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

冰岛深部钻探项目(IDDP)将研究高温(~450oC)热液与位于冰岛西南端的雷克扬斯半岛洋壳的相互作用，中大西洋海脊就是在那里浮出海洋的。所要求的资金将被高度杠杆化，因为钻探5公里深的井眼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 Science Drill Program)将参与其中。冰岛一家地热发电公司正在提供一口现有的约3公里深的井，以供加深到5公里深。该项目将在世界范围内提供第一次机会，调查大洋中脊热液系统的深部高温反应区，这一直是大洋钻探计划的长期目标。这个钻探地点是进行一系列科学研究的理想地点，这些科学研究涉及玄武岩和海水在高温下发生反应，达到超临界条件。在控制黑人吸烟者的流体成分的深层高温反应区中，这种活跃的过程以前从未被用于全面的直接研究和采样。大洋钻探仅在5 Ma古老的洋壳中穿透了2公里。那里的温度是~180摄氏度。相比之下，IDDP与冰岛工业界的合作将从3、4和5公里的流动测试中产生流体样本，钻屑和现场岩芯深度达到4.0公里，以及从4.0公里到5.0公里深度的1.0公里连续钻芯。这些样品将揭示400oC玄武岩-海水相互作用的完整记录。对这些材料的研究将使我们对全球范围内重要的活动性热液过程的理解有一个巨大的飞跃，所提供的资金将用于：(1)出于科学目的进行取心；(2)支持井场的科学计划、流体采样、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；以及(3)支持美国热水/岩石相互作用和地球化学模型研究的协调小组。将被取回的岩心和流体可能表征主要热液系统的下界，从而为控制热液系统温度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.