Three climatic cycles recorded in a loess-palaeosol sequence at Semlac (Romania) – implications for dust accumulation in the Carpathian Basin and the northern Hemisphere

Abstract

Recent investigations of the Semlac loess section in the Southeastern Carpathian Basin, which is situated at the Mures River in its lower reaches (Banat region, western Romanian), are presented. Dating back to marine isotope stage (MIS) 10, the more than 10 m thick loess sequence includes four fossil sol-complexes developed in homogenous relatively fine silty loess. Because good preservation and sedimentation of fine silt Semlac is regarded as a key section for the Carpathian Basin, which offers possibilities to a) improve the understanding of the type and composition of the lowland loess sequences in the Carpathian Basin also beyond the last interglacial palaeosol complex, b) to reconstruct the temporal evolution of the local loess-palaeosol successions and c) to compare the loess of the region to loess-sequences in adjacent and dust proxy data in the northern hemisphere.
A strikingly sinusoidal course of physical property data with depth/time point to relatively homogenous, quasicontinuous background sedimentation of dust, interpreted as long-range transport (LRT). An integrated age model based on correlation to reference records and luminescence dating is compiled. Applying this age model we compare climate proxy data from Semlac to both global data and to data from the very southeast of the Carpathian Basin (Vojvodina, Serbia).
The obtained results provide new insight into the dust accumulation regime in the Carpathian Basin and offer new palaeoenvironmental information for the region and are an important step towards establishing a catena from the thin loess-like sediments of the Banat foothills in the East towards the thicker and seemingly more complete loess sections of the southeastern and central Carpathian Basin. Disentangling grain size data from soil formation proxies gives quantitative estimates for the contribution of original sediment and weathering (through soil formation) to the present clay fraction. Patterns of clay from direct sedimentation are dissimilar to grain size proxies from China, suggesting western and eastern Eurasian loess to have different mechanistic origins.

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Bibliography

Zeeden, C., Hambach, U., Kels, H., Schulte, P., Eckmeier, E., Marković, S., Klasen, N., Lehmkuhl, F. (2016): Three climatic cycles recorded in a loess-palaeosol sequence at Semlac (Romania) – implications for dust accumulation in the Carpathian Basin and the northern Hemisphere. EGU General Assembly 2016, 17.-22.4. 2016, Vienna, Austria