Collaborative Research: Testing Models of Calcite Microcrystal Diagenesis Through Experiments, Geochemistry, and Advanced Imaging

地下地质水库中的资源是社区、公司和国家经济活动和活力的关键。为了以经济有效的方式开发这些资源，了解这些岩石的管道系统是至关重要的，特别是岩石中的孔隙（开放空间）有多大，它们连接得有多好，以及它们容纳了什么样的流体。这项研究的重点是小孔，称为微孔，以了解它们是如何形成的，以及它们在埋在地球中时如何变化。这些知识将使农民、水厂管理人员以及石油和天然气行业的人们能够钻更少的威尔斯井，提高他们的经济竞争力，减少对环境和人类的干扰。微孔也是用破碎的石灰石建造的道路过早恶化的原因。因此，这项工作的结果可能会导致更强大的高速公路，降低建设和维护成本，同时为驾驶员提供更安全，更顺畅的行驶。以前的工作表明，大多数微孔托管在方解石微晶的框架。目前的研究旨在了解石灰岩中这些微晶的纹理的基本控制。方解石微晶的形成和演化有许多普遍的途径。然而，没有人把微晶结构与成岩作用联系起来。我们的目的是整合实验室实验，先进的成像和高分辨率的地球化学技术，以更好地了解方解石微晶的成岩作用，从而它们之间的微孔。具体而言，我们建议使用实验和各种各样的天然样品来评估各种方解石微晶结构的地球化学异质性和成因演化。我们假设微晶化学的空间变化将揭示不同的微晶结构与沿着增加胶结作用的成岩轨迹的位置相关（即，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The resources contained in underground geologic reservoirs are key to the economic activity and vitality of communities, companies, and countries. To develop these resources in a cost-effective manner, it is vital to understand the plumbing of these reservoirs-specifically how big the pores (open spaces) are in the rocks, how well they are connected, and what kind of fluids they hold. This study focuses on small pores, called micropores, to understand how they form, and how they change as they are buried in the Earth. This knowledge will allow people such as farmers, water plant managers, and the oil and gas industry to drill fewer wells, increasing their economic competitiveness and decreasing disturbances to the environment and people. Micropores are also responsible for premature deterioration of roads constructed with crushed limestone. Therefore, the results from this work could lead to more robust highways, reducing construction and maintenance costs, while providing a safer and smoother ride for drivers. Previous work shows that most micropores are hosted in a framework of calcite microcrystals. The current research aims to understand the fundamental controls on the textures of these microcrystals in limestones. Numerous generalized pathways for calcite microcrystal formation and evolution have been proposed. None, however, has tied microcrystal texture to diagenetic process in a robust manner. Our aim is to integrate laboratory experiments, advanced imaging, and high-resolution geochemical techniques to better understand the diagenesis of calcite microcrystals and thus the micropores between them. Specifically, we propose to use experiments and a wide variety of natural samples to assess the geochemical heterogeneity and genetic evolution of the various calcite microcrystal textures. We hypothesize that spatial variations in microcrystal chemistry will reveal that the different microcrystal textures correlate to positions along a diagenetic trajectory of increasing cementation (i.e., microcrystal textures become more fitted with progressive burial and cementation).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.