Abstract

This study shows that fugitive emissions associated with the surface mining of phosphate rock are a significant phosphorus (P) source to surface soils in northeastern Utah. Phosphorus is a nonrenewable resource essential for all life. Anthropogenic alterations to the P-cycle have led to widespread P pollution, and the unsustainable management of P has led to the threat of global depletion of P resources. Thus, accounting for both natural and anthropogenic flow paths of P is essential for the conservation and pollution reduction of P. One such source of human alteration to the P-cycle is the mining of phosphate rock. Mining, however, has many adverse environmental effects, including widespread fugitive dust emissions. Dust collection in the Ashley National Forest of northeastern Utah, proximate to a surface P mine, has measured P concentrations in dust more than four times that of other regional samples. This suggests that mining emissions may alter the natural P loading of the soils in the National Forest through dust deposition; however, no research has been done to identify the abundance and range of mine-attributable P enrichment in the soils surrounding phosphate mining activities. The combined geospatial and geochemical approach of this study shows that surface soil P concentrations were found to be enriched above naturally occurring levels up to 6 km from mining activity (enrichment factor (EF) > 1), with the most significant enrichment occurring within the first 1 km (EF > 2). Phosphorus concentrations and EF levels averaged a decrease of 23.5% from surface to subsurface soil. Geochemical fingerprinting techniques, including elemental correlations and X-ray diffraction, found that P concentrations had a strong positive relationship with calcium (R2=0.54) and that the mineral composition of P-enriched soils resembled the ore from the local P mine, linking the observed P enrichment in the forest to the calcium-phosphate rich ore. This study has shown that fugitive emissions from P mining result in significant enrichment of forest soils and potentially contribute to upstream P pollution. The results reveal the previously unrealized impact of fugitive mining emissions altering soil nutrient loading in subalpine soils. As future global demand for P increases, it is imperative that appropriate fugitive dust mitigation techniques are used to minimize the impacts of mining on P loading in nearby ecosystems.

Degree

MS

College and Department

Computational, Mathematical, and Physical Sciences; Geological Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2024-08-15

Document Type

Thesis

Keywords

phosphorus, dust, pollution, enrichment factor, mining, phosphorus cycle, subalpine soil, geochemistry, Uinta Mountains, soil chemistry, speciation, geospatial

Language

english

Download

Share

COinS