Analysis of Factors Controlling the Distribution of Trace Elements in Surface Sediments of Coastal Alabama

One hundred sixteen sediment samples were collected on a 4 km grid from Mobile Bay, the eastern Mississippi Sound, and bays and rivers adjoining these water bodies. The sediment samples were analyzed for mineralogy and the extractable concentrations of 28 chemical elements (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, Pb, Se, Si, Sb, Ag, Na, Sn, Sr, Ti, Tl, V, and Zn). The main minerals found via Rietveld refinement of XRD patterns in these samples were quartz, illite, kaolinite, chlorite, microcline, albite, pyrite, and mixed high CEC (cation exchange capacity) clays. Sediment extractable element concentrations and mineral percentages were compared with bottom water field measurements, sediment particle size data and total organic carbon (TOC) contents. Correlation coefficients were calculated for pairs of each of these variables in three different sample groups, as well as the full sample set and compiled into correlation matrices. The strongest correlations found were between TOC, particle size variables, and element concentrations for Al, Ba, Be, Co, Cr, K, Fe, Mg, Ni, Pb, V, and Zn. Maps were created to portray spatial distribution of element concentrations, minerals, and TOC throughout Mobile Bay and the eastern Mississippi Sound, many of which showing similar patterns. Principal component analysis (PCA) of the data set was performed to determine controls on the distribution of trace elements in surface sediments of the study area. PCA indicates that the main controls on the dataset are total surface area of sediment particles, relative abundance of high CEC clays in sediment, and salinity of bottom water at sample locations.

Grantor dc:publisher

University of Alabama Libraries

Year dc:date.issued

2025

Author dc:creator

• Young, Steven

Advisor dc:contributor.advisor

• Donahoe, Rona

Contributors dc:contributor

• Dimova, Natasha
• Lu, Yuehan
• Jones, Stephen

Statement dc:rights

• All rights reserved by the author unless otherwise indicated.

Language dc:language.iso

en_US, English

Dc Identifier Other

1120855

OAI identifier oai:identifier

oai:ir.ua.edu:123456789/16609