Comparison of fluvial and aeolian sedimentary environments based on morphological analysis of their mineral components

The relationship between depositional environments and transportation processes associated with the general properties of formed siliciclastic sediments has been of great interest to researchers. The recent spread of high-resolution analytical methods has allowed researchers to quickly examine grain shape properties of a large number of individual mineral grains. We investigated mineral particles of two sediment types from different depositional environments (wind-blown sand, floodplain and channel deposits [n=11]) from the Carpathian Basin (Central Europe) by using automated static image analysis (Malvern Morphologi G3SE-ID). Our aim was to determine the key variables that can help us distinguish fluvial and aeolian environments. During the analysis and data processing (e.g. hierarchical cluster analysis, Wilks’ λ, Kruskal-Wallis, MANOVA, PCA) we examined four variables related to grain shape which were the following circularity (form), convexity (surface texture), solidity (roundness) and elongation (form).

The objective and the quantitative study revealed that the solidity parameter proved to be an effective variable for separating sediments with similar convexity values (mean: 0.95-0.99) like in our case, the aeolian and fluvial sediments. Fluvial sediments had lower solidity (mean: 0.95-0.97) values compared to the aeolian sands (mean: 0.97-0.98). This major difference (p<0.001; α=0.05) resembles that the investigated fluvial sediments are not as much rounded as aeolian sands. Associated with circularity (form) result, it can be deduced that grains from fluvial sediments (low circularity; mean: 0.76-0.84) spent less time in the transport media or transported at lower energy level than aeolian grains (high circularity; mean: 0.82-0.87). Our research supports the previously established theory that aeolian transport is more effective in rounding the grains than an aqueous environment.

Support of the National Research, Development and Innovation Office (Hungary) under contract FK138692, ÚNKP-22-3 and RRF-2.3.1-21-2022-00014 are gratefully acknowledged.