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2 2002

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Radiocarbon time scale for deposition of holocene calcareous tufa from Poland and India (Orissa)

Pazdur A., Dobrowolski R., Durakiewicz T., Mohanti M., Piotrowska N., Das S.

Geochronometria

2002

Vol. 21

85-96

14 C concentration measurements together with carbon and oxygen stable isotope analysis in calcareous tufa give possibilities for reconstruction of time scale and palaeoclimatic conditions of sedimentary processes. Results of isotope examinations of 2 profiles with organic and tufa sediments from Eastern Poland and 8 calcareous tufa sites from Eastern India (Orissa) are given. A systematic error of 14 C conventional age of carbonate fraction of tufa samples as reservoir age (T R ) was estimated. The T R values of different type of tufa sediment are determined by stream water energy. On the basis of known experimental dependence between T R and delta 13 C for tufas deposited in high, average and low energy water, unknown values of T R and corrected 14 C ages (T CCA ) were calculated for samples from India tufa sites. Continuous deposition of organic and carbonate sediments in Polish profiles give the possibility to calculate the approximated T CCA ages on the basis of dependence between T CCA and a sample depth in a profile, and time scale reconstruction of delta 13 C and delta 18 O changes in carbonate fraction of tufa samples during the whole Holocene.

Delta 13C and delta 18O time record and palaeoclimatic implications of the holocene calcareous tufa from south-eastern Poland and eastern India (Orissa)

Pazdur A., Dobrowolski R., Durakiewicz T., Piotrowska N., Mohanti M., Das S.

Geochronometria

2002

Vol. 21

97-108

Measurements of delta 18 O and delta 13 C in tufa samples dated by 14 C method have been used to reconstruct climatic changes in Southern and Eastern Poland and in Eastern India (Orissa) for the last ca 13,500 years. Stable isotope time record delta 18 O in calcareous tufa profiles can be interpreted as palaeoclimatic record if dependence between oxygen isotope composition and temperature for the specific climatic region is known. Estimated sedimentation temperatures of calcareous tufas from Polish sites indicate the mean year of air temperatures during the last 12,000 years and mean winter and summer temperature for Orissa state, using stable isotope analysis for calcareous tufa from Indian sites. The estimated temperatures have real values, comparable with contemporaneous sedimentation temperature. The characteristic trend of the temperature changes increasing for Poland and decreasing for Orissa, since the beginning of the Holocene till today, can be observed with climatic optimum ca 5000-6000 BP synchronous in both countries.