Low-grade metamorphic phosphate geochronology: High-precision dating of ancient crustal fluid flow, hydrothermal mineralisation and the "Great Oxidation Event"

低品位变质磷酸盐地质年代学：古代地壳流体流动、热液成矿和“大氧化事件”的高精度测年

• 批准号: DP0452196
• 负责人: Adj/Prof Birger Rasmussen
• 金额: $ 22.34万
• 依托单位: The University of Western Australia
• 依托单位国家: 澳大利亚
• 项目类别: Discovery Projects
• 财政年份: 2004
• 资助国家: 澳大利亚
• 起止时间: 2004-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://dataportal.arc.gov.au/RGS/Web/Grants/DP0452196
• 关键词: Low; grade; metamorphic; phosphate; geochronology

Reliable dating techniques are required to obtain precise ages for ancient crustal fluid flow. Current techniques suffer from inheritance and isotopic resetting, problems that are particularly pronounced in early Precambrian rocks. This project will employ new analytical techniques to date phosphate minerals recently identified as potentially important new chronometers of ancient fluid flow, providing the first precise tectonothermal history of the Archaean Pilbara Craton. The project will also establish the age of giant iron-ore deposits across the Hamersley Province, test the various models for iron-ore formation, and provide a minimum age for the oxidation of the Earth's surface.

需要可靠的测年技术来获得古地壳流体流动的精确年龄。目前的技术受到遗传和同位素重置的影响，这些问题在早期前寒武纪岩石中特别明显。该项目将采用新的分析技术，对最近被确定为古流体流动的潜在重要的新计时器的磷酸盐矿物进行测定，从而提供第一个精确的皮尔巴拉火山的构造历史。该项目还将确定哈默斯利省巨型铁矿床的年龄，测试各种铁矿形成模型，并提供地球表面氧化的最低年龄。