0000000000599927
AUTHOR
Joachim Krause
Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 2: Alkaline earth elements as tracers of watershed hydrochemistry and provenance
Abstract. For reconstructing environmental change in terrestrial realms the geochemistry of fossil bioapatite in bones and teeth is among the most promising applications. This study demonstrates that alkaline earth elements in enamel of Hippopotamids, in particular Ba and Sr are tracers for water provenance and hydrochemistry. The studied specimens are molar teeth from Hippopotamids found in modern and fossil lacustrine settings of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by ca. two orders of magnitude for Ba (120–9336 μg g−1) as well as for Sr (9–21…
Chemical composition of modern and fossil Hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 1: Major and minor element variation
Bioapatite in mammalian teeth is readily preserved in continental sediments and represents a very important archive for reconstructions of environment and climate evolution. This project provides a comprehensive data base of major, minor and trace element and isotope tracers for tooth apatite using a variety of microanalytical techniques. The aim is to identify specific sedimentary environments and to improve our understanding on the interaction between internal metabolic processes during tooth formation and external nutritional control and secondary alteration effects. Here, we use the electron microprobe to determine the major and minor element contents of fossil and modern molar enamel, …
A German Validation Study of the Inventory to Diagnose Depression
The Inventory to Diagnose Depression (IDD), a self-rating scale designed to identify major depressive episodes (MDE) according to DSM-III, was validated in a sample of 83 inpatients. Depending whether the time criterion of MDE was included or omitted, 63 or 77 patients obtained a syndrome diagnosis of MDE established by means of a structured clinical interview (Polydiagnostic Interview) which served as yardstick. Sensitivity (84.1% with time criterion, 89.6% without time criterion), specificity (60%, 50%), predictive value (67.8%, 64.2%) and kappa (0.43, 0.29) were calculated and found to necessitate improvement for a reasonable application of the IDD in epidemiological and clinical setting…
Apatite and clinopyroxene as tracers for metasomatic processes in nepheline clinopyroxenites of Uralian-Alaskan-type complexes in the Ural Mountains, Russian Federation
Clinopyroxene and apatite are found to trace metasomatic processes in nepheline-bearing clinopyroxenites (tilaites) from the igneous, mafic-ultramafic Uralian-Alaskan-type complexes of Kytlym and Nizhny Tagil, Ural Mountains, Russian Federation. The clinopyroxenites consist predominantly of coarse-grained, partially to totally altered clinopyroxene phenocrysts in a matrix of fine-grained olivine, clinopyroxene, plagioclase, K-feldspar, and nepheline. Apatite occurs as idiomorphic inclusions (2O-, Na2O-, and Al2O3-bearing fluid. During conversion of the plagioclase, CaO and SiO2 were partitioned into the fluid. Altered areas in the clinopyroxene phenocrysts are characterized by the redistrib…