Magma Flow Directions in Ferrar Intrusive Rocks using Anisotropy of Magnetic Susceptibility Methods

摘要该奖项支持对费拉尔侵入岩现有样品进行磁化率各向异性（AMS）测量的探索项目，以初步提供岩浆流动方向。AMS方法是为数不多的能够确定岩浆流动方向，从而约束岩浆侵位模型的技术之一。费拉尔省（4000公里长）与南非的卡鲁省一起，代表了与冈瓦纳火山分裂有关的最重要的洪水玄武岩省。人们提出了各种各样的模型，其中费拉尔岩浆被认为是来自南非地下的一个点源，杜菲克地块下的点源，或者来自多个点源。AMS方法提供了对这些模型的直接测试。在费拉尔省进行的AMS工作非常少，因此不确定费拉尔岩石是否会产生任何岩浆流信息。目前，从该省3000公里范围内收集的Ferrar样品（75个岩心）已经可用，并将在即将到来的现场季节收集更多样品，并提供给该项目。这些样本将在密歇根大学古地磁实验室进行分析。结果将证明该方法在费拉尔省岩石上的可行性，并可能为费拉尔羽流与多源就位模型提供初步约束。

9711722 Grunow Abstract This award supports an exploratory program to measure the anisotropy of magnetic susceptibility (AMS) on existing samples of the Ferrar intrusive rocks to provide preliminary magma flow directions. The AMS method represents one of the few techniques available capable of determining magma flow directions and hence, constrain magma emplacement models. The Ferrar province (4000km long), along with the Karoo province in South Africa, represents the most significant flood basalt province associated with Gondwana break-up. Various models have been proposed in which the Ferrar magmas are thought to have emanated from a point source beneath South Africa, beneath the Dufek massif, or from multiple point sources. The AMS method provides a direct test of these models. Very little AMS work has been done on the Ferrar province and so it is uncertain whether the Ferrar rocks will yield any magma dlow information. Ferrar samples (75 cores) from a 3000 km segment of this province are presently available and more will be collected in the upcoming field season and made available to this project. These samples will be analyzed at the University of Michigan paleomagnetism laboratory. Results will demonstrate the viability of the method on Ferrar province rocks and may also provide preliminary constraints on Ferrar plume versus multiple source emplacement models.