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

我们将参与一项关于北大西洋火成岩省(NAIP)的时间、成因和演化的国际合作调查，这是一个典型的火山裂谷边缘。有人提出，这个大型火成岩省是在冰岛地幔热柱活动开始时建造的，残留物包括格陵兰西部和东部边缘玄武岩、法罗群岛、英国第三纪省，以及形成北大西洋大部分大陆边缘的广泛的熔岩流和岩床序列(向海倾斜的反射体)。我们将通过40Ar-39Ar增量加热法对全岩和矿物分离进行放射性年龄测定，以确定火山活动的时间和持续时间，并支持全省的火山地层学对比。需要精确的年龄测定来建立广泛分离的火山和侵入残留物的时间框架，通过火山史确定岩浆产率，描述不同构造环境中岩浆阶段的序列和持续时间，并将峰值火山阶段与这个大型火成岩省的环境响应的沉积记录相关联。该计划的首要目标是利用全省岩浆活动和构造活动的记录，评估在存在地幔热柱的情况下大陆裂谷的“主动”(热柱头部)和“被动”(热柱孕育)模式。

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.