Researcher ORCID Identifier
https://orcid.org/
0000-0002-4513-1333
Graduation Year
2022
Date of Submission
4-2022
Document Type
Open Access Senior Thesis
Degree Name
Bachelor of Arts
Department
Environmental Analysis
Reader 1
Colin Robins
Reader 2
Donald McFarlane
Rights Information
© 2022 Isabela M Overturf
Abstract
Human decomposition is studied to aid forensic investigations and better understand the impact of cemeteries on urban resources like soil and groundwater. The purpose of this study was to identify changes in soil geochemistry at and around a human grave to search for lateral nutrient movement and possibly identify new patterns in elemental concentrations that could be used in estimating post-mortem intervals (PMIs). At the Forensic Anthropology Research Facility (FARF) at Texas State San Marcos, soil samples were collected from a shallow grave over the course of 54 days to conduct analysis for organic matter content, texture, pH, and bulk elemental concentrations in native central Texas soils. East Texas soils were also brought in and placed underneath the body for comparative analysis. Organic matter content sharply increased at the beginning of the observation period before steadily declining, while pH showed the opposite trend. There was an initial decrease in pH, followed by significant increases under and around the body towards the end of the study. At a 25 cm distance from the body, there were significant changes in the soil content of Fe, Ca, and Al, with trends for Fe and Al over time both under and around the body showing promise as a potential chemical marker to aid in estimating PMI. This indicates a lateral migration of nutrients in the soil, likely as a result of bioturbation in the soil by microfauna. Further study of these indicators, especially on uncovered and more deeply buried bodies, could provide the more robust statistics necessary to consider Fe and Al concentrations in the soil when estimating how long a decomposing body may have been present. Investigation of more chemical indicators may be crucial in the future of missing and murdered persons cases, and it informs the body of knowledge relating to effects of cemeteries on the environment and nearby populations.
Recommended Citation
Overturf, Isabela Marisol, "Spatial Geochemical Changes in Central and East Texas Soils over Time Resulting from Human Decomposition" (2022). CMC Senior Theses. 3003.
https://scholarship.claremont.edu/cmc_theses/3003
Included in
Biogeochemistry Commons, Environmental Chemistry Commons, Environmental Indicators and Impact Assessment Commons, Geochemistry Commons, Life Sciences Commons, Other Environmental Sciences Commons
