Offset Drilling on the Southeast Greenland Volcanic Rifted Margin: UCDavis Participation on the 1998 DLC Drilling Cruise

推荐的项目包括资助加州大学戴维斯分校的两名研究人员参加丹麦岩石圈中心（DLC）在格陵兰岛东南部火山裂谷边缘的钻探巡航，计划于1998年8月20日进行，并对火山岩岩心进行为期三年的后续岩石学研究。此次巡航的主要钻探目标是在北纬63度和北纬66度之间的向海倾斜反射层（SDRS）的羽状边缘，以及北纬68度的格陵兰-冰岛隆起处，恢复基底岩性（第三纪熔岩、沉积物和大陆基底）。这些地点的岩心将用于实现三个主要研究目标：1)更全面地表征最早的岩浆产物和与大陆分裂相关的构造演化；2)填补我们对远离祖先冰岛地幔柱轴线的格陵兰东南边缘地幔源的理解上的关键空白（在ODP第152和163页的主题上进行扩展）；3)整合了东格陵兰洪水玄武岩序列、由东格陵兰-冰岛隆起组成的近海SDRS和冰岛西部火山序列的火山记录。加州大学戴维斯分校的参与者在为期40天的巡游期间和巡游后3年的科学研究期间将获得工资支持。将制作一份用于一般分发的巡航后报告，其中包含完整的核心描述，现场报告和初步结果（以ODP初始报告为模型）。后续的分析工作和综合工作将由加州大学戴维斯分校的PI小组、DLC（为钻井船租赁提供资金）和俄勒冈州立大学R. Duncan小组（40Ar/39Ar年龄测定）共同努力，建立与ODP第152和163号项目以及东格陵兰洪水玄武岩省陆上工作相关的合作科学项目。加州大学戴维斯分校的研究小组将对岩心材料进行岩石学和电子探针研究，并将通过电感耦合等离子体质谱法对整个岩石进行微量元素分析。主要元素分析（XRF）和放射性成因同位素研究（Sr-Nd-Pb-Os）将在哥本哈根地球科学中心进行。即将到来的钻探项目将是ODP第152和163分部钻探调查的直接延伸，预计将对裂谷边缘演化、岩石圈相互作用以及大陆-海洋过渡的本质做出根本性的贡献。采出的岩心和相关的科学发现对于编写供ODP-IODP审议的未来北大西洋深水钻探建议也将是高度相关和至关重要的。＊＊＊

OCE 98-11453 Lesher The recommended project involves funds for two researchers from the University of California, Davis to take part in the Danish Lithosphere Centre (DLC) drilling cruise to the Southeast Greenland volcanic rifted margin, scheduled for August 20, 1998, and for three years of follow-up petrologic studies on the volcanic rocks cored. The primary drilling objectives of the cruise are the recovery of basement lithologies (Tertiary lavas, sediments, and continental basement) along the feather-edge of the seaward-dipping reflector sequences (SDRS) between latitudes 63 degrees north and 66 degrees north, and on the Greenland-Iceland Rise at latitude 68 degrees north. Drill core from these sites will be used to achieve three primary research goals: 1) to more fully characterize the earliest magmatic products and the tectonic evolution associated with continental breakup; 2) to close critical gaps in our understanding of mantle sources along the southeast Greenland margin away from the axis of the ancestral Iceland mantle plume (expanding on a primary theme of ODP Legs 152 and 163); and 3) to unite the volcanic records for the East Greenland flood basalt succession, the offshore SDRS comprising the East Greenland-Iceland Rise, and the volcanic succession of western Iceland. Salary support is being recommended for the UC Davis participants during the 40 day cruise and for 3 years of post-cruise science. A post-cruise report for general distribution will be produced, containing a complete core description, site reports, and preliminary results (modeled after the ODP Initial Reports). Follow-up analytical work and the synthesis will be a collaborative effort between the PI's group at UC Davis, the DLC (funding the drill ship charter) and R. Duncan's group at Oregon State University (40Ar/39Ar age determinations), building on cooperative science programs related to ODP Legs 152 and 163 and onshore work in the East Greenland flood basalt province. The UC Davis group will conduct petrog raphic and electron microprobe studies of the core material, and will perform whole rock trace element analyses by inductively-coupled plasma mass spectrometry. Major element analyses (by XRF) and radiogenic isotope studies (Sr-Nd-Pb-Os) will be undertaken at the Copenhagen Geoscience Center. This upcoming drilling program will be a direct extension of drilling investigations by ODP Legs 152 and 163, and is expected to contribute fundamentally to the understanding of rifted margin evolution, plume-lithosphere interactions, and the nature of continent-ocean transition. The core recovered and associated scientific discoveries also will be highly germane and crucial to the preparation of future proposals for deep water drilling in the North Atlantic Ocean for consideration by ODP-IODP. ***