Tectonothermal Evolution of the Cadomian Orogen in the North Armorican Massif and Circum-Atlantic Correlations

北阿莫里坎地块卡多米亚造山带的构造热演化与环大西洋关系

• 批准号: 9017271
• 负责人: R. David Dallmeyer
• 金额: $ 11.01万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-15 至 1995-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9017271&HistoricalAwards=false
• 关键词: Tectonothermal; Evolution; Cadomian; Orogen; North

The North Armorican Massif is part of the Armorican Plate that separated from N. America, Baltica and Gondwana in the early Paleozoic. Large segments of Armorica were affected by the late Precambrian Cadomian orogeny, and the massif is one of very few areas where there is no apparent overprinting of Cadomian aged rocks during the late Paleozoic Variscan orogeny. This area is thus critical for resolution of tectonic linkages with correlative Avalonian and/or Pan-African sequences. Existing models for the Cadomian orogeny have a limited geochemical data base, although recent field work has shown that complex polyphase Precambrian metamorphic/structural events occurred. This study will make systematic determination of 40Ar/39Ar mineral ages and selected U-Pb zircon ages from representative lithological units within the massif, and will be conducted in collaboration with British field geologists working in the area. Co-operation with local French geologists has been arranged. The results of this research will permit detailed evaluation of Precambrian tectonothermal events and will help constrain tectonic models for the region.

北阿莫里肯地块是阿莫里肯板块的一部分， 与N分离。早期的美洲、波罗的海和冈瓦纳 古生代的。 大部分的阿莫里卡受到了后期的影响， 前寒武纪的Cadomian造山带， 没有明显的加多米年龄的地区 晚古生代华力西造山运动时期的岩石。 这方面 因此，对于解决与相关的构造联系至关重要 阿瓦隆和/或泛非洲层序。 现有的模型， Cadomian造山带的地球化学数据库有限， 最近的野外工作表明，复杂的多相前寒武纪 发生了变质/构造事件。 这项研究将使 ~（40）Ar/~（39）Ar矿物年龄系统测定及部分U-Pb 代表性岩石单元的锆石年龄 地块，并将与英国领域合作进行 在该地区工作的地质学家。 与当地法国人合作 地质学家已经安排。 这项研究的结果将 允许详细评估前寒武纪构造事件， 将有助于限制该地区的构造模型。