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

9905383斯威舍·奥杜瓦伊峡谷切割了坦桑尼亚北部的塞伦盖蒂平原，展示了一扇25公里长的窗户，可以看到东非的上更新世大陆记录。公开的连续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，在人类进化研究中具有核心重要性。在峡谷最近的工作中发现的重要的对比问题可以通过使用现场地层学测量结合凝灰岩的地球化学“指纹”来限制放射性和古地磁测年来解决。从理论上讲，一次火山喷发的产物具有独特的化学特征，并提供了一个同步标志。每个凝灰岩都可以用矿物学和单个玻璃碎片的主要、次要和微量元素丰度数据进行“地球化学指纹”，然后用富含钾的单个长石晶体测定40Ar/39Ar的年龄。古地磁记录将为我们的相互关系提供独立的验证。合并后的数据集将为解释当地记录并与全球环境、古人类学和古地磁记录相关联提供关键的年代学框架。

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.