Experimental carbonate geochemistry and early diagenesis

实验碳酸盐地球化学和早期成岩作用

基本信息

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

项目摘要

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。该方法使用现场研究，受控实验室实验和建模。我的研究将在两个方面进行：碳酸盐地球化学和沉积物成岩作用。这两个程序是密切联系的，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和它们沉淀的溶液的化学性质的代理。碳酸盐矿物质的表面具有高度反应性，并且在确定各种水生环境（含水层，沉积物，矿山尾矿）中的痕量元素的迁移率中起着重要作用。长期目标是在各种环境条件下开发一种吸附（吸附和共同吸附）行为的预测模型（吸附和共沉淀）行为和反应性。除了“理想”矿物表面的反应外，我计划采用更务实的方法，并研究细菌对碳酸盐矿物质反应动力学和矿物学的影响。细菌在水生环境中无处不在，可以在大多数矿物表面上找到，但是，尚未正确研究它们对风化速率的影响和碳酸盐沉淀的矿物质学。通过海洋水柱燃料沉降，参与并受到沉积物中许多生物地球化学过程的颗粒。该研究计划的长期目标是确定控制跨沉积物 - 水界面元素通量的因素，并更好地利用沉积物记录来推断古环境条件。我将重点介绍沉积物中选定的氧化还原敏感元件（例如Fe，Mn，Mo，U和Re）的地球化学行为，在各种氧合条件下它们如何集中或在沉积物中耗尽的速度以及如何在沉积物中耗尽沉积物，以及它们在沉积物中的分布如何使用来推断过去的深度效果环境的条件。