Mitarbeiter Sediment- und Isotopengeologie / Staff Sediment and Isotope Geology

Here we list active members of the Department and their research focus and list staff members who have moved on. Nachstehend finden Sie eine Liste der derzeitigen und ehemaligen Mitarbeiter und ihrer Forschungsaktivitäten.

Prof. Dr. A. Immenhauser
Cornelia Schäfer
Mathias Müller
Tanja Unger
Christine Zhong

Christine Zhong

Doktorandin/PhD (Immenhauser/Lokier)

IA 5/175

Tel: +49-234-32-23255

Research interests: Sedimentology, actualistic and fossil discontinuity surfaces, actualisistic carbonate depositional environments.

Forschungsinteressen: Sedimentologie, aktualistische und fossile Hartgründe, aktualistische Ablagerungsräume von Karbonaten.

Manfred Heinelt

Manfred Heinelt

Doktorand/PhD (Immenhauser/Bracke)

RUB und Fraunhofer IEG

Raum G1-004 & IA 5/175

Tel: +49-234-32-23255 &

Research interests: Sedimentology and petrography, Devonian carbonate geology, karstification, geothermal geology.

Forschungsineressen: Sedimentologie und Petrographie, Devonische Karbonat Geologie, Karstbildung, Geothermale Geologie.

Felix Jagert

Felix Jagert

Doktorand/PhD (Immenhauser/Wohnlich)

Fraunhofer IEG

Raum G1-1-014

Tel. +49-234-32-10838 &

Research interests: Evaluation of hydraulic efficient fracture-systems and characterization of deep ground-water-flow using geophysical well logging, hydraulic field tests and 3D geological modelling.

Forschungsinteressen: Hydraulische effiziente Störungs-Systeme. Charakterisierung von tiefen Grundwassereigentschaften mithilfe von Geophysik, Untersuchung von Borungen, hydraulische Tests im Gelände und 3D Modellierung.

Ozioma Uwakwe

Ozioma Uwakwe

Doktorandin/PhD (Immenhauser/Riechelmann)

IA 5/179

Tel: +49-234-32-23255

Research interests: Experimental approaches to carbonate research. Topics include hydrothermal scaling experiments or cave-analogue experiments.

Forschungsinteressen: Experimentalle Ansätze in der Karbonatforschung. Experimente zum Thema geothermale Versinterung und Analoge von Karbonatfällung in Höhlen.

Vivien Folliot

Vivien Folliot

Doktorand/PhD (Immenhauser/Della Porta)

IA 5/173

Tel.: +49-234-32-25457

Research interests: Dolomite Mountains, early diagenetic dolomitisation, diagenesis, geochemistry.

Forschungsinteressen: Dolomiten, frühdiagenetische Dolomitisierung, Diagenese, Geochemie.


Max Berndsen

Doktorand/PhD (Immenhauser/Licha/Alms; Fraunhofer IEG)

RUB & Fraunhofer IEG

Raum G1-004 &

Research interests: Geochemistry and petrology, carbon capture and storage, CO2 mineralisation, geothermal geology.

Forschungsinteressen: Geochemie und Petrologie, Kohlenstofffixierung, CO2 Mineralisation, geothermale Geologie.



Kevin Stevens

Dr. Kevin Stevens

Scientist/Wissenschaftlicher Mitarbeiter

IA 5/161

Tel: +49-234-32-25459

Research interests: Paleobiology of cephalopods and fishes, microstructures, geochemistry and diagenesis of biogenic carbonates and phosphates.

Forschungsinteressen: Paläobiologie von Cephalopoden und Fischen, Mikrostrukturen, Geochemie und Diagenese von biogenen Karbonaen und Phosphaten.

Janina Falkenberg

Janina Falkenberg

PhD/Doktorandin (Mutterlose)

IA 5/161

Tel: +49-234-32-25459

Research interests: micropalaeontology, calcareous nannofossils, archaeometry, provenance analysis and archaeothermometry of historic mortars and mortar-based materials.

Forschungsinteressen: Mikropaläontologie, kalkige Nannofossilien, Archäometrie, Provenanz Analyse und Archäothermometrie von historischen Mörteln und mörtel-ähnlichen Materialien.

Dr. Alexander Pohle

Dr. Alexander Pohle

Scientist/Wissenschaftlicher Mitarbeiter

IA 5/181

Tel: +49-234-32-25584

Research interests: Paleobiology of fossil cephalopods, Palaeozoic nautiloids, Mesozoic coleoids, Bayesian phylogenetic inference.

Forschungsinteressen: Paläobiologie fossiler Kopffüßer, Paläozoische Nautiloideen, Mesozoische Coleoideen, Bayes'sche phylogenetische Inferenz.

Photo - Riechelmann
Dr. Sylvia Riechelmann

Kathrin Delli Carri

Technical Assistant/Chemisch-Techn. Assistentin

IA 01/159

Tel: +49-234-32-25455/24814

Dr. René Hoffmann
Sabine Weisel

Sabine Weisel


Operator/Technische Angestellte

IB 02/163
Tel: +49-234-32-24136

Mikroanalytical laboratory, REM CL EMP

Daniel Herwartz
Prof. Dr. Daniel Herwartz

My present research focusses on the oxygen cycle. This includes the water cycle and chemical sediments precipitating from water. Oxyanions such as PO43-, SO43-, CO32- or Si(OH)4 dissolved in water exchange isotopes with H2O and thus conserve an isotopic record over Earth history. In the classic approach the 18O/16O isotope ratio is used to read this record, e .g. to reconstruct paleo-temperatures from carbonate rocks. Additional 17O/16O ratios provide a second dimension to the classic oxygen isotope system. This allows testing if paleotemperatures are accurate. Reconstructions of present and past water cycles are improved and critical parameters such as paleo-relative humidity can be reconstructed. Air O2 comprises particularly low 17O/16O ratios providing a natural tracer for respiration. My goal is to fully understand the underlying processes and oxygen fluxes in order to use the respective chemical sediments as faithful archives for reconstructing Earth’s history. This quantitative approach is useful to trace any oxygen bearing compound in nature and is thus suitable for a broad variety of topics. Previous research topics include fossil bones, dating of high-pressure rocks, early Earth, Snowball Earth events and cosmochemistry.

Kontakt: Lehrstuhl Sedimentäre Geochemie

Ruhr-Universtät Bochum
Fakultät für Geowissenschaften
Institut für Geologie, Mineralogie und Geophysik; Raum: IA E5/179
Universitätsstraße 150
44801 Bochum

Tel.: +49-(0)234-32-22307


Full publication list on Google Scholar:

Selected Publications:

Herwartz D., Pack A., Nagel T.J. (2021): A CO2 greenhouse efficiently warmed the early Earth and decreased seawater 18O/16O before the onset of plate tectonics. Proceedings of the National Academy of Sciences 118 (23), e2023617118.

Herwartz D. (2021) Triple oxygen isotopes in igneous, metamorphic and hydrothermally altered rocks. In: Triple oxygen isotopes on Earth, edited by Andreas Pack and Ilya Bindeman, Reviews in Mineralogy and Geochemistry 86, 291-322.

Herwartz D., Surma J., Voigt C., Assonov S., Staubwasser M. (2017) Triple oxygen isotope systematics of structurally bonded water in gypsum. Geochimica et Cosmochimica Acta 209, 254-266.

Herwartz D., Pack A., Krylov D., Xiao Y., Muelenbachs K., Sengupta S., Di Rocco T. (2015) Revealing the climate of snowball Earth from Δ17O systematics of hydrothermal rocks. Proceedings of the National Academy of Sciences 112, 5337-5341.

Herwartz D., Pack A., Friedrichs A., Bischoff A. (2014) Identification of the giant impactor Theia in lunar rocks. Science 344, 1146-1150.

Pack A. and Herwartz D. (2014) The triple oxygen isotope composition of the Earth mantle and understanding variations in terrestrial rocks and minerals. Earth and Planetary Science Letters 390, 138-145.

Herwartz D., Tütken T., Jochum K.P., Sander P.M. (2013) Rare earth element systematics of fossil bone revealed by LA-ICPMS analysis. Geochimica et Cosmochimica Acta 103, 161-183.

Herwartz D., Münker C., Tütken T., Hoffmann J. E., Wittke A., Barbier B. (2013) Lu-Hf systematics of fossil biogenic apatite and their effects on geochronology. Geochimica et Cosmochimica Acta 101, 328-343.

Herwartz D., Tütken T., Münker C., Jochum K.P., Stoll B., Sander P.M. (2011) Timescales and mechanisms of REE and Hf uptake in fossil bones. Geochimica et Cosmochimica Acta 75, 82-105.

Herwartz D., Nagel T.J., Münker C., Scherer E.E., Froitzheim N. (2011) Tracing two orogenic cycles in one eclogite sample by Lu-Hf garnet chronometry. Nature Geoscience 4, 178-183.