流体样本，并从4.0至5.0公里深度的连续岩心中获得1.0公里的流体样本。这些样品将揭示400℃下玄武岩-海水相互作用的综合记录。对这些材料的研究将使我们对活跃热液过程的理解有一个巨大的飞跃，这在全球范围内是重要的。所提供的资金将用于：(1)为科学目的取芯；(2)支持井场的科学项目、流体取样、岩心处理和岩心的基本岩石学表征，并将子样本和数据分发给经批准的国际科学家名单；(3)支持美国Co-PI协调小组研究热液/岩石相互作用和地球化学模拟。将被回收的岩心和流体可能表征一个主要热液系统的下边界，从而为控制热液系统上限的因素提供重要证据。

0507625EldersThe Iceland Deep Drilling Project (IDDP) will study the interaction of high-temperature (~ 450oC) hydrothermal fluids with oceanic crust on the Reykjanes Peninsula, at the southwestern tip of Iceland, where the Mid-Atlantic Ridge emerges from the ocean. The requested funds would be highly leveraged because most of the cost of drilling a 5km deep borehole will be borne by industry and the Icelandic government, with participation from the International Continental Scientific Drilling Program. An Icelandic geothermal power company is providing an existing ~ 3 km deep well for deepening to 5 km depth. This project will provide the first opportunity worldwide to investigate the deep, high temperature reaction zone of a mid-ocean ridge hydrothermal system, which has been a long-standing goal of the Ocean Drilling Program. This drill site is ideally situated for a broad array of scientific studies involving reactions between basalt and seawater at high temperatures, reaching supercritical conditions. Such active processes in the deep, high temperature reaction zones that control fluid compositions of black smokers have never before been available for comprehensive direct study and sampling. Ocean drilling has penetrated only 2 km into 5 Ma old ocean crust. where temperatures were ~ 180 oC. In contrast, the IDDP collaboration with industry in Iceland will produce fluid samples from the flow tests at 3, 4, and 5 km, drill cuttings and spot cores down to 4.0 km depth, and 1.0 km of continuous drill core from 4.0 to 5.0 km depth. These samples will reveal the integrated record of basalt-seawater interactions at 400oC. The study of these materials will permit a quantum leap in our understanding of active hydrothermal processes that are important on a global scale, The funds provided will be used for: (1) coring for scientific purposes; (2) support for the scientific program at the well site, for fluid sampling, for core handling, and for basic petrologic characterization of the cores, and distribution of sub-samples and data to an approved list of international scientists; and (3) support for a coordinated group of US Co-PI's investigating hydrothermal water/rock interactions and geochemical modeling. The core and fluids that will be retrieved may characterize the lower boundary of a major hydrothermal system and thus provide important evidence about what controls the upper temperature limits of hydrothermal systems.