Development of 1.9 Ga Bear Creek Foredeep on Thermally YoungLithosphere

热年轻岩石圈上 1.9 Ga Bear Creek 前深部的发育

• 批准号: 8806090
• 负责人: John Grotzinger
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-02-15 至 1991-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8806090&HistoricalAwards=false
• 关键词: Development; 1.9; Ga; Bear; Creek

The proposed research will examine the possibility that Bear Creek Foredeep evolved on thermally young continental lithosphere as a result of collapse of an immature passive continental margin. Research will involve an integrated approach, combining geological and geochronological field investigations of selected areas with geophysical modelling of related gravity anomalies the Thelon Tectonic Zone (infered suture) and two-dimensional modelling of the basin - Thelon Zone system. Models will be used to make first-order predictions concerning basin geometry and stratigraphic architecture of basins formed on cold vs. warm lithosphere. The models will then be compared to the observed characteristics of Bear Creek Foredeep as a method of evaluating the thermal condition of the lithosphere during basin development. Evaluating the thermal age of the lithosphere during subsidence of Bear Creek Foredeep constitutes a critical test of the hypothesis that passive continental margins may have been, on the average, more short-lived than in younger times (cf. Hoffman and Bowring, 1984).

本研究将探讨熊溪前深在热年轻大陆岩石圈上演化的可能性，这是由于一个未成熟的被动大陆边缘的崩塌。研究将采用综合方法，将选定地区的地质和地质年代学实地调查与塞隆构造带相关重力异常的地球物理模拟（推断缝合）和盆地-塞隆带系统的二维模拟相结合。模型将用于对盆地几何形状和在冷与暖岩石圈上形成的盆地的地层结构进行一级预测。然后将这些模型与熊溪前深的观测特征进行比较，作为评价盆地发育过程中岩石圈热条件的一种方法。评估Bear Creek前深沉降期间岩石圈的热年龄构成了对被动大陆边缘平均而言可能比年轻时期更短暂这一假设的关键检验（参见Hoffman和Bowring， 1984）。