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Tufa deposits from four separate occurrences in the Dinaric Karst of Croatia were characterized with respect to mineralogy, geochemistry and activity of radionuclides. Three of the specimens are of Holocene age, formed during Atlantic, Subboreal and present climate. Two locations (Plitvice Lakes and Krka River) have previously been studied. Two locations (Mrenica and Slunjčica rivers) have not attracted scientific research yet. The major mineral in tufa is calcite. Minor minerals are quartz and dolomite, depending on location. Geochemistry of selected stream sediments (f <63 mm) from the Dinaric Karst was presented for comparison with tufa. Provided statistically significant number of samples studied, the ratios 238 U/ 226 Ra, 238 U/ 232 Th and 137 Cs may provide tighter constraints on the paleoenvironment. It is suggested to be used in comparison of different world tufas. In general terms it is discussed a hypothesis that relates the occurrence of tufas to atmospheric pCO 2 and climate conditions. In addition, the needs for future multidisciplinary research on tufa formation are discussed, because there are several other important parameters dependent on climate, which still have to be studied.

-This research compared the transfer of 137 Cs, 40 K, Ca, Fe, Rb, Sr, Cu, Zn, Pb, Ni, Mn and Cr from soil into honey derived from meadow flora, mixtures of floral and honeydew honey, and honeydew honey from fir and spruce forests in Gorski Kotar, Croatia. Radionuclides were measured by gamma-ray spectrometry, while other element concentrations were measured by X-ray fluorescence (XRF). Transfer factors (T f ) from soils into the studied honey types, expressed as a percentage, are defined as the ratio between element concentration in honey and in soil multiplied by 100. No significant differences were found, at P < 0.05, for all studied element concentrations for honeydew honey and mixed honey, in relation to the respective soil types from which honeys were collected. Concentrations of all studied cations were, at P < 0.05, significantly higher in honeydew honey compared to either mixed honey or floral honey. Honeydew honey could be used as a pollution indicator of 137 Cs, Cu, Rb, Cr and possibly Ni. © Inra/DIB/AGIB/Elsevier, Paris radionuclides / trace elements / soil / honey / transfer / biological indicator

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