International Research Fellowship Program: The Break-up of the Rodinia Supercontinent and Snowball Earth: Paleogeography and Geochronology of the Western Amazon Craton

国际研究奖学金计划：罗迪尼亚超大陆和雪球地球的分裂：亚马逊克拉通西部的古地理和地质年代学

• 批准号: 0301807
• 负责人: Eric Tohver
• 金额: $ 9.54万
• 依托单位: Tohver Eric
• 依托单位国家: 美国
• 项目类别: Fellowship
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0301807&HistoricalAwards=false
• 关键词: International; Research; Fellowship; Program; Break

0301807TohverThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-four month research fellowship by Dr. Eric Tohver to work with Dr. Wilson Teixeira at the University of Sao Paulo in Sao Paulo, Brazil.This fellow will undertake a paleomagnetic and geochronological study of the late Precambrian sediments of the western Amazon craton in the western Brazilian states of Mato Grosso and Mato Grosso do Sul. These sediments record the opening of the Iapetus Ocean between ancestral North America and the Amazon craton during the break-up of the Rodinia supercontinent. Glacial sediments found in this rift sequence have been ascribed to a snowball Earth episode, a period of extreme climatic conditions linked to the break-up of Rodinia. Radiogenic dating using the 40 Ar/39Ar technique will be carried out on primary, authigenic minerals from these sediments in order to determine the timing of rifting as well as the age of the glacial event. These geochronological results will be used in conjunction with paleomagnetic data to establish the paleogeographic context of the glacial deposits. In addition, these data will be compared with those from North America to document the opening of the Iapetus Ocean. This project will establish the tectonic link between North and South America Precambrian times. These sediments present a unique opportunity to help resolve the ongoing debate regarding extreme climates proposed for end Precambrian times.The host, Dr. Teixeira is a leading expert in the Precambrian geology of South America and has recently established a new laboratory with laser extraction lines to complement the existing paleomagnetic laboratory, which utilized a field-free room and a 2G cryogenic magnetometer.

0301807Tohver国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该计划的奖项提供了联合研究的机会，以及使用国外独特或互补的设施，专业知识和实验条件。 该奖学金将资助Eric Tohver博士与Wilson特谢拉博士在巴西圣保罗的圣保罗大学进行为期24个月的研究。该研究员将对巴西西部马托格罗索州和南马托格罗索州的亚马逊克拉通西部的晚前寒武纪沉积物进行古地磁和地质年代学研究。 这些沉积物记录了在Rodinia超大陆分裂期间，位于祖先北美和亚马逊克拉通之间的Iapetus海洋的开放。 在这个裂谷序列中发现的冰川沉积物被归因于雪球地球事件，这是一段与Rodinia分裂有关的极端气候条件。 将对这些沉积物中的原生自生矿物进行放射性定年，以确定裂谷的时间以及冰川事件的年龄。 这些地质年代学结果将与古地磁数据结合使用，以建立冰川沉积物的古地理背景。 此外，这些数据将与来自北美的数据进行比较，以记录土卫八海洋的开放。 该项目将建立南北美洲前寒武纪时期之间的构造联系。 这些沉积物提供了一个独特的机会，以帮助解决目前正在进行的关于前寒武纪末期极端气候的争论。主持人特谢拉博士是南美洲前寒武纪地质学的领先专家，最近建立了一个新的实验室，配备激光提取线，以补充现有的古地磁实验室，该实验室使用了无场室和2G低温磁力计。