Dissertation (Metadaten)
Titel:Variations of Calcium Isotopes in Foraminifers Over the Past 24Ma
 
Autor:Alexander Heuser
 
URN:NBN:urn:nbn:de:gbv:8-diss-7132
 
Fakultät:Mathematisch-Naturwissenschaftliche Fakultät
DDC Sachgebiet:550 Geowissenschaften
 
Datum der mdl. Prüfung:12.02.2003
 
Referent(in):Prof. Dr. Anton Eisenhauer
Korreferent(en) Korreferentin:PD Dr. Reiner Botz
 
Beschreibung (original):Variations of calcium isotope ratios of foraminifer shells can be used for the reconstruction of past seawater temperatures or the recontruction of the evolution of teh Ca isotopic composition of seawater. This thesis presents a new multicollector TIMS technique for the measurement of Ca isotopes and a comparison of the Ca isotopic composition of different standard materials. A systematic study of cultured foraminiferes shows that variations the Ca istopic composition can be temperature dependent or can be independent of temperature. A model explaining the mechanisms of this different temperature dependence of Ca isotope fractionation of foraminifers is developed. Measurements of the Ca isotopic composition of foramninifers fractionating Ca isotopes independent of seawater temperature changes are used to reconstruct the evolution of the Ca isotopic composition of seawater over the past 24 Ma.
 
(übersetzt):keine dt.-spr. Zusammenfassung vh.
 
Schlagworte:TIMS ; calcium isotopes, kinetic fractionation, Globigerinoides sacculifer, Globigerinoides trilobus, Globigerinoides ruber, Globigerinella spp., Globigerina bulloides, Orbulina universa
Fossile Foraminiferen ; Schale ; Känozoikum ; Meer ; Wassertemperatur ; Calciumisotop ; Temperaturabhängigkeit ; TIMS
 
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