COLLABORATIVE RESEARCH: Chemical Fingerprinting of Ash Beds in the Terminal Proterozoic Nama Group of Namibia

合作研究：纳米比亚末元古代Nama群灰岩的化学指纹图谱纳米比亚末元古代至寒武纪Nama群是最全面的末元古代事件记录之一。Nama群的Schwarzrand亚群包含15个地层学上不同的火山灰层，根据U-Pb年代学的限制，这些事件层的时间跨度最多为6 m.这些事件层作为高分辨率、广泛分布、时间平行的层具有巨大的年代地层学价值。这项可行性研究将评估使用地球化学指纹技术来唯一识别和关联Schwarzrand suyb群中的灰层的潜力。根据物理性地层学已经很好地建立了一些广泛分布的灰层的相互关系。对来自这些地层的样品进行整体岩石和流体包裹体研究，将控制地层内化学特征的可变性。Schwarzrand亚群的三个完全分开的部分几乎保存了所有的灰层。对这些剖面的灰层样品进行综合分析，将比较床层和床内成分的差异，并将测试指纹识别方法的分辨率。

Collaborative research: Chemical Fingerprinting of Ash Beds in the Terminal Proterozoic Nama Group, NamibiaBeverly Saylor.0073700Warren Huff.0073834The terminal Proterozoic to Cambrian Nama Group of Namibia is one of the most comprehensive records of end Proterozoic events. The Schwarzrand Subgroup of the Nama Group contains 15 stratigraphically distinct volcanic ash beds, which are constrained by U-Pb geochronology to a time span of at most 6 m.y. These event beds have tremendous chronostratigraphic value as high-resolution, widespread, time-parallel layers. This feasibility study will evaluate the potential for using geochemical fingerprinting techniques to uniquely identify and correlate ash beds in the Schwarzrand Suybgroup. Correlations of some widespread ash beds are already well established based on the physical stratigraphy. Whole rock and fluid inclusion studies of samples from these beds will control for within bed variability of chemical signature. Three widely separated, complete sections of the Schwarzrand Subgroup preserve nearly all the ash beds in replicate. Comprehensive analyses of ash bed samples from these sections ill compare between bed vs. within bed compositional differences and will test the resolution of the fingerprinting method.