Late Precambrian Epeirogenic Uplift and Erosion of Southern Canadian Shield

晚前寒武纪表成隆升和加拿大南地盾侵蚀

• 批准号: 8916290
• 负责人: Kevin Crowley
• 金额: --
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-02-01 至 1992-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8916290&HistoricalAwards=false
• 关键词: Late; Precambrian; Epeirogenic; Uplift; Erosion

The Canadian Shield is an extensive bedrock plain of low relief that covers the northern United States and most of Canada. The exposed rocks are among the oldest on earth and were formed generally at elevated temperatures and pressures. The topo- graphic shield was formed by a broad uplift of the North American continent between about 1.6 and 0.5 billion years ago. The cause and timing of uplift is unknown: the only direct evidence for uplift is the presence of a 1 billion year erosional hiatus. The objective of this project is to reconstruct the uplift history of the shield during this erosional hiatus by measuring the apatite fission track cooling histories of surface samples collected from the shield in Ontario and adjacent areas. Results are expected to constrain the timing and rate of uplift which are important clues to the causes of the widespread uplift.

加拿大地盾是一个覆盖美国北部和加拿大大部分地区的广阔的低浮雕基岩平原。裸露的岩石是地球上最古老的岩石之一，通常是在高温高压下形成的。地形盾是由16亿到5亿年前北美大陆的广泛隆起形成的。隆起的原因和时间是未知的：隆起的唯一直接证据是存在一个10亿年的侵蚀中断。该项目的目的是通过测量从安大略省和邻近地区收集的盾层表面样品的磷灰石裂变径迹冷却历史，重建在这一侵蚀间隙期间盾层的隆起历史。研究结果有望限制隆起的时间和速率，这是研究广泛隆起原因的重要线索。