Paleomagnetic and 40Ar/39Ar Investigations into the Origin of Late Proterozoic Mobile Belts in South America and Africa

南美洲和非洲晚元古代活动带起源的古地磁和 40Ar/39Ar 调查

• 批准号: 8805529
• 负责人: Tullis Onstott
• 金额: $ 4.5万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-15 至 1990-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8805529&HistoricalAwards=false
• 关键词: Paleomagnetic; 40Ar; 39Ar; Investigations; into

Many of the precambrian shields or cratons are transgressed by "mobile belts" that have been the loci of deformation and metamorphism subsequent to craton formation. These belts are generally consistent with an origin by plate collision at former plate margins, however, the style and relative displacements associated with these collisions are not well constrained. This renewal will continue a paleomagnetic and Ar/Ar age dating program from rock units on opposite sides of the Brasilian mobile belt. Results, combined with existing data from the extension of the Brazilian belt in west Africa, the Pharusian belt, will allow assessment of the displacement and timing associated with a possible late Proterozoic continental collision.

许多前寒武纪盾或克拉通被“活动带”所侵，这些“活动带”是克拉通形成后变形和变质的场所。这些带通常与原板块边缘板块碰撞的起源相一致，然而，与这些碰撞有关的样式和相对位移并没有得到很好的约束。这次更新将继续从巴西活动带两侧的岩石单元进行古地磁和Ar/Ar年龄定年程序。研究结果，结合巴西带在西非延伸的现有数据，将可以评估与可能的晚元古代大陆碰撞相关的位移和时间。