The key to quantifying chemical weathering intensity: clay stable isotope fractionation factors

量化化学风化强度的关键：粘土稳定同位素分馏因子

• 批准号: NE/M001865/1
• 负责人: Edward Tipper
• 金额: $ 59.43万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FM001865%2F1
• 关键词: key; quantifying; chemical; weathering; intensity

Chemical weathering is the process by which rocks dissolve in contact with natural waters. This process of dissolution supplies nutrients to plants, solutes to waters (of the kind you might find on the label of a bottle of mineral water) and delivers nutrients to the oceans via rivers and groundwaters. These nutrients are used by algae and microscopic plankton to grow, including the growth of shells of marine fauna which are made from calcium carbonate. This coupled process of mineral dissolution on the continents and biogenic calcium carbonate formation in the oceans plays a key role in regulating the global carbon cycle, transferring carbon from the atmosphere to the carbonate rock reservoir, when shells become buried as sediments. Geologists think that this simple series of reactions has played a pivotal role in regulating the carbon cycle and hence climate over Earth's history.Critical to this series of processes are clays. Rocks don't simply just dissolve in rainwater, they break down slowly, and their transformation into solutes happens in a stepwise manner via the formation of new minerals, frequently clays. Clays are a very common mineral and present in soils and rocks in the world all around us. We seek to use novel chemical methods to understand how clays are important to the processes of chemical weathering, exploiting recent technological advances that allow us to measure very precisely isotope ratios of the key elements in clay formation, magnesium, silicon and lithium. Different isotopes of an element, have very small differences their mass because of additional neutrons in their nuclei. Geochemists can measure small differences in the amount of these isotopes and from these differences infer key points about how the clays are being made. Importantly these isotopes are fractionated when clays crystallise in the natural world, but this is poorly understood. To improve our understanding, we seek to make artificial clays in the laboratory, where we can control all the conditions of formation carefully, and observe how the isotopes behave. With our detailed understanding of how the isotopes behave in the laboratory, we will then apply this knowledge to the natural world, where we will gain a much better understanding of chemical weathering, and how the carbon cycle, and hence climate has behaved over Earth history.

化学风化是岩石在与天然水接触时溶解的过程。这个溶解过程为植物提供营养物质，向水中溶解物质(你可以在瓶子矿泉水标签上找到的那种)，并通过河流和地下水将营养物质输送到海洋。这些营养物质被藻类和微小的浮游生物用来生长，包括由碳酸钙制成的海洋动物贝壳的生长。这一大陆矿物溶解和海洋中生物成因碳酸钙形成的耦合过程在调节全球碳循环方面发挥了关键作用，将碳从大气转移到碳酸盐岩储存库，当贝壳作为沉积物被埋藏时。地质学家认为，这一简单的一系列反应在调节地球历史上的碳循环和气候方面发挥了关键作用。对这一系列过程至关重要的是粘土。岩石不只是简单地溶解在雨水中，它们会慢慢分解，它们通过形成新的矿物，通常是粘土，以一种循序渐进的方式转化为溶质。粘土是一种非常常见的矿物，存在于我们周围的土壤和岩石中。我们寻求使用新的化学方法来了解粘土对化学风化过程的重要性，利用最近的技术进步，使我们能够非常精确地测量粘土形成过程中关键元素镁、硅和锂的同位素比率。一种元素的不同同位素，由于其原子核中有额外的中子，其质量差别非常小。地球化学家可以测量这些同位素数量的微小差异，并从这些差异中推断出粘土是如何形成的关键问题。重要的是，当粘土在自然界结晶时，这些同位素会被分馏，但人们对此知之甚少。为了提高我们的理解，我们试图在实验室里制作人造粘土，在那里我们可以仔细控制所有的形成条件，并观察同位素的行为。随着我们对同位素在实验室中的行为有了详细的了解，我们将把这些知识应用到自然界，在那里我们将更好地了解化学风化，以及碳循环，因此气候在地球历史上是如何表现的。

项目成果

Experimental constraints on Li isotope fractionation during clay formation

• DOI: 10.1016/j.gca.2019.02.015
• 发表时间: 2019-04
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: R. Hindshaw;Rebecca Tosca;Thomas L. Goût;I. Farnan;N. Tosca;E. Tipper

Decoupling of dissolved and bedrock neodymium isotopes during sedimentary cycling

沉积循环过程中溶解的和基岩的钕同位素的解耦

• DOI: 10.7185/geochemlet.1828
• 发表时间: 2018
• 期刊: Geochemical Perspectives Letters
• 影响因子: 4.9
• 作者: Hindshaw R

Rare earth element and neodymium isotope tracing of sedimentary rock weathering

• DOI: 10.1016/j.chemgeo.2020.119794
• 发表时间: 2020-10-20
• 期刊: CHEMICAL GEOLOGY
• 影响因子: 3.9
• 作者: Bayon, Germain;Lambert, Thibault;Tipper, Edward T.
• 通讯作者: Tipper, Edward T.

Temperature dependent lithium isotope fractionation during glass dissolution

• DOI: 10.1016/j.gca.2021.09.005
• 发表时间: 2021-11
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: Thomas L. Goût;Madeleine Bohlin;E. Tipper;G. Lampronti;I. Farnan

Clay mineralogy, strontium and neodymium isotope ratios in the sediments of two High Arctic catchments (Svalbard)

• DOI: 10.5194/esurf-6-141-2018
• 发表时间: 2017-09
• 作者: R. Hindshaw;N. Tosca;A. Piotrowski;E. Tipper