Madaras László – Szabó László – Tálas László szerk.: Tisicum - A Jász-Nagykun-Szolnok Megyei Múzeumok Évkönyve 8. (1993)
Sümegi Pál: A jászfelsőszentgyörgyi szunyogos felső-paleolit telephely üledékföldtani és sztratigráfiai elemzése
PÁL SÜMEGI SEDIMENTARY GEOLOGICAL AND STRATIGRAPHICAL ANALYSIS MADE ON THE MATERIAL OF THE UPPER PALEOLITHIC SETTLEMENT ATJÁSZFELSŐSZENTGYÖRGY-SZÚNYOGOS Introduction In the autumn if 1990 Viola Dobosi excavated an Upper Paleolithic settlement in the site called Szunyogos II. belonging to the village Jászfelsőszentgyörgy. The site is on the alluvial fan of the Ancient Zagyva, in the socalled Hatvan plain (Marosi S. - Somogyi S. 1990). The Upper Paleolithic settlement was found on a sand dune at a height of 110,9 m above sea-level. The author of the present article has joined the team of excavators to make sedimentological, sedimentary geological and geomorphological analyses on the material of the settlement. The aim of his investigations was to get informations on the sedimentary environment of the Upper Paleolithic site, to clear up paleogeographic conditions and to determine the lithostratigraphic position of the sequence. Since only very few works have been published so far on the Pleistocene and Holocene paleogeographic conditions and geological evolutionary history of the Jászság and neighbouring areas (Balla Gy. 1958, Fodor F. 1942), similarly, in other publications it is only touched upon (Borsy Z. 1987, Rónai A. 1972. 1985), in the initial phase of our activity we made a detailed and comprehensive collecting and surveying in the field. These activities resulted in several new paleogeographic, paleontological and sedimentary geological data used for to write this paper, however, unpublished so far (Sümegi P. 1991). Results of investigations We investigated at several points the profile of the W-E direction wall of the trial trench which revealed the settlement (Fig.2.), and at a certain point we made a detailed granulometric analysis (Fig. 3.). This analysis was completed by the determination of the carbonate content, 13 C and 18 0 isotope analyses and also by sediment statistical investigations (Fig.3.). Granulometric composition was determined by elutriation, while carbonate content was determined with the aid of calcimeter. Sediment-petrological parameters were calculated by using the Fold-Ward formula (Folk, R.L. - Ward, W.C. 1957, Inman, D.L. 1952). Isotope measuration was made by Ede Hertelendi, researcher of the ATOMKI, using the method published in 1986 (Hertelendi et al. 1986). To make a more exact distinction between sediment facies we made also scanning microscope investigations on quartz grains. KrinsleyDoornkamp chemical treatment was used to prepare samples (Krinsley, D.H. - Doornkamp, J.C. 1973). Scanning microscope investigations were completed by tradíciónál grain shape investigations (Miháltz I. - Ungar Т. 1954, Molnár B. 1961, Cailleux, A. 1952). The results of microscopemorphological investigations made on sand grains were compared to the results of similar analyses made on samples originated from other sandy regions of Hungary (Borsy Z. et. al. 1982, Molnár B. et al. 1988). Paleogeographic conditions in the environment of the site The archeological site is situated on the top of a sand dune, on the NNW side of it. The borehole at the base of the dune revealed a fluvial sequence (Fig. 1.), demonstrating that the underlying bed of surface eolian formations is fluvial material. This fluvial material is considered to be the material of an alluvial fan of Late Pleistocene age (Balla Gy. 1958). The paleontological and sedimentological investigation (Sümegi P. 1991) of a cross-bedded 63
