Application of an Ion-Selective Electrode Method to the Determination of Chloride in 41 International Geochemical Reference Materials

Determinations of trace amounts (with one exception) of chloride are reported for 41 international geochemical reference standards, 12 of which have no previously reported literature values. All determinations were made by the chloride-specific ion-selective electrode method of Aruscavage and Campbell with certain refinements. Chlorine is separated from most other elements in geologic materials by acid-dissolution in a gas diffusion cell, and is subsequently determined as the chloride ion in basic solution. A statistical F-test was applied to 19 of the standards for which three bottles of each were analyzed in triplicate with no failures. All these standards, plus the other 22 for which six analyses were performed on a single bottle, exhibited a relative standard deviation of 1-6% for concentrations of chloride >50 ppm. For most samples chloride values agree well both with available, reported experimental values and with recommended or consensus values.     

Palaeopedological marker horizons in northern central Europe: characteristics of Lateglacial Usselo and Finow soils

Lateglacial buried soil horizons, which occur widely in sandy aeolian sequences of northern central Europe, were analysed in order to evaluate their regional pedostratigraphical and palaeoenvironmental potential. Data on stratigraphy, sedimentology, pedology, geochronology and palaeobotany from 29 palaeosol-bearing profiles at terrestrial sites are presented. Greyish Ahb and Eb horizons occur, as well as brownish Bwb and BwAhb horizons. They are 5–30 cm thick, showing similar pedological properties except colour, and they frequently bear charcoal typically from pine. Soil classification results in Albic Arenosols (Dystric) and Brunic Arenosols (Dystric) representing palaeosols of the Usselo and Finow types, respectively. Radiocarbon dating of the palaeosols reveals a dominance of Allerød ages followed by Younger Dryas and Preboreal ages. Most luminescence ages on overlying aeolian sands date into the Allerød–Younger Dryas interval. Mapping of all Usselo and Finow soil occurrences ( n =96) in northern central Europe known so far reveals a nearly closed Finow soil province between Usselo soil areas in NW Germany and central Poland, mainly situated in NE Germany. Most Usselo soils compiled contain charcoal, indicating widespread and repeated fires. Recent claims that the Usselo soil represents an event layer from rapid aeolian sedimentation caused by an extraterrestrial impact is rejected. Instead, both Usselo and Finow soils can be assumed to be pedostratigraphical marker horizons in northern central Europe and beyond.