Naslov
Comparison of recent and Pleistocene climate-isotope data from malakofauna

Autori
Banak, Adriano ; Ferić, Pavle

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Knjiga sažetaka = Abstracts Book / Horvat, Marija - Zagreb, 2010, 357-357

Skup
4. Hrvatski geološki kongres s međunarodnim sudjelovanjem = 4th Croatian Geological Congress with international participation

Mjesto i datum
Šibenik, Hrvatska, 14.10.2010. - 15.10.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Baranja ; Bansko brdo ; Pleistocene ; recent, loess ; malakofauna ; stable isotopes

Sažetak
Baranja is region in eastern part of Croatia. It is bounded from east and south, by rivers Dunav and Drava and by Hungary from the north/north- west. Baranja is mostly covered by Pleistocene sediments, with some local outrocps of Miocene sediments. Pleistocene sediments are dominantly loess, loess-like sediments ('marsh' loess), fluvial, aluvial and marsh sediments, covering Baranja plains. Only high ground in Baranja is Bansko brdo hill (241m), situated in northern part of region, stretching in south-west to north- east direction, about 20 km. Geological basement of Bansko brdo hill is made of limestones, marl, sandstones with conglomerats, andezite, riolte, andezite breccias and tuff’s, which are all Miocene age (JENKO, 1957–1959). Igneous rocks are determined to be Badenian age (PAMI] & PIKIJA, 1987). Bansko brdo is covered with loess. Total estimated thicknes of loess in investigated area is aprox. 30 m. Oldest loess sections at Bansko brdo, at Zmajevac profile is 121 ka (GALOVI], 2009), which is base of upper Pleistocene. Loess is eolian silt (SMALLEY, 1966b ; SMALLEY et al., 2001). It was deposited by strong winds (dominantly northern) on big open tundras and steps, during Pleistocene. Loess is abundand with fossils, especially malakofaunal (fossil gastropods). 30 bulk samples of loees were taken from loess sections and more than 5000 shells of gastropods were obtained. They can be used for reconstructing paleoclimate and environment, because variations in malakofaunal assemblage, are evidence for climate changes. Stable isotope results are more accurate, they provide quantified values for temperature and humidity changes. Gastropod shells from 3 most abundand fossil species (Helicopsis hungarica WAGNER Chondrula tridens MULLER and Arianta arbustorum LINNAEUS) were analysed on stable isotopes ÄO18 and ÄC13 in IAMC-CNR in Naples. Isotope results from loess sections, suggest a slight arid/humid and cold/warm variations in climate, during upper Pleistocene. These variations reflect stadial/interstadial climate changes in upper Pleistocene. Stable isotope data can’t provide absolute numbers, just relative differences of Pleistocene and recent temperature/humidity. Due to that problem, shells of recent gastropods, collected from meadows, fields and loess sections were also analysed (ÄO18 and ÄC13). Numbers obtained from stable isotope results are matched with data of average annual temperature and humidity, at Bansko brdo for year 2009. (Beli Manastir meteorological station). These matched and calculated results, provide a certain 'standard', which can be used to determin (with caution) absolute temperature/humidity during upper Pleistocene. Results from recent gastropod shells and fossil gastropod shells, indicate significant difference in recent and Pleistocene climate (for Baranja region, which can be aplied for southeast Europe). In general, in upper Pleistocene, climate was much more colder, then recent, and also more arid. In some periods (interstadials) climate was more alike recent climate, but main trend was cold and arid climate, with average annual temperatures more than 7 °C lower than today. These conclusions are expected, but they are quantified and based on data from analytical method (that is very accurate), rather on assumption that climate in upper Pleistocene is alike to recent climate in periglacial environments.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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