Collaborative Research: Quantifying Rates of Neoproterozoic Global Change, Ethiopia

adam Maloof，普林斯顿大学，厄尔- 1323158nicholas Swanson-Hysell，加州大学伯克利分校，厄尔- 1325230摘要虽然新元古代早期的碳、锶同位素、磁地层学和古生物学记录是世界各地地层剖面对比的主要依据，但辐射定标是有限的。大多数碳酸盐岩台地都是在远离火山爆发的被动边缘发育的，火山爆发可能会向盆地输送富含锆石的火山灰。埃塞俄比亚北部的Tambien群是解决这一问题的理想选择，因为它是一个厚的含碳酸盐岩序列，沉积在靠近活火山作用的弧后盆地中。我们将开发埃塞俄比亚北部Tambien群的综合化学地层学、古地磁和U-Pb年代学数据，为冰川期前1亿年（~820-720 Ma）的地层对比提供新的主干。我们的首要目标是了解在冰川期开始时，地球化学和古地理边界条件是如何以及何时形成的，这些条件允许全球冰川作用。该基金由国际科学与工程部联合资助。

Collaborative Research: Quantifying Rates of Neoproterozoic Global Change, EthiopiaByAdam Maloof, Princeton University, EAR-1323158Nicholas Swanson-Hysell, Univ. California, Berkeley, EAR-1325230ABSTRACTWhile carbon and strontium isotope, magnetostratigraphic, and paleontological records exist for the early Neoproterozoic Era, and are the primary bases for correlation of stratigraphic sections around the world, radiometric calibration is limited. Most carbonate platforms well-suited for the development of chemostratigraphic data are developed on passive margins far from explosive volcanic activity that might deliver zircon-rich ash to the basin. The Tambien Group of northern Ethiopia is ideal for solving this problem because it is a thick carbonate-containing succession deposited in a back-arc basin proximal to active volcanism. We will develop integrated chemostratigraphic, paleomagnetic and U-Pb geochronological data from the Tambien Group of northern Ethiopia to provide a new backbone for stratigraphic correlation in the 100 million years preceding Cryogenian glaciation (~820-720 Ma). Our overarching goal is to understand how and when potentially unique geochemical and paleogeographic boundary conditions were developed that allowed for global glaciation at the onset of the Cryogenian Period. This grant was jointly supported by the International Science and Engineering Division.