The Timing, Duration and Correlation of North Atlantic Igneous Province Magmatism

9903056邓肯我们将参加一项国际合作调查的时间，成因和北大西洋火成岩省（NAIP），一个典型的火山裂谷边缘的演变。有人提出，这一大火成岩省是在冰岛地幔柱活动开始时形成的，其残余包括西格陵兰和东格陵兰边缘玄武岩、法罗群岛、英属第三纪省以及形成北大西洋大部分大陆边缘的大量熔岩流和岩床（向海倾斜反射体）。我们将通过40 Ar-39 Ar增量加热法对整个岩石和矿物分离物进行放射性年龄测定，以确定火山活动的时间和持续时间，并支持全省火山地层学的相关性。 需要精确的年龄测定，以建立广泛分离的火山和侵入残余物的时间框架，通过火山历史确定岩浆生产率，描述不同构造背景下岩浆阶段的序列和持续时间，并将火山高峰期与这一大火成岩省的环境响应的沉积记录相关联。该计划的第一个目标是使用全省的岩浆活动和构造活动的记录，以评估在地幔柱存在的情况下大陆裂谷的“主动”（柱头）与“被动”（柱孵化）模型。

9903056DuncanWe will participate in an international collaborative investigation of the timing, genesis and evolution of the North Atlantic Igneous Province (NAIP), a classic volcanic rifted margin. It has been proposed that this large igneous province was constructed at the initiation of Iceland mantle plume activity, remnants of which include the West and East Greenland margin basalts, the Faeroe Islands, the British Tertiary Province, and extensive sequences of lava flows and sills that form most of the continental margins of the North Atlantic (seaward-dipping reflectors). We will contribute radiometric age determinations by the 40Ar-39Ar incremental heating method, for whole rock and mineral separates to define the timing and duration of volcanism, and in support of correlating volcanic stratigraphy across the province. Precise age determinations are required to establish the timeframe of widely separated volcanic and intrusive remnants, determine magma production rates through the volcanic history, describe the sequence and duration of magmatic phases in different tectonic settings, and correlate peak volcanic phases with the sedimentary record of environmental response to this large igneous province. The first order goal of the program is to use the record of magmatism and tectonism throughout the province to assess "active" (plume head) vs "passive" (plume incubation) models of continental rifting in the presence of a mantle plume.