Palaeoenvironmental applications of chromium and aluminium: Concerns on partitioning and early diagenetic remobilization

Abstract

Sequential extraction of core samples collected from Pulicat Lake, east coast of India, showed that on average, 59% of labile Cr and 28% of labile Al remain adsorbed onto Fe-Mn oxides. Similarly, 61% of labile Al and 36% of labile Cr are associated with organic matter. Cross-correlation analysis revealed that in the Fe-Mn oxides phase, Cr primarily exists with Mn-oxides, while Al remains mainly adsorbed onto Fe-oxides.Factor analysis revealed four factors that could explain 82% of the variance in the data. Changes in water column ionic composition, salinity, dissolution of Fe-Mn oxides during microbial oxidation of organic matter, changes occurring to the organic matter and calcium carbonate during early diagenesis are the key factors influencing the Al and Cr concentrations in the labile fractions. The results of this study are useful to interpret palaeoenvironmental conditions.

Introduction to Geochemistry of Sedimentary Systems: Current trends and applications

“…According to this study, the authors were able to document the high-variability of Fe than Cd among the total heavy metal concentrations in the detrital components of the estuarine surface sediment. In addition, based on enrichment factors and other calculations, a significant increase of probably toxic elements was noticed during the post-monsoon season.Based on employing sequential extraction of Cr and Al from core sediments recovered from a coastal brackish lake, Eswaramoorthi, Subramanian,Nagarajan, and Periakali (2021) examine the partitioning and early diagenetic remobilization characteristics. These authors have interpreted major control of changes in water column ionic composition, salinity, and interactions with organic matter over the concentrations of Al and Cr in the labile fractions.…”