Arsenic and Molybdenum in Marine Carbonates: Redistribution, Binding Forms and Isotope Systematics

沉积序列中的微量元素既可以是福也可以是祸。它们是一件幸事，因为（1）它们的浓度模式可以用作重建沉积时环境条件的替代物，（2）它们可以提供有关成岩过程的信息，（3）它们可以被开采以满足战略矿物需求。与此同时，它们可能是一种诅咒，因为由于水-岩石相互作用，它们可以转移到地下水中，在那里它们对这一关键资源的运营和健康方面有害。令人惊讶的是，我们对碳酸盐沉积物中的两种微量元素As和Mo知之甚少。这似乎令人惊讶，因为碳酸盐岩是最丰富的沉积岩类型之一，As和Mo是具有相当大的生态和科学意义的元素。为了促进我们的理解，拟议的研究的总体目标将是解开成岩历史和随之而来的重新分配的As和Mo在Floridan含水层系统的碳酸盐基质。将这些信息与详细的矿物学观察相结合，将改进反应性运输模型，并有助于确定潜在污染的地区，区域和年龄，这将有助于安全饮用水的探索。了解负责钼及其同位素的再分配的过程应该提供一个工具，重建古海洋环境中的条件比富氧盆地。

Trace elements in sedimentary sequences can be both a blessing and a curse. They are a blessing because (1) their concentration patterns can be used as proxies for the reconstruction of environmental conditions at the time of deposition, (2) they can provide information about diagenetic processes, and (3) they can be mined to meet strategic mineral needs. At the same time, they can be a curse because due to water-rock interaction, they can be transferred into groundwater, where they are detrimental to operational and health aspects of this critical resource. We know surprisingly little about the two trace elements As and Mo in carbonate sediments. This seems surprising since carbonates are among the most abundant sedimentary rock types and As and Mo are elements of considerable ecological and scientific interest. To advance our understanding, the proposed study's overarching objective will be to unravel the diagenetic history and the concomitant redistribution of As and Mo in the Floridan Aquifer System's carbonate matrix. Combining that information with detailed mineralogical observations will improve reactive transport models and help identify areas, regions, and ages of potential contamination, which will aid exploration for safe drinking water. Understanding the processes responsible for the redistribution of Mo and its isotopes should provide a tool for reconstructing paleo conditions in marine environments other than euxinic basins.