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The age of the subfossil trunk horizon in deposits of the Warta river valley (central Poland) based on 14C dating

100%

Dzieduszyńska D. , Peterga-Zganiacz J. , Krąpiec M.

Geochronometria

2011

tom Vol. 38, no. 4

334-340

The present study focuses on investigations carried out in the Late Vistulian succession of the Warta River deposits (central Poland) in which a horizon of subfossil trees was excavated. Preliminary conclusions on time record and past environmental conditions of a forest existence determined from radiocarbon dating, pollen analyses and geological evidence appear promising with view of treering chronologies.

Optical dating and sedimentary record from the terrace depositional profile of the Warta River (Central Poland)

75%

Dzieduszyńska D. , Petera-Zganiacz J. , Twardy J. , Kittel P. , Moska P. , Adamiec G.

Geochronometria

2014

tom Vol. 41, no. 4

361--368

Results of OSL dating and sedimentary studies from the profile of the low alluvial terrace of the middle Warta River are presented. The samples were dated using the single-aliquot regenera-tive method. Dating was used to establish a timing of the Weichselian Late Glacial events in the river valley environment. Stable conditions on the floodplain are expressed by the deposition of organic-rich series radiocarbon dated at 12 900-12 600 cal BP and 11 600-10 770 cal BP. Samples for OSL dating were collected from the mineral material deposited during the intensification of flood events during the Weichselian decline. The results obtained for the alluvia range from 12.78 ± 0.62 ka b2k to 14.33 ± 0.74 ka b2k. Sedimentological criteria allowed to distinguish between particular flood events. Overestimation of OSL ages is probably a result of rapidity of environmental changes in that time.

Properties and dimensional stability of 12 500-year-old subfossil pine wood

75%

Fejer M. , Zborowska M. , Adamek O. , Dzieduszyńska D. , Kittel P. , Petera-Zganiacz J. , Twardy J.

Drewno : prace naukowe, doniesienia, komunikaty

2014

tom vol. 57, nr 193

81--95

At the Koźmin Las site, in Central Poland, in the middle section of the Warta River valley, a series of well-preserved tree trunks and in situ stumps, as well as organic deposits, have been found. The tree remains are dated back to the period between 13,000–12,600 cal BP, i.e. to the Alleröd/Younger Dryas transition. The forest consisted predominantly of pines (Pinus sylvestris L.) of a maximum age of approx. 140 years and an average age of 68 years, and the river valley floor was overgrown. The forest was destroyed ca. 12,600 cal BP by deteriorating hydrological conditions or a sudden catastrophic event. The aim of the study was to assess the degree of degradation in terms of selected macroscopic, physical and chemical properties of a subfossil pine log. On this basis, a conservation process was developed, using aqueous solutions of polyethylene glycols (PEG) with varying concentrations of low- and high-molecular polymers. Treated and dried samples were compared in terms of their tangential and radial dimensional stability, as well as their hygroscopic properties.