Experimental carbonate geochemistry and early diagenesis

实验碳酸盐地球化学和早期成岩作用

• 批准号: 39679-2013
• 负责人: Mucci, Alfonso
• 金额: $ 3.5万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634063
• 关键词: Experimental; carbonate; geochemistry; early; diagenesis

My research focuses on the mechanisms and rates of biogeochemical processes in aquatic systems. The approach uses field studies, controlled laboratory experiments, and modeling. My research will be carried out on two fronts: carbonate geochemistry and sediment diagenesis. The two programs are intimately linked since carbonate minerals are common constituents of sediments and widely used as proxies to infer the paleo-environmental conditions and the chemistry of the solutions from which they precipitated. The surfaces of carbonate minerals are highly reactive and play an important role in determining the mobility of trace elements in a variety of aquatic environments (aquifers, sediments, mine tailings). The long-term objective is to develop a predictive model of the sorption (adsorption and co-precipitation) behavior and reactivity of carbonate minerals under various environmental conditions. In addition to reactions at "ideal" mineral surfaces, I plan to take a more pragmatic approach and investigate the influence of bacteria on carbonate mineral reaction kinetics and mineralogy. Bacteria are ubiquitous in aquatic environments and can be found on most mineral surfaces, yet, their influence on weathering rates and the mineralogy of carbonate precipitates has not been properly investigated. Particles that settle through the oceanic water column fuel, participate in, and are subjected to, a number of biogeochemical processes in the sediment. The long-term goal of this research program is to identify factors that control elemental fluxes across the sediment-water interface and better exploit the sedimentary record to infer paleo-environmental conditions. I will focus on the geochemical behaviour of selected redox-sensitive elements (e.g. Fe, Mn, Mo, U, and Re) in sediments, how and how fast they are concentrated or are depleted in sediment under various conditions of oxygenation and how their distribution in the sediment can be used to infer the conditions of past depositional environments.

我的研究重点是水生系统中生物地球化学过程的机制和速率。该方法采用实地研究、受控实验室实验和建模。我的研究将在两个前沿进行：碳酸盐地球化学和沉积物成岩作用。这两个项目密切相关，因为碳酸盐矿物是沉积物的常见成分，并广泛用作推断古环境条件及其沉淀溶液的化学成分。碳酸盐矿物的表面具有高反应性，在确定各种水生环境（含水层、沉积物、尾矿）中微量元素的流动性方面发挥着重要作用。长期目标是开发碳酸盐矿物在各种环境条件下的吸附（吸附和共沉淀）行为和反应性的预测模型。除了“理想”矿物表面的反应之外，我还计划采取更务实的方法，研究细菌对碳酸盐矿物反应动力学和矿物学的影响。细菌在水生环境中无处不在，并且可以在大多数矿物表面上找到，然而，它们对风化速率和碳酸盐沉淀物矿物学的影响尚未得到适当的研究。通过海洋水柱燃料沉降的颗粒参与并受到沉积物中的许多生物地球化学过程的影响。该研究计划的长期目标是确定控制沉积物-水界面元素通量的因素，并更好地利用沉积记录来推断古环境条件。我将重点关注沉积物中选定的氧化还原敏感元素（例如铁、锰、钼、铀和铼）的地球化学行为，它们在各种氧化条件下在沉积物中浓缩或耗尽的方式和速度，以及它们在沉积物中的分布如何用于推断过去沉积环境的条件。