Aeolian dust deposits in Hungary - a general description

Wind-blown loess and loess-like deposits are widely distributed in the Carpathian Basin, covering more than half of the area. Traditionally, based on its lithology, five main units have been distinguished; the Dunaújváros–Tápiósüly series and the Mende–Basaharc series belong to the young loess sediments, the Paks I. and Paks II. series belong to the old loess sediments, while the oldest strata of the sequence is part of the Dunaföldvár series. This last section consists of thin loess horizons between red (Mediterranean-type) palaeosols, reddish clays and loess-like deposits, underlain by red clay.

The upper three series can be correlated well with marine isotope stages (Gábris, 2007), and also with the Malan, Upper Lishi and partially with the Lower Lishi series in the Chinese Loess Plateau. The correlation with regional sequences, e.g. Serbian loess deposits (Markovic, S.B. et al., 2006, 2009), according to the stratigraphic similarities is also possible. These sediments can be regarded as the typical, glacial–interglacial loess–palaeosol successions.
The older loess and loessial section in the Carpathian Basin is known only from some exposures and boreholes. The lithological properties (reddish-yellow colour, massive structure, smaller thickness of loess layers between red palaeosols, large carbonate concretions) of these strata are very similar to the oldest sequences in Central Asia and to the Wucheng loess in East Asia.

The loess–palaeosol sections are generally underlain by red clay, which aeolian origin in Hungary according to the new data (Kovács, 2008; Kovács et al., 2008) is suggested. Thus, red clay can be considered as mature, accretionary palaeosol-complex/pedocomplex.

Red clay deposits under loess (Photo: Kovács, J.)

The red clay–loess–palaeosol record in the Chinese Loess Plateau indicates that the dust deposition started ~8 Ma in the area. Dust record of the ODP 885/885 site (North Pacific Ocean) show strong similarity in terms of their mean linear sedimentation rate pattern, indicating a period of increasing dust production in the inner part of the Asian continent (Rea and Hovan, 1995; Rea et al., 1998). Whereas, during the warm–moist Pliocene climate, the extent of the source area and the dust accumulation-rate were smaller, while the postdepositional pedogenic processes were stronger as compared to the Pleistocene conditions. The shift from this moist and warm climate to a more arid one allowed of the formation of the oldest loess deposits around 2.6 Ma.

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