Continued Geochronologic, Paleomagnetic, and Rock-Magnetic Studies of the Parana-Etendeka Flood Volcanic Province

拟议的研究将为澄清非洲西南部和南美洲东部巴拉那-埃滕迪卡省（PEP）洪水火山活动的时空演变提供基础数据。 PEP是已知的最大的大陆洪水火山省之一，这里获得的数据将与洪水火山作用起源的更广泛的问题有关。 火山活动、特里斯坦-达库尼亚热点和南大西洋早白垩世裂谷之间的关系将通过高精度的地质年代学、古地磁学和岩石磁学工作来阐明，这些工作将与正在进行的地层学和岩石学研究相结合。 将为纳米比亚埃滕代卡省和乌拉圭巴拉那省的火山岩剖面建立新的详细的磁性地层学。 将推导出南美洲和南部非洲在年间隔内精确且日期明确的表观极移路径（APWP） 135-120 Ma; APWP将量化由于南大西洋不对称开放引起的旋转，并将用于改进特里斯坦热点的轨迹。 40 Ar/39 Ar和U/Pb测年将用于更确定地限制火山活动的任何迁移趋势。 跨大西洋的个体流动之间的相关性将进行测试古地磁和岩石磁性;这种相关性的必然结果将是一个高精度的基础上，西冈瓦纳大陆的漂移前重建。 火山流动方向的确定（源的约束位置）将尝试使用磁化率（AMS）的各向异性从广泛分离的流动序列，特别是单位正在测试跨大西洋的相关性。

9628065 Renne The proposed research will provide fundamental data toward clarifying the spatial-temporal evolution of flood volcanism in the Parana-Etendeka province (PEP) of southwestern Africa and eastern South America. The PEP is one of the largest continental flood volcanic provinces known, and data acquired herein will be relevant to broader questions about the origin of flood volcanism. Relations between volcanism, the Tristan da Cunha hotspot, and Early Cretaceous rifting of the South Atlantic will be elucidated by high-precision geochronologic and paleomagnetic and rock magnetic work that will be done in connection with ongoing stratigraphic and petrologic studies. New and detailed magnetostratigraphy will be established for volcanic sections in the Etendeka Province of Namibia as well as the Parana Province of Uruguay. Refined and well-dated apparent polar wander paths (APWP's) will be derived for both South America and southern Africa over the interval of 135-120 Ma; the APWP's will quantify rotation due to asymmetric opening of the South Atlantic and will be used to refine the trace of the Tristan hotspot. 40Ar/39Ar and U/Pb dating will be used to constrain with greater certainty any migratory trends in volcanism. Correlations between individual flows across the Atlantic will be tested paleomagnetically and rock-magnetically; a corollary of such correlation will be a high-precision basis for pre-drift reconstruction of western Gondwanaland. Determination of volcanic flow directions (constraining locations of sources) will be attempted using anisotropy of magnetic susceptibility (AMS) from widely separated flow sequences, particularly units being tested for Transatlantic correlation.