RUI: Tectonic Investigations of Proterozoic Sedimentary Rocks in Central Madagascar and Implications for Late Precambrian Paleogeography

RUI：马达加斯加中部元古代沉积岩的构造研究及其对晚前寒武纪古地理的启示

• 批准号: 9814945
• 负责人: Rónadh Cox
• 金额: $ 17.98万
• 依托单位: Williams College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814945&HistoricalAwards=false
• 关键词: RUI; Tectonic; Investigations; Proterozoic; Sedimentary

9814945Cox The supercontinent Gondwana was being assembled during the late Proterozic, a time when fundamental changes were taking place in the earth's atmosphere, climate and biosphere. Madagascar, then in the center of Gondwana, is composed of precambrian crust that was metamorphosed and deformed during the assembly of Gondwana. Sedimentary rocks of the Itremo Group of central Madagascar offer the possibility to extract pre-orogenic sedimentation and paleogeography in addition to assembly-related tectonics. This study involves defailed lithogic and structural mapping of the Itremo Group outcrop belt in association with sedimentologic and petrologic analysis, with the aim of constraining provenance, sediment dispersal patterns, environments of deposition and ages of events so that a paleogeographic and tectonic model for central Madagascar can be constructed. Results are expected to provide information on the proterozoic continental shelf environment of Madagascar and will contribute to understanding pre-Gondwana paleogeography and the amalgamation of Gondwana. ***

9814945考克斯冈瓦纳超大陆在元古宙晚期形成，当时地球的大气层、气候和生物圈发生了根本性的变化。 马达加斯加岛位于冈瓦纳大陆的中心，由前寒武纪地壳组成，在冈瓦纳大陆的组装过程中变质变形。马达加斯加中部的伊特雷姆群的沉积岩提供了提取造山前沉积作用和古地理以及与组合有关的构造的可能性。 这项研究涉及到与沉积学和岩石学分析相关联的Itremo组露头带的详细岩性和构造制图，目的是限制物源、沉积物分散模式、沉积环境和事件年龄，以便可以构建马达加斯加中部的古地理和构造模型。 研究结果将为马达加斯加元古宙大陆架环境提供信息，并将有助于了解冈瓦纳古地理和冈瓦纳的融合。 ***