LOESSFEST'09 | Aug. 31st – Sept. 3rd, 2009 |Novi Sad-Serbia
The Thickest and the Most Complete Loess Sequence in the Carpathian Basin: The Borehole Udvari-2A
Koloszár, L.1, Marsi, I.1
1Geological Institute of Hungary, 1143 Budapest, Stefánia út 14, Hungary
The key geological borehole Udvari-2A is located in Hungary at the Tolna Hegyhát hills, in the central part of the Carpathian basin. Its detailed interpretation yielded valuable information on the stratigraphy and the post-Pannonian continental sedimentation regime of this territory. Stratigraphic data provided by the borehole facilitated the drawing up of a more precise picture on the post-Pannonian paleoenvironment and history of the evolution of the area. The borehole cut a thick series of the post-Pannonian Tengelic formation and the overlying, presumably complete sequence of the continental loess sediments of this region. The magnetostratigraphic correlation indicates that the 97 m thick loess sequence in the borehole Udvari-2A is the thickest and most complete so far recorded in Hungary and the deposition of loess started approximately at 1.1 Ma. In this sequence each of the four separatable sedimentary periods of the loess are represented by distinct sediments. A theoretical stratigraphic column is also outlined to describe the Paks Loess Formation using data from the SE Transdanubia, defining and characterising its litological units. Since the formation is widely known, it was possible to correlate the most complete facies in SE Transdanubia with the marine oxygen isotope scale, and this opens up opportunities even for global correlation.
The presentation was supported by the TÉT foundation CRO-24/06 and OTKA K 75801.