Applications in environmental and palaeoenvironmental studies

Gliwice Radiocarbon Database (GRDB). Radiocarbon method was started in Poland 50 years ago. The Gliwice Radiocarbon Laboratory was founded at the break of 60' and 70', developing from the very beginning collaboration with different centres of natural sciences and archaeology in Poland and abroad. The outcome of this collaboration consists of about 10 thousand assays of ages of samples dated for geology, geomorphology, stratigraphy, palaeogeography, archaeology, etc. Separate carbon isotopes investigations are conducted in geochemistry and in environmental sciences.
Initially results of dating were organised in thematic sets, suitably to the needs of publishing scientific works containing also interpretation of obtained dates. In course of time, as the number of available data was increasing and computer storage and processing became possible, an idea was proposed in mid 80' to create a computer database using commercial software product dBase. It coincided with new needs for statistical processing and analysing of large data sets, particularly calibrated radiocarbon dates. Possibility of widening access to previously published dating results rendered in the form of ready-to-use sets retrieved from the database, prompted the staff of the Gliwice Radiocarbon Laboratory to use modern information technologies to create a new database.
The project was formally formulated and submitted to the State Committee of Scientific Research (KBN) for funding (KBN Project "Radiocarbon dates database for needs of reconstructing of past changes in natural environment"; contract No 6 P04E 007 017). The project was realised in years 1999-2001 and now about 1000 of first radiocarbon assays is available publicly via internet.

Anthropogenic changes of the isotopic composition of atmospheric carbon in the Upper Silesia region. Radiocarbon measurements in tree-rings and CO₂ collected in NaOH solution in the Upper Silesia indicate a significant decrease in ¹⁴C concentration compared with "clean air" during the period of 1966-1992. The effect can be described by the parameter: 14S = ?2.3 ą 1.2%. This value is determined by two main processes: a systematic increase of fossil fuel combustion that increases amount of "dead" carbon dioxide, and nuclear weapon tests that are sources of additional ¹⁴C. The maximum increase was recorded in 1963, when the radiocarbon concentration in atmospheric carbon dioxide was more than doubled when compared to the atmosphere prior to tests.

Anthropogenic variations in the composition of the youngest sediments of Lake Gościąż
In this study, changes of chemical and mineralogical composition, diatom assemblages, sedimentation rate, and other sediment parameters during the last 330 years were interpreted in terms of human impact. History of human influence was known from written documents. It was shown, that the steps of lake eutrophication could not be described by a single parameter, but they did occur in form of subsequent abrupt changes of several parameters, the sequence lasting for 10-15 years. It was also shown that the strongest human influence on the lake biology and chemistry occurred rather through the animal husbandry than agricultural activity. Anthropogenic effects are inscribed in the time record of carbon isotopic composition (¹⁴C and ¹³C) and ¹³⁷Cs concentration after nuclear weapon tests and the Chernobyl accident.
Variation of isotopic composition of carbon in the karst environment. A comprehensive study of carbon isotopes in several karst springs and their environs in a contemporary karst environment in the region of Cracow Wieluń - Upland and Western Tatra Mts, Southern Poland, were made. Samples of water, plants and carbonate deposited on aquatic plants, were collected in 1992-1994 and ¹³C values and ¹⁴C concentrations measured. The youngest calcium carbonates from caves where deposition is still being observed or ceased no more than a few hundred years ago were also investigated. The determination of a ¹⁴C dilution factor in these carbonates provides a possibility of determining the "true" radiocarbon ages of old speleothems from caves in the area under study and the use of old speleothems as suitable material for extending the ¹⁴C calibration time scale; the "absolute" age having been determined by U/Th or AAR dating methods.

Calendar time-scale for reconstruction of environmental changes of the Late Glacial and Holocene. The sediments of Lake Gościąż are annually laminated, and using several cores a precise floating varve chronology (9662 ą 90 varves) of the lower section of sediments has been constructed. The varve chronology was used as a tool to determine the duration of the Younger Dryas cold period prior to the beginning of Holocene, and of the transitional periods of cooling and warming at the boundaries of YD. It has been shown that the climatic changes during the Younger Dryas in Europe were as abrupt as those observed in Greenland. The changes of varve thickness during the Late Glacial and the Holocene have been attributed to changes in vegetation around the lake as well as to the changes of biological productivity in the lake. Comparison of calendar (varve) age and ¹⁴C ages of bulk carbonate fraction of sediments was used to reconstruct the changes of lake-level during the last 13 000 years. The varve chronology of the upper part of sediments was used to date the phosphate-eutrophication of the lake in the Middle Ages.

Late Glacial and Holocene water level changes of the Gościąż Lake derived from carbon isotope studies. Comparison of measured ¹⁴C activities in carbonate fractions of lake marl with varve ages allowed for accurate estimation of secular changes of ¹⁴C dilution factor of total dissolved inorganic carbon. Basing on the geochemical model developed by Broecker and Walton it was possible to reconstruct mean lake level during the Late Glacial and Holocene. Obtained patterns of lake level fluctuations show remarkable similarities with behaviour of Swedish lakes and general agreement with available records from European lakes.

Radiocarbon chronology of the sediments from the Gościąż Lake basin and its surroundings. ¹⁴C dates obtained on peat layer underlying the oldest lacustrine sediments in Gościąż Lake and other lakes yielded consistent estimate of the beginning of organogenic sedimentation in this area to ca. 13 ka BP. Three periods of lacustrine gyttja sedimentation were distinguished in cores taken in the nearest surroundings of Lake Gościąż and adjacent lakes: 11.8-10.2, 8-7 and 2.7-2.1 ka BP. Basing on ¹⁴C dates of lithological boundaries in these cores the changes of lake level during the last 12 ka BP were reconstructed.

Environmental changes of the Late Glacial recorded in laminated sediments of Lake Perespilno, eastern Poland. The varve chronology of Lake Perespilno sediments covers 3100 years. The younger part of this chronology has been synchronised with sediments. The chemical and mineralogical composition, varve structures and magnetic susceptibility indicate strong environmental changes during the Younger Dryas, especially during the first 300 years of that period. These changes were connected not only with the cooling but also with the drop of lake and groundwater level, probably due to the drastic decrease in precipitation at that time.

Stable isotopes of Holocene calcareous tufa as paleoclimatic indicators. Results of measurements of δ¹⁸O and δ¹³C in tufa samples dated with ¹⁴C method are used to reconstruct Holocene climatic changes in southern Poland. The stable isotope composition was used to estimate mean annual temperatures in the interval 9500-2000 yr BP. When the resulting curve of temperature changes in southern Poland is compared with results of other methods of reconstruction of paleoclimate in central Europe, a reasonable agreement among the different specific methods is seen.

¹⁴C and TL studies of the karst pipe systems in Southwest England and South Wales. Paleokarst forms known as "pipes" were dated by ¹⁴C and TL methods. ¹⁴C ages were obtained from carbonate cements within sandrock and on the pipe walls. Statistical analysis of dates indicate that TL ages measured for quartz grains separated from sandrock samples are older than 80 ka BP whereas the corresponding TL dates obtained from the sandy material of pipe infills center around 40 ka BP. All carbonates yielded finite apparent ¹⁴C dates that range from 45 to 27 ka BP for sandrock and from 30 to 22 and 15 to 7 ka BP for pipes. On the base of geochemical consideration it was concluded that date ranges indicate warmer climate periods.

Paleoclimatic implications of ¹⁴C, U/Th and AAR dating of speleothems from Cracow-Wieluń Upland. Cracow-Wieluń Upland is the largest and best-explored karst region in Poland. On the base of statistical analysis of 125 dates the warm and cold climate periods were indicated during the last 50 000 years BP. Comparison of dates obtained by ¹⁴C, uranium-thorium (U/Th) and amino-acid recamisation AAR) methods was made. Changes of δ¹³C and δ¹⁸O in speleothems indicate that their growth between 30 and 20 ka BP may be interpreted as reflecting changes of paleoclimatic conditions.

Applications in archaeology

Analyses of calibrated radiocarbon dates for Andean archaeology. Some analyses of calibrated radiocarbon dates were made basing on the prepared database of the radiocarbon dates from Central Andes. The most important paper is intended to consider a problem of possibility of ¹⁴C method application to establish the Inca state chronology. Authors attempted to find out, using composite probability distribution of calibrated radiocarbon dates, the time intervals of Inca Imperial Phase and Inca Preimperial Phase and to make rough estimation of time intervals corresponding to periods, when succeeding rulers of The Inca Empire reign. Obtained results seems to confirm time intervals established basing on the chronicles.

Chronology of early Slavonic settlement and navigation at the mouth of Odra River. In frame of this research, a series of wooden fragments of Slavonic boats, found in archaeological excavations in Wolin, had been dated by the radiocarbon method. We could show that those boats were in use during several periods in the second half of the first millennium AD. The distinction of separate phases appeared much clearer in terms of calibrated than of conventional radiocarbon age.

Dendrochronological dating of oaks from the Odra River valley. Dendrochrology is the most accurate method of absolute age determination of tree trunks. The series of oak trunks from the paleochannels of Odra River in Roszków had been dated absolutely by this method, to the period of 411-734 AD. This dating was possible due to the correlation of series of tree-ring widths of studied oaks with those from the master tree-ring chronologies from southern Germany. This was the first match of tree-ring chronologies from Poland and Germany. The tree-ring width series from Roszków was later incorporated in the long tree-ring chronology of oaks from southern Poland.

Radiometric dating of excavations in Karlukovo karst area, Bulgaria. Excavations in Temnata Cave had led to the discovery of a long sequence of flint industries, extending back in time to the Middle Paleolithic. Even the sequence of Epigravettian and Gravettian occupation is the longest known in the Balkans and covers almost 20 000 years, from 13 000 to 30 000 BP. In order to establish absolute time scale sequence, several dating methods were applied. Bone and charcoal samples associated with Epigravettian and Gravettian occupation were used for ¹⁴C dating. Burnt flint representing older Gravettian and Aurignacian occupation were used for TL dating. The thermoluminescence (TL) and electron spin resonance (ESR) methods were applied to date some speleothems from the Temnata Cave.

Radiocarbon dating and dendrochronology of Neolithic and Lusatian culture settlements. Interdisciplinary analyses (radiocarbon, dendrochronological and archaeological dating) of material collected in excavations in Biskupin and Żuławka Mała, Great Poland, permitted to distinguish several phases of occupation from the Neolithic and Bronze periods. Radiocarbon studies of these Lusatian Culture fortified settlement (Bronze Age and Early Iron Age) in Biskupin have been started in 1981 and were continued since 1994 with participation of Gliwice and Gif-sur-Yvette radiocarbon laboratories. The results of conventional radiocarbon dating of series of wood and charcoal samples collected from archaeological trenches locate the Biskupin settlement between 850 and 400 cal BC. Dendrochronological studies gave the date of 747 BC for the building of the fortified settlement. This date is supported by wiggle matching technique. The material, identified in the course of excavations in Żuławka Mała and analysed using ¹⁴C and dendrochronological methods, enabled to distinguish eight occupation phases for Neolithic and Bronze Periods.

TL dating method in archaeology. TL dating method was successfully applied to a number of archaeological sites from the Palaeolithic period. Depending on the particular site either geological strata bearing archaeological findings or burnt flint artefacts were dated. The sites include several Central Europe sites (Zwoleń, Dzierżysław, Temnata Dupka) and North Africa sites (Wadi Kubbaniya, Bir Sahara, Bir Tarfawi). TL dates contributed to the wide range of investigations made by different methods and supported the chronology for these sites.

It is also worth to be mentioned that besides DOR's contribution to solving numerous geological, environmental and archaeological problems listed above, the scientific data obtained in the DOR became basis for many theses and dissertations in earth sciences and in archaeology.
The following two Figures C4.1 and C4.2 show the outcome of the DOR over the period 1961 to 2001 measured by the number of publications published by staff members in different categories and in different types of journals.

Figure C4. 1 Number of publications per year in different categories.

Figure C4. 2 Number of publications per year in journals with national circulation (Polish) and in journals with international circulation.

List of monographs, books, textbooks authored or co-authored by the DOR staff members.
Full list of publications published by the DOR staff members.