Loess provenance in Bosiljevski, Croatia Terra Rossa Formations through SEM Based Mineralogical Analysis

Session: 37th Annual Undergraduate Research Exhibition Sponsored by Sigma Gamma Epsilon (Posters)

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Abstract:

Terra Rossa soils are a distinct and relatively widespread feature of Mediterranean karst terrains, and are characterized by reddish colorations and clayey-silty textures, which overlie exposed carbonate bedrock. Considered mostly to be polygenetic relict soils, these profiles provide a history of partial depositions and different periods of stratigraphic growth that are unique to this karst soil environment. One home of these soils is the Istrian Peninsula of Croatia. Here, there is a preserved stratigraphic record of the depositional history of the area, reflective of the climatic and environmental changes over the Quaternary. This project focuses on sampling from Bosiljevski, Karlovac County, Croatia, where the Terra Rossa formation is reflective of the loess depositions and local bedrock weathering in the area. 

The primary objective of this project is the continuation of  investigating the provenance of sediments contributing to the loess and paleosol development in the region. This effort seeks to expand the current understanding of sedimentation pathways in the region and their origins. It is aimed to identify patterns and similarities between the soil horizons found in Bosiljevski with those found across other Istrian sites.  Using in situ sampling, an identified five soil horizons were sampled. Epoxy mounts of all five horizons, as well as slabs of underlying bedrock will be studied using FIB-SEM equipment, primarily focusing on mineralogical analysis using tools including EDS and BSE analysis. These methods will be used to determine modes and abundance of clay and silt fractions. This data will be added to the larger pool of data on Istrian TRs, and additionally be compiled with other techniques done on the same samples with collaborators at the University of Zagreb.

Research on these environments is the foundation for longer term use to climate reconstruction. By better constraining the origins of the sediment sources that infill the terra rossa profiles in the Istrian area, it contributes to the broader efforts looking to reconstruct the evolution of the Quaternary landscape, and enhances understanding of mediterranean pedogenesis under changing climatic conditions. Additional insight is aimed to help look at climatic controls on soil developments in regional karst terrains, allowing for enhanced understanding of possible fluctuations in glacial-interglacial conditions, while also providing comparative data for other global karst soil systems, and TR systems in general.