Role of Proterozoic and Paleozoic Volcanic Rocks in the Geologic Evolution of the Southeastern New England Avalon Zone

元古代和古生代火山岩在新英格兰东南部阿瓦隆带地质演化中的作用

• 批准号: 8721218
• 负责人: O. Hermes
• 金额: $ 4.76万
• 依托单位: University of Rhode Island
• 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: 1988-02-01 至 1991-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8721218&HistoricalAwards=false
• 关键词: Role; Proterozoic; Paleozoic; Volcanic; Rocks

Within the Appalachian orogenic belt, southeastern New England plays a key role in models for Appalachian orogenesis, because it contains one of the last accreted terranes and appears to have the most complete record of the Alleghanian Orogeny. Part of this history involves igneous activity, including late Proterozoic arc accretion, followed by episodic extensional quartz-rich alkalic magmatism throughout much of the Paleozoic succeeded finally by a brief period of peraluminous granite emplacement in the Permian. This study involves extensive zircon geochronology on two suites of volcanic rocks from the Avalon terrane. The study of these rocks may clarify crustal, tectonic and magmatic processes that occurred during the pre-collisional and early accretion stages of the Alleghanian orogenic episode of New England.

在阿巴拉契亚造山带内，新英格兰东南部在阿巴拉契亚造山模式中扮演着关键角色，因为它包含最后的吸积地体之一，似乎拥有阿勒格尼亚造山作用最完整的记录。这段历史的一部分涉及到火成岩活动，包括晚元古代的弧吸积作用，然后是贯穿古生代大部分地区的幕式伸展富石英碱性岩浆作用，最后是二叠纪短暂的过铝花岗岩侵位。这项研究涉及来自阿瓦隆地体的两套火山岩的广泛的锆石年代学。对这些岩石的研究可以阐明发生在新英格兰阿勒格尼亚造山幕的碰撞前和早期吸积阶段的地壳、构造和岩浆作用。