Wyniki wyszukiwania - Biblioteka Nauki

1

Radiocarbon age of late pleistocene glacigenic sediments in jonionys section of Merkine (Eemian) interglacial

100%

Gaigalas A. , Pazdur A. , Pawlyta J.

Geochronometria

|

2001

|

tom Vol. 20

75-80

EN

The stratotype of Merkine (Eemian) interglacial in Lithuania is the Jonionys section near Merkine town in south Lithuania. The lacustrine sediments containing rich fossil flora in this section were formed under the conditions of Merkine interglacial and Nemunas (Vistulian) glacial. The fossil-bearing Merkine deposits are overlain by a probably complete sequence of Early Nemunas and partly of Middle Nemunas deposits. Rewashed till-covered organic sediments were found in the upper part of Jonionys section. The exact age of glacial sediments of this section has remained largely unknown. Peat with wood remnants under the rewashed till have been investigated in Gliwice Radiocarbon Laboratory (Gd-10825: 31,500+2300/-1800 BP and Gd-14000: >31,000 BP). Its deposition probably took place just before the maximum of the last glaciation. In Jonionys section the Merkine interglacial, Early and Middle Nemunas nonglacial sediments were probably accumulated in the time of climatic fluctuations, but without glacigenic sedimentation. The glacigenic sediments in the upper part of Jonionys stratotype section are younger than 30,000 BP and belong to the Late Nemunas glacial maximum. Recent radiocarbon dating are important for the establishment of the standard area of the European Würm (Vistulian, Valdaian, Poozerian and Nemunas) glacial.

2

Precision of 14C dating in Gliwice Radiocarbon Laboratory. FIRI programme

100%

Pazdur A. , Fogtman M. , Michczyński A. , Pawlyta J.

|

tom Vol. 22

27-40

EN

In this paper the precision and accuracy of radiocarbon dating in Gliwice Radiocarbon Laboratory on the background of intercomparision programs is discussed. Here are briefly presented results of individual comparisons between laboratories from eight countries and three international intercomparison programmes: ISC Programme (1986), TIRI Programme (1994) and FIRI Programme (1999). Moreover the short description of Gliwice Radiocarbon Laboratory is presented. The main stress is laid on the description of FIRI Programme – types of samples included in Programme and methods of calculation of consensus values, but first of all the participation of our Laboratory in the programme is presented: pretreatment procedures of samples, results obtained in Gliwice and statistical analysis of these results. The most important conclusion, which may be drawn from this paper, is that Gliwice Radiocarbon Laboratory dating results are not biased by systematic error.

3

Measurements of tritium radioactivity in surface water on the Upper Silesia region

100%

Sawodni A. , Pazdur A. , Pawlyta J.

Geochronometria

|

2000

|

tom Vol. 18

23-28

EN

Tritium is produced naturally in the upper atmosphere by cosmic radiation. Oxygen atoms combine with the radioactive hydrogen atoms (tritium) to form radioactive water molecules, which reach the Earth in rain. This radioactive water seeps into groundwater, where the tritium decays with time. By measuring the concentration of radioactive tritium in a groundwater sample, geologists can approximate the age of water and pinpoint where the water recharges (replenishes) and discharges (exits) from an aquifer. Geologists can estimate groundwater flow rate and direction, and determine whether water from a shallow aquifer has a ready pathway to a deeper aquifer or not. The possibility of measuring the level of tritium radioactivity gave a chance to use tritium as a natural tracer in the water systems. The measurements of tritium radioactivity in groundwater are becoming important. Especially nowadays when tritium levels in precipitation have returned to pre-bomb values (4-25 TU) and the technogenic emissions of tritium are becoming more significant, and may affect its natural patterns on a local or regional scale. This article presents the results obtained in 1998 by measuring tritium radioactivity in surface-water and precipitation. All analyzed samples were taken during 1995-1996, from the Upper Silesia area. The obtained results confirmed, that tritium concentration has returned to the pre-bomb values.

4

Comparison of the radiocarbon dating methods used in the Gliwice Radiocarbon Laboratory

100%

Pazdur A. , Michczyński A. , Pawlyta J. , Spahiu P.

Geochronometria

|

2000

|

tom Vol. 18

9-14

EN

In the Gliwice Radiocarbon Laboratory the technique of gas proportional counters (GPC) filled with CO2 has been used since the beginning of the 70ties. In 1994 the Gliwice Radiocarbon Laboratory started the operation of a liquid scintillation spectrometry system (LSC technique) which consists of a Quantulus 1220 spectrometer and two vacuum rigs for benzene production. The work on the calibration of the Quantulus 1220 for the purpose of radiocarbon dating in three different geometries was undertaken. This paper presents characteristic parameters (background and standard counting rates) of facilities working on the basis of the methods above (GPC and LSC), and a comparison of results of radiocarbon dating obtained using other GPC and LSC facilities. Assessment of the analytical accuracy and precision achieved in routine liquid scintillation counting was based on the results of 14C measurements for TIRI intercalibration samples (and other samples), and on the comparison with the results obtained with well established gas proportional counting method performed in the Gliwice Laboratory.

5

The human bone oxygen isotope ratio changes with aging

100%

Stepańczak B. , Szostek K. , Pawlyta J.

Geochronometria

|

2014

|

tom Vol. 41, no. 2

147--159

EN

The oxygen isotope ratio (δ18O) in tissues is the outcome of both climatic and geographical factors in a given individual’s place of abode, as well as the physiology and metabolism of his organism. During an individual’s life, various rates and intensities of physiological and metabolic processes are observable in the organism, also within the bone tissue. The aim of this study is to verify whether involutional changes occurring as a result of the organism’s ageing have a significant impact on δ18O determined in the bone tissue. The material used for analysis was fragments of the long bones taken from 65 people, (11 children and 54 adults), whose remains had been uncovered at the early mediaeval (X–XI century) cemetery located at the Main Market Square in Kraków (Poland). The correlation analysis between δ18O of bone tissue and an individual’s age shows that up to 40 years of age, such a relationship does not exist in both, males and females. However, the conducted correlation analysis prompted the observation that after 40 years of life, δ18O in bone tissue significantly drops as females increase in age. Results suggest that the δ18O in bone tissue among older people may be the outcome not only of environmental factors but also involutional changes in bone linked to an organism’s ageing. Therefore, the interpretation of δ18O results relating to the description of the origin and migrations of older individuals should be treated with caution.

6

Stable isotopes as record of climatic changes of Daniglacial in Lithuania

88%

Gaigalas A. , Pazdur A. , Hałas S. , Pawlyta J. , Kazakauskas V.

Geochronometria

|

2001

|

tom Vol. 20

81-86

EN

Development of glaciolacustrine basins and varved clay sedimentation in Lithuania are closely connected with the course of ice retreat during Daniglacial time from 16,000 till 13,000 BP. Isotopic composition (delta 13C and delta 18O) of chemogenic carbonaceous samples from glaciolacustrine varved clays, which spread near glacier edge of South-Lithuanian (Balbieriýkis section), Middle-Lithuanian (Girininkai section) and North-Lithuanian (Joniškelis section) Phases of the Baltija (Pomeranian) Stage of Nemunas (Vistulian) Glaciation, has been studied. The obtained stable isotope data well confirm climatic changes of Daniglacial time in Lithuania. The gradual warming of climate is connected with the South-Lithuanian to Middle-Lithuanian and the Middle-Lithuanian to North-Lithuanian Interphasials as well as with the South Lithuanian interoscillations. The Interphasial lacustrine sedimentation with rhythmical lamination of carbonaceous sediments was observed in the middle part of the Balbieriýkis section (at a depth of 3.1-5.9 m). The following climatic changes of Daniglacial time in Lithuania are distinguished: (1) stadial (3000-6000), (2) glaciophasial (500-1000), (3) glaciooscillation (500-1000) years and (1) interstadial (1000-2000), (2) interphasial (250-450), (3) glacio-interoscillation (20-40) years. Regular succession of Daniglacial climatic and sedimentation changes in the local periglacial glaciolacustrine lakes, conditioned by recession of the last Scandinavian ice sheet, was revealed in the glaciolacustrine-lacustrine sediments for the first time.

7

Climate change and human impact in the southern Baltic during the last millennium reconstructed from an ombrotrophic bog archive

75%

Lamentowicz M. , Gałka M. , Pawlyta J. , Lamentowicz Ł. , Goslar T. , Miotk-Szpiganowicz G.

|

tom Vol. 28

3-16

EN

We present the last millennium of history of a peatland located in northern Poland. Our results are based on two replicate monoliths taken from a Baltic raised bog. We applied a high-resolution approach and radiocarbon dating to the peat material to obtain a detailed palaeoenvironmental reconstruction. To reconstruct past peatland moisture, we used three proxies: testate amoebae, plant macrofossils and pollen. Despite different peat accumulation and extensive hiatus in the formerly studied core, both monoliths show a similar pattern of changes. However, the core from this study provides us with more detailed data on S. fuscum disappearance which correlates well with the data from the other Baltic bog, Słowińskie Błoto. Our research shows that pristine Baltic bogs can be dated to AD 1350. Słowińskie Błoto palaeohydrology confirms AD 1300 as the beginning of the hydrological disturbance. In the case of the Stążki and Słowińskie Błoto bogs, the Little Ice Age (LIA) is recorded between AD 1500 and AD 1800. However, this climatic change might have been blurred by human impact. In the case of the Baltic bogs, their reference virgin state can be dated to AD 1200. After this date, we observed increasing human impact and climatic instability connected with the LIA. However, between AD 1800 and 1900, bogs were wet, most possibly due to climatic forcing. This fact suggests that despite human impact, recent peat deposits can still reflect climate. Our research provided information related to the time of existence, location and characteristics of the natural/pristine state. High-resolution peatland palaeoecology is crucial for restoration activities, e.g., rewetting and environmental management. The palaeohydrological context (supported by other proxtes) of the last 1000 years provides a retiable answer to the question: 'To rewet or not to rewet?'

8

Peculiarities of sedimentation conditions in the oxbow lakes of Dubysa River (Lithuania)

63%

Gaigalas A. , Pazdur A. , Michczynski D. , Pawlyta J. , Kleišmantas A. , Melešyte M. , Rudnickaite E. , Kazakauskas V. , Vainorius J.

Geochronometria

|

2013

|

tom Vol. 40, no. 1

22-32

EN

Abundant wood remains and buried trees have been found in the western part of Lithuania near Zakeliškiai and Lyduv?nai on Dubysa River (a tributary of Nemunas River) where deposits are rich in organic remnants and buried soils. In Zakeliškiai and Skiručiai sections of Dubysa River ox-bow sediments were investigated by various methods (dendrochronological, carbonate, granulometric, pollen and mollusc fauna analysis). In addition, these sections were dated using the radiocarbon method. Samples were collected from deposits of Dubysa River outcrops. The studied oxbow lakes have existed for more than 5 thousand years (from ca. 4300 BC to 1000 AD). During this period or-ganic rich deposits with trees and branches were formed in the oxbow lake. This indicates that at the end of Atlantic, during Subboreal and in the early Subatlantic periods there was a forest growing that contained mainly oaks which were falling down into an oxbow lake and later were covered by sandy and silty deposits. The granulometry of alluvial deposits, as well as the mixture of medium-grained sand and silt show different stages of Dubysa River palaeochannel formation: riverbed and oxbow lakes. Three climate warming cycles were revealed according to carbonate analysis data in all investi-gated sections. The rheophile thermophilous Holocene age molluscs species Bithynia tentaculata L., Unio cf. crassus Philipsson, Pisidium amnicum (Müller), Theodoxus fluviatilis (Linnaeus) have been found. The pollen composition and sequences have been divided into five local pollen assemblage zones (LPAZ) and described according to pollen spectra in each zone. In this way it is possible restore palaeoclimatic coherent evolution, trends and cyclical change.

9

Isotopic investigations of uppermost sediments from Lake Wigry (NE Poland) and its environment

63%

Pawlyta J. , Pazdur A. , Piotrowska N. , Poręba G. , Sikorski J. , Szczepanek M. , Król K. , Rutkowski J. , Hałas S.

Geochronometria

|

2004

|

tom Vol. 23

71-78

EN

This paper presents the results of the first isotopic investigations of sediments recovered from Lake Wigry (NE-Poland). In the spring/summer 2002 few sediment cores, plant samples and water profiles were collected specially for isotopic investigations. We obtained 210Pb activity profiles, 137Cs activity profiles and 14C activity/age profiles. Apparent ages of carbonate fraction for all sediment cores were determined. Sedimentation rates for collected cores were estimated using 14C dating method. In addition oxygen isotopic ratios of the water profiles, carbon stable isotopes ratio of collected sediment cores were determined.

10

Diagenetic signals from ancient human remains - bioarchaeological applications

51%

Szostek K. , Stepańczak B. , Szczepanek A. , Kępa M. , Głąb H. , Jarosz P. , Włodarczak P. , Tunia K. , Pawlyta J. , Paluszkiewicz C. , Tylko G.

Mineralogia

|

2011

|

tom Vol. 42, iss. 2/3

93--112

EN

This preliminary study examines the potential effects of diagenetic processes on the oxygen-isotope ratios of bone and tooth phosphate (δ18O) from skeletal material of individuals representing the Corded Ware Culture (2500–2400 BC) discovered in Malżyce (Southern Poland). Intra-individual variability of Ca/P, CI, C/P, collagen content (%) and oxygen isotopes was observed through analysis of enamel, dentin and postcranial bones. Using a variety of analytical techniques, it was found that, despite the lack of differences in soil acidity, not all the parts of a skeleton on a given site had been equally exposed to diagenetic post mortem changes. In a few cases, qualitative changes in the FTIR spectrum of analysed bones were observed. The data suggest that apart from quantitative analyses, i.e., the calculation of Ca/P, CI, C/P and collagen content, qualitative analyses such as examination of the absorbance line are recommended. The degree to which a sample is, contaminated on the basis of any additional, non-biogenic peaks, deemed to be contaminated should also be specified.