Sándor Gulyás

Woodland-Grassland ecotonal shifts in environmental mosaics: Lessons learnt from the environmental history of the carpathian basin (Central Europe) during the holocene and the last ice age based on investigation of paleobotanical and mollusk remains

A treeline is a boundary used for marking the edge of the habitat at which trees are capable of growing. In ecology an upper and lower treeline is generally highlighted (Odum 1979) with an additional transitional zone (ecotone) found between the referred boundary and the adjacent open vegetation areas. Temperature besides precipitation is the major factor that controls the growth and sustainment of trees in an area. Nevertheless, several local ecological factors including such parameters as soil type, local vegetation, snow cover, elevation, geomorphology, rainshadow, gravity-induced mass movement, lightning, volcanic eruptions, wildfires caused by meteorite impact or wind shear can alter or prevent the sustainment of an arboreal vegetation in an area locally or regionally.

Results of Radiocarbon Analysis of Upper Weichselian Loess Sequences from Hungary

Approximately 10% of Hungary is covered by dust sequences of the Quaternary period. Samples have been taken from more than 50 outcrops and boreholes during fieldwork in the past 20 yr. Some 81 bulk samples taken from 27 profiles of the Hungarian loess regions have been analyzed for radiocarbon. Based on the 14C results, loess layers that accumulated between 33,000 and 12,000 BP were selected for further investigation. The sedimentation rates of the 27 loess profiles suggest periods of slow and quick dust accumulation in the Carpathian Basin during the Upper Weichselian period. It seems to us that some soil development and intense weathering periods interrupted the loess development during the Upper Weichselian in Hungary. According to the 14C dates, the estimated average rate of sedimentation was 0.31 mm/yr in both the northern and southern parts of the Carpathian Basin between 33,000 and 12,000 BP.

New Radiocarbon Dates from the Late Neolithic Tell Settlement of Hódmezővásárhely-Gorzsa, SE Hungary

Understanding the internal chronology of the Late Neolithic Tisza culture and the Neolithic of the Tisza region is the subject of debate in both Hungarian and international prehistoric research. The layer sequence of the Late Neolithic Gorzsa tell from SE Hungary offers ideal match points for determining the successive phases of the Tisza culture. According to the results published so far, in the Gorzsa sequence the Tisza culture was divided into 4 main phases with a fifth phase representing the transitional period to the Early Copper Age. Excavations were carried out in 33 profiles covering about 2% of the original area of the entire settlement. The archaeostratigraphy established was based on the identification of microhorizons corresponding to settlement levels. Radiocarbon dates published thus far were created using a pool of various objects of differing microhorizons deriving from different profiles. However, as archaeological results revealed, the settlement was characterized by frequent, minor spatial shifts during its evolution into a tell complex. Here, we present a succession of 7 14C dates deriving from a single profile located at the northeastern flank of the excavation area. The 7 dates span the entire profile from the uppermost microhorizons down to the lowermost ones. The new dates were compared with the existing relative chronology mentioned above. According to our findings, material was deposited in this part of the site mainly during the first 2 phases of evolution of the tell complex. The later phases are either less developed or missing due to possibly a spatial shift of the center of the tell complex resulting first in a deceleration and finally a complete cessation of artifact accumulation to the northwest flanks of the former natural levee. Thus, the previous hypothesis of spatial shifts based on relative chronologies within the site has been corroborated. Furthermore, the congruence between our new dates corrected for any reservoir effect and the previous dates of Hertelendi (1998) may refer to a correct determination of freshwater shell carbonate reservoir effect in the fluvial system of the Tisza River, which may be used in further studies in the area.

Radiocarbon-Dated Paleoenvironmental Changes on a Lake and Peat Sediment Sequence from the Central Great Hungarian Plain (Central Europe) During the Last 25,000 Years

One of Hungary?s geological and environmental treasures is nestled in the heart of the Great Hungarian Plain. The catchment basin of Lake Kolon was subjected to detailed environmental historical studies starting in 2005. Undisturbed cores taken along transects of the basin were subjected to detailed sedimentological, paleoecological, and geochemical studies. To establish a reliable timeframe of the lacustrine and marshland sedimentary sequence identified, 22 samples were analyzed by accelerator mass spectrometry (AMS) in the radiocarbon laboratories of Poznan and Tucson. With the new results in hand, we had the opportunity to elucidate the geological evolution of the area for the past 25,000 yr. This sequence is highly beneficial, as it is probably the most well-dated profile of the Quaternary from the area studied. The new absolute dates enabled the comparison of local geological evolution of the studied area with those of global climatic changes. As seen from our findings, the geological evolution of the catchment basin was congruent with major climatic events during the Pleistocene and the entire Holocene. However, a very peculiar trajectory was identified for the terminal part of the Pleistocene and the opening of the Holocene regarding the evolution of the landscape, the vegetation, and the fauna of this part of the Great Hungarian Plain.

The Palaeogeography of Lake Pannon During Deposition of the Congeria rhomboidea Beds

Lake Pannon covered the area of the Pannonian Basin during the late Miocene. According to the seismic profiles, prograding deltas from the NW and NE resulted in the S-SE migration of the northern palaeoshoreline and the gradual aggradation of the lacustrine basin. The molluscan fauna living in the lake underwent a very rapid evolution. For the younger species, the possibilities of spreading became more and more restricted due to the gradual shoaling of the lake. The bivalve species Congeria rhomboidea M. HORNES occurs widely in the Upper Pannonian (Pontian sensu Stevanovic) deposits of Hungary and the neighbouring countries. Its evolution is relatively well understood. According to magnetostratigraphic data this species appeared in the lake 8.5 mya. According to the maximal geographical distributions of C. rhomboidea and its ancestor Congeria praerhomboidea STEVANOVIC occurring in sublittoral clay and silt along with the representatives of Prosodacnomya coming from littoral and lagoon deposits of the same age the estimated water coverage was around 75,000 km2 at the time of first emergence of C. rhomboidea in the lake. In the north the distribution of C. praerhomboidea is strictly restricted to the north of that of C. rhomboidea, its descendent, implying a clear S-SE trend in the migration of the lake’s northern palaeoshoreline. Distributions of the littoral Prosodacnomyas in relation to the sublittoral C. rhomboidea of the same age display a similar pattern. Meanwhile the western and southern palaeoshorelines underwent only minor fluctuations.

Holocene lacustrine carbonate formation: Old ideas in the light of new radiocarbon data from a single site in central Hungary

Lacustrine carbonate deposition in Hungary has been traditionally interpreted as the outcome of the dry, hot climate prevailing between 7500 and 5000 14C yr BP (hereafter BP) (~6400 and 3800 BC), triggering the partial desiccation of minor ponds and lakes. A comparative analysis of 5 14C results from the site of Cslyosplos, central Hungary, with those of other Hungarian lacustrine carbonates yielded stunning new results. According to these new dates, carbonate deposition must have initiated much earlier, possibly around 10,00011,000 BP (950011,000 BC) in the Carpathian Basin. Furthermore, the formation of lacustrine carbonates must have come to an end at very different times in different parts of the basin, contrasting previous views on the uniform and synchronous cessation of lacustrine carbonate formation in Hungary. According to the newest results presented here, carbonate deposition in the southern and southeastern parts of the basin ceased around 6000 BP (~4900 BC). Meanwhile, in the central parts, deposition continued as long as the terminal Bronze Age (~1300 BC).

Phytolith aided paleoenvironmental studies from the Dutch Neolithic

Abstract There is increasing evidence for crop cultivation at sites of the Neolithic Swifterbant culture from ca. 4300 B.C. onwards. Presence of cereal fields at the Swifterbant S2, S3 and S4 sites has been corroborated from micro morphological studies of soil samples. Swifterbant sites with evidence for cultivated plants are still scarce though and only emerging, and have produced very low numbers of charred cereals only. The major aim of our work was to elucidate the environmental background of the Dutch Neolithic site Swifterbant S4 based on the investigation of phytolith remains retrieved from soil samples. In addition to find evidence for crop cultivation independently from other studies. Samples were taken at 1 cm intervals vertically from the soil section at the central profile of site S4. Additional samples were taken from pocket-like structures and adjacent horizons above and below. Pig coprolites yielded an astonishing phytolith assemblage which was compared to that of the soil samples. A pig tooth also yielded evaluable material via detailed investigation using SEM. The evaluation of phytolith assemblages retrieved from the soil horizons plus those ending up in the droppings of pigs feasting in the area enabled to draw a relatively reliable environmental picture of the area. All these refer to the presence of a Neolithic horticulture (cereal cultivation) under balanced micro-climatic conditions as a result of the vicinity of the nearby floodplain. These findings corroborate those of previous soil micro-morphological studies.