Thermal Structure of Archean Cratons

太古代克拉通的热结构

• 批准号: 8706599
• 负责人: Henry Pollack
• 金额: $ 5.32万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-06-15 至 1989-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8706599&HistoricalAwards=false
• 关键词: Thermal; Structure; Archean; Cratons

This is a study of the thermal structure of continental crations. The investigations will comprise (i) the measurement of terrestrial heat flow in both cratonic and rifted areas of central and southern Africa, (ii) comparative studies of the heat flow in and around the cratonic regions of Africa, North Amierica, Australia, and India, and (iii) numerical model studies of the effect of cratonic structure on regional heat transfer. African heat flow measurement program, previously focussed in Botswana and Namibia, will be extended into Zimbabwe, Tanzania, and Zaire. These countries collectively comprise both stable Archean cratonic terrains and rifted Proterozoic mobile belts of the East African Rift system. The new measurements will provide additional observations with which to test the hypothesis that thick cratonic roots devert mantle heat away from Archean terrains into younger surrounding mobile belts. Heat flow data from the Archean terrains of North America, Australia, and India will also be examined in the context of the cratonic diversion model. numerical models of heat transfer beneath and within cratonic and surrounding terrains will examine (a) the range of parameters that yield conditions consistent with observations of surface heat flow and mantle temperatures determined from thermobarometry, (b) the effects of cratonic scale on the diversion mechanism, and (c) the comparison of present day conditions to those in the Archean when heat production was 2-3 time greater, but temperatures in the cratonic root were similar to present-day values.

这是一个大陆热结构的研究， critions。 调查将包括（i）测量 地球热流在两个地幔和裂谷地区， （二）非洲中部和南部的比较研究， 在非洲、北大西洋和印度洋地区及其周围的热流 美国、澳大利亚和印度，以及（iii）数值模式 电子结构对区域热力影响的研究 转移 非洲热流测量计划，此前 集中在博茨瓦纳和纳米比亚，将扩展到津巴布韦， 坦桑尼亚和扎伊尔。 这些国家共同构成了 稳定的太古宙造山带和裂谷的元古代移动的 东非裂谷带 新测量结果 将提供额外的观察，以测试 厚地幔根转移地幔热量假说 从太古代的地形进入周围较年轻的移动的带。 来自北美太古代地形的热流数据， 澳大利亚和印度也将在 电子转移模型。 传热数值模型 地下和地下以及周围的地形将 检查（a）产生条件的参数范围 与地表热流和地幔的观测结果一致 由热压测定法确定的温度，（B） （c）关于分流机制的电子尺度; 与太古代相比， 生产是2-3倍，但温度在1000摄氏度 根是类似于今天的价值观。