COLLABORATIVE RESEARCH: Revised Stratigraphy: Geochemical Fingerprinting, Paleomagnetism and 40Ar/39Ar Dating, Olduvai Gorge, Tanzania

9905383 SwisherOlduvai峡谷切割坦桑尼亚北方的塞伦盖蒂平原，露出一个25米长的窗口，进入东非上新世-更新世大陆记录。 暴露的连续200万年的古环境历史包含了广泛的脊椎动物记录（包括原始人）和丰富的文化记录，在人类进化的研究中具有重要意义。在最近的工作中发现的重要的相关性问题，在峡谷可以解决通过使用现场地层测量结合地球化学的凝灰岩的“指纹”约束放射性和古地磁测年。从理论上讲，一次火山爆发的产物具有独特的化学特征，并提供了同位素标记。每个凝灰岩可以使用矿物学，主要，次要和微量元素丰度数据的个别玻璃碎片，然后40 Ar/39 Ar使用富钾的个别长石晶体的“地球化学指纹”。古地磁记录将为我们的相关性提供独立的验证。合并后的数据集将为解释当地记录和与全球环境、古人类学和古地磁记录相关联提供关键的年代框架。

9905383SwisherOlduvai Gorge incises the Serengeti Plain of northern Tanzania and exposes a 25 kilometer-long window into the Plio-Pleistocene continental record of east Africa. The exposed continuous two million year paleoenvironmental history contains an extensive vertebrate record (including hominids) and a rich cultural record of central importance in the study of human evolution. Important correlation problems discovered during recent work in the Gorge can be resolved by using field stratigraphic measurements combined with geochemical "fingerprinting" of tuffs to constrain radiometric and paleomagnetic dating. The product of a single volcanic eruption, in theory, has unique chemical characteristics and provides an isochronous marker. Each tuff can be "geochemically fingerprinted" using mineralogy, and major, minor, and trace element abundances data for individual glass shards and then 40Ar/39Ar dated using potassium-rich individual feldspar crystals. The paleomagnetic record will provide an independent verification of our correlations. The combined data set will provide the crucial chronological framework for interpreting the local record and correlating with global environmental, paleoanthropolgical and paleomagnetic records.