Systematics, development and applications of sulfide mineral geochronology using rhenium-osmium isotopes

铼锇同位素硫化物矿物地质年代学的系统学、发展和应用

• 批准号: RGPIN-2017-04288
• 负责人: Creaser, Robert
• 金额: $ 4.23万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710464
• 关键词: Systematics; development; applications; sulfide; mineral

The proposed research is focused on geochronology - the science of determining absolute geological time using radioactive decay. It will develop, test and apply the 187Re-187Os radioactive decay scheme to date sulfide minerals that form in economically-important ore deposits of copper, lead and zinc from Canada and other locations internationally. The research has the potential to develop tools that will revolutionize our understanding of when these ores form, and thereby better identify how these ores form to identify the causative geological processes and events that formed ore. Testing the accuracy and reliability of these mineral chronometers is a critical and integral part of the work proposed. Not all minerals yield accurate geological ages, and defining the conditions for which minerals do and don't yield accurate ages is an essential part of the planned research program. Rigorous testing will include two of the most common sulfide minerals; pyrite and chalcopyrite, to evaluate how they behave during episodes of younger thermal disturbance. Copper is a critical metal in modern society, but the origin of some ores of copper formed in sedimentary basins is poorly understood. A second objective will test whether the copper sulfide minerals provide meaningful age information using Re-Os isotopes by firstly undertaking systematic projects, and then applying the knowledge gained to sediment-hosted copper ore deposits to better understand their formation mechanisms and processes. Regional-scale fluid flow in Earth's sedimentary basins forms important metallic ores of zinc and lead, and can contribute to porosity development in petroleum reservoirs, but the underlying causes of fluid flow remain controversial. Proposed research will develop the mineral pyrite as a chronometer to test competing ideas for the geological processes that drive fluid flow in sedimentary basins. The derived ages of ore formation will allow a far better understanding of the often complex series of processes required to form these critical resources, and allow geologists to test and evaluate competing hypotheses for ore formation. In turn, this may allow minerals exploration programs to better identify prospective and non-prospective areas of Earth's crust for evaluation of resource potential.

拟议的研究重点是地质年代学-利用放射性衰变确定绝对地质时间的科学。它将开发、测试和应用187 Re-187 Os放射性衰变方案，以确定加拿大和国际其他地区具有重要经济意义的铜、铅和锌矿床中形成的硫化物矿物的年代。这项研究有可能开发出工具，彻底改变我们对这些矿石何时形成的理解，从而更好地识别这些矿石是如何形成的，以确定形成矿石的地质过程和事件。 测试这些矿物计时器的准确性和可靠性是拟议工作的一个重要组成部分。并非所有矿物都能产生准确的地质年龄，确定矿物产生和不产生准确年龄的条件是计划研究计划的重要组成部分。严格的测试将包括两种最常见的硫化物矿物：黄铁矿和黄铜矿，以评估它们在较年轻的热扰动期间的行为。铜是现代社会的一种重要金属，但沉积盆地中形成的一些铜矿石的起源却知之甚少。第二个目标将首先开展系统性项目，然后将所获得的知识应用于沉积物型铜矿，以更好地了解其形成机制和过程，从而使用Re-Os同位素测试硫化铜矿物是否提供有意义的年龄信息。地球沉积盆地中的区域尺度流体流动形成了重要的锌和铅金属矿，并有助于石油储层中的孔隙发育，但流体流动的根本原因仍然存在争议。拟议的研究将开发矿物黄铁矿作为计时器，以测试驱动沉积盆地流体流动的地质过程的竞争思想。 由此得出的成矿年龄将有助于更好地理解形成这些关键资源所需的一系列复杂过程，并使地质学家能够测试和评估成矿的竞争假设。反过来，这可以使矿产勘探计划更好地确定地壳的远景和非远景区域，以评估资源潜力。