Implications of the geochemistry of L1LL1 (MIS2) loess in Poland for paleoenvironment and new normalizing values for loess-focused multi-elemental analyses

Loess paleoenvironmental reconstructions on regional to supra-regional scales have recently gained much attention. Geochemistry comparisons in relation to reference datasets, such as the Upper Continental Crust (UCC) data, have furthered our understanding of the climatic and geomorphological conditions under which terrestrial sites have developed. However, UCC data differs from loess, thereby obscuring important features, and the existing “average loess” datasets also are not sufficient for modern investigations.

In this study, we examine the youngest Polish loess (L1LL1 = MIS 2, ca. 26–15 ka) for its suitability as a new, loess-focused reference dataset. Eighty-nine samples from seven sites were analyzed, using inductively coupled plasma spectrometry. The loess had assumedly been homogenized during transportation and/or sedimentary recycling (LaN/SmN = 3.34–4.06, median 3.78; Eu/Eu* = 0.46–0.66, median 0.55; GdN/YbN = 1.08–1.49, median 1.26), and weakly affected by pre- or post-depositional weathering (CIA = 53.64–69.12, median 57.69). The statistically significant differences between sites in elemental medians were mostly conditioned by variations in grain size and in the “fresh” to “re-deposited” sediment ratio. Nonetheless, the overall geochemical composition homogeneity provided a basis for the estimation of Polish Median Loess (PML) data, as determined for 41 chemical elements. When used, PML data highlight differences between loess regions in Europe, thereby providing a tool for cross-continental comparisons.