Site Surveys für IODP-Bohrungen im subtropischen Nordatlantik (Koordination der MARIA S. MERIAN Reise 11)

北大西洋副热带 IODP 钻探现场勘察（MARIA S. MERIAN 11 次行程的协调）

• 批准号: 115732296
• 负责人: Dr. Torsten Bickert
• 金额: --
• 依托单位: Zentrum für Marine Umweltwissenschaften (MARUM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/115732296?language=en
• 关键词: Site; Surveys; IODP; Bohrungen; im

MARIA S. MERIAN Cruise MSM 11 comprises two legs to the subtropical North Atlantic. Aim of the first leg is to investigate the North Pond sedimentary basin at the western flank of the Mid Atlantic Ridge at 23'N. Main objectives of the second leg are the seismic survey and sediment geology investigations ofthe continental slope off NW Afnca. Both legs are dedicated to the preparation of lODP drilling expeditions. North Pond, an isolated sediment pond located on the Western flank ofthe mid-Atlantic Ridge, offers the opportunity to study microbial communities and their activities in deeply-buried sediments and the underlying basement. One important argument for choosing North Pond is that the geochemistry, hydrology, and geologic setting of North Pond have been previously studied by a series of DSDP and ODP dnil holes and seafloor observatories. However the existing site survey data are not sufficient for the approved North Pond lODP drilling expedition, scheduled to take place not before FY 2010. The goal ofthe proposed investigations on MSM 11/1 is therefore to map North pond in a detailed way in order to be able to position planned lODP holes precisely. These surveys compromise a detailed seismic mapping of the sediment-basement interface of North Pond, additional heat flow data and geochemical and microbial sampling of the sediments. In addition dredging of the upper crust, surrounding North Pond, will help to better define the petrological setting of North Pond. The proposed MERIAN cruise together with the planned lODP drilling project will provide a unique comprehensive geophysical, (bio)geochemical and microbial data set for the study of the deep biosphere. Main topic of the proposed MSM 11/2 is the preparation of an lODP expedition entitled Neogene Paleoclimate and sediment transport at the continental margin of NW Africa. Between Cap Bojador, southeast of the Canary Islands, and the deltas of rivers Senegal and Gambia we intend to collect seismic data in five different areas as presite survey. 4 out of 10 sites should cover at least the last 10 to 15 Ma to reconstruct the Neogene development of the Afncan monsoon and to document the early Pliocene aridification of the north African continent. Further 6 sites should explore sediments in high accumulation areas for a high resolution study of rapid climate changes in the subtropics and related sediment transport. Another topic of the proposed cruise will be the investigation of particle transport and charactenstics off Cap Blanc. Longterm moorings of sediment traps, oceanographic and optical sensors at stations CB (since 1988) and CBi (since 2002) will be renewed. Additional samples of particles in the water column and at the sediment surface wil! be taken by water samplers, in-situ pumps, and multicorers.

MARIA S. MERIAN Cruise MSM 11 包括两条前往亚热带北大西洋的航线。第一段的目的是调查北纬 23 英尺大西洋中脊西侧的北池沉积盆地。第二阶段的主要目标是对西北非洲大陆斜坡进行地震调查和沉积物地质调查。两条线路都致力于为lODP 钻探探险做准备。北池是一个位于大西洋中脊西侧的孤立沉积池，为研究深埋沉积物和底层基底中的微生物群落及其活动提供了机会。选择北池的一个重要论据是，北池的地球化学、水文和地质环境先前已通过一系列 DSDP 和 ODP 钻孔和海底观测站进行了研究。然而，现有的现场调查数据不足以支持计划在 2010 财年之前进行的北池塘 lODP 钻探考察。因此，拟议的 MSM 11/1 调查的目标是详细绘制北池塘地图，以便能够精确定位计划的 lODP 钻孔。这些调查包括北池沉积物-基底界面的详细地震测绘、额外的热流数据以及沉积物的地球化学和微生物采样。此外，对北池周围的上地壳进行疏浚，将有助于更好地确定北池的岩石学背景。拟议的 MERIAN 巡航以及计划中的 lODP 钻探项目将为深层生物圈的研究提供独特的综合地球物理、（生物）地球化学和微生物数据集。拟议的 MSM 11/2 的主要议题是准备题为“新近纪古气候和西北非洲大陆边缘沉积物迁移”的 lODP 考察。在加那利群岛东南部的博哈多尔角以及塞内加尔和冈比亚河流三角洲之间，我们打算收集五个不同地区的地震数据作为现场勘察。十分之四的地点应至少覆盖过去 10 至 15 Ma，以重建非洲季风的新近纪发展并记录北非大陆上新世早期的干旱化。另外 6 个地点应探索高积累区的沉积物，以便对亚热带快速气候变化和相关沉积物迁移进行高分辨率研究。拟议巡航的另一个主题将是调查勃朗角附近的粒子传输和特征。 CB（自 1988 年起）和 CBi（自 2002 年起）站的沉积物收集器、海洋学和光学传感器的长期系泊装置将得到更新。水柱和沉积物表面的额外颗粒样本将会！由水采样器、现场泵和多核仪采集。