Job Vacancies Available
Innovative Training Network (ITN-ETN)
ESR01—PhD position - filled
Brachiopods from modern and Phanerozoic habitats: Archives of spatial and temporal variations
CONTACT: Maria Aleksandra Bitner, Polish Academy of Sciences, Poland, e-mail: bitner(at)twarda.pan.pl
SHORT DESCRIPTION The aim of this PhD project is to study elemental and isotopic composition (with a focus on oxygen, carbon and magnesium) in modern brachiopod shells from various natural and laboratory controlled habitats, and using them for proxy calibration. The obtained results will be used for reconstruction of ancient environments and climates based on fossil brachiopod studies.
ESR02—PhD position - filled
Evaluating the biomineralization and chemical differentiation of modern brachiopod archives
CONTACT: Claire Rollion-Bard, Institut de physique du globe de Paris (IPGP), France, e-mail: rollion(at)ipgp.fr
SHORT DESCRIPTION This PhD project focuses on the determination of the biomineralization processes and their impact on geochemical proxies in brachiopods in order to evaluate their potential use as a chemical archive for geochemical proxies in ancient seawater. Measurements will essentially be performed on brachiopod specimen grown under controlled laboratory conditions (T, pH). The ultimate goal is to decipher the vital effects on the proxy record.
ESR03—PhD position - filled
The macro-structure of modern and fossil brachiopod archives
CONTACT: Lucia Angiolini, Universita degli Studi di Milano, Italy, e-mail: lucia.angiolini(at)unimi.it
SHORT DESCRIPTION This PhD project examines the macro- and chemico-structure of modern and fossil brachiopod shells to reconstruct evolutionary changes and fabric differentiation of the main brachiopod classes during the Phanerozoic, and to test their veracity in withstanding post-depositional alteration. This will be achieved through a combination of methods involving field collections, systematics, SEM ultrastructural analyses and geochemical trace-isotope analyses. The goal is to test the brachiopod archive's potential for reconstructing the chemical evolution of Phanerozoic seawater.
ESR04—PhD position - filled
Magnesium isotopes in Phanerozoic brachiopods: Implications for the oceanic Magnesium cycle, hydrothermal fluxes, and dolomitization events
CONTACT: Michael Komárek, Czech University of Life Sciences, Czech Republic, komarek(at)fzp.czu.cz
SHORT DESCRIPTION This PhD project generates a Phanerozoic marine Mg isotope record, based on the analysis of δ26Mg values in calcitic shells of modern and fossil brachiopods. The inferred δ26Mg record of Phanerozoic seawater will then be used to reconstruct and model the history of hydrothermal activity and/or dolomite formation in the Phanerozoic oceans with implications for the evolution of marine Mg/Ca ratio over geological time.
ESR05—PhD position - filled
Lithium isotopes in Phanerozoic brachiopod shells: Implications for the continental weathering flux
CONTACT: Tomáš Magna, Czech Geological Survey, Czech Republic, e-mail: tomas.magna(at)geology.cz
SHORT DESCRIPTION This PhD project generates a Phanerozoic marine lithium (Li) isotope record, based on the analysis of lithium isotope (δ7Li) values in calcitic shells of modern and fossil brachiopods. This will extend and complete the existing information on the evolution of seawater δ7Li and Li/Ca ratios. The latter knowledge will provide important quantitative information on continental weathering fluxes throughout the Phanerozoic with implications for the Earth's global atmospheric CO2 budget and paleo-climate history.
ESR06—PhD position - filled
High resolution isotope and trace element ratios during the Triassic/Jurassic mass-extinction
CONTACT: Adam Tomašovych Slovak Academy of Sciences, Slovakia, e-mail: Adam.Tomasovych(at)savba.sk
SHORT DESCRIPTION This project will focus on the documentation of temporal and spatial changes in temperature and seawater chemistry across the Triassic/Jurassic boundary (~200 Million years ago). This particular time is characterized by one of the largest mass extinctions of marine species during the Phanerozoic. We will use brachiopod shells as archive and determine trace element ratios, stable (δ18O and δ13C) as well as traditional and non-tradition isotope systems (δ11B, δ26Mg, δ44/40Ca, clumped isotopes Δ47) in order to gain marine environmental proxy information. Spatially the study will focus on stratigraphic sections in the Northern Calcareous Alps and in the Carpathians.
ESR07—PhD position - filled
Test Chromium and Uranium stable isotopes in brachiopods as a paleo-redox proxy in seawater
CONTACT: Robert Frei, University of Copenhagen, Denmark, e-mail: robertf(at)ign.ku.dk
SHORT DESCRIPTION: This PhD project focuses on the development and use of non-traditional stable isotope systems (chromium and uranium) in brachiopods for their potential use as paleo-redox proxies in seawater. The project is a combination of methods development in the laboratory, a test period in which the systems are applied to control-cultured brachiopods, and an applications part during which the systems is applied on modern and fossil shells and associated carbonates from some important evolutionary periods in Earth's history. The ultimate goal is to link the systems to continental weathering and to climate change on Earth.
ESR08—PhD position - filled
Clumped isotopes in brachiopods as an indicator of seawater and diagenetic temperatures
CONTACT: Jens Fiebig, Goethe University, Germany, e-mail: Jens.Fiebig(at)em.uni-frankfurt.de
SHORT DESCRIPTION: This PhD project is focused on clumped isotope analysis of carbonates (e.g. brachiopods). It aims at i) reducing the sample size required for a single analysis applying the common acid bath technique, ii) investigating the temperature dependence of isotopic clumping (Δ47) for brachiopods, iii) reconstructing the temperature and the oxygen isotopic composition of Phanerozoic seawater, iv) determining diagenetic alteration temperatures.
ESR09—PhD position - filled
The micro(µm)- and nano(nm)-structure of modern and fossil brachiopod archives
CONTACT: Erika Griesshaber, Ludwig Maximilian-University, Germany, e-mail: email@example.com
SHORT DESCRIPTION The focus of the PhD project will be the investigation of the hybrid nature of modern and fossil brachiopod shells and coral skeletons. This involves: (i) imaging the distribution pattern of the biopolymer matrix within the hard tissue, (ii) characterization of mineral phases that form the skeletal elements and (iii) determination of crystal orientations for an understanding of biological mineralization patterns.
ESR10—PhD position - filled
Variation of Boron element and isotope ratios in Phanerozoic brachiopod shells; Implications for the marine carbonate cycle
CONTACT: Volker Liebetrau, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, e-mail: vliebetrau(at)geomar.de
SHORT DESCRIPTION This research task will extend the existing Phanerozoic δ44/40Ca- and δ88/86Sr- records for (i) time series of δ11B, (ii) and test its reliability as a proxy for continental weathering and pH variations in the ocean. This will have major implications for variations of the changing Phanerozoic carbon cycle.
ESR11—PhD position - filled
Dolomitization of modern and fossil brachiopods – experimental approach
CONTACT: Martin Dietzel, Graz University of Technology, Austria, e-mail: martin.dietzel(at)tugraz.at
SHORT DESCRIPTION This project is based on laboratory-controlled dolomitization experiments performed by hydrothermal treatment of brachiopod shells. The evolution of dolomite formation will be monitored by the chemical composition of the aqueous solution as well as the chemical and (micro/nano)structural evolution of the solid throughout the dolomitization and by applying traditional (δ13C, δ18O) and non-traditional (e.g. δ44/40Ca, δ26/24Mg, δ88/86Sr, Δ47) stable isotope systems. The study aims to (i) deciphering individual diagenetic reaction pathways, (ii) evaluating the degree of diagenesis and chemical alteration, and (iii) elucidating the implications to isotope records of the Phanerozoic seawater and/or of diagenesis.
ESR12—PhD position - filled
Testing the laser ablation technique for in-situ determination of non-traditional stable isotopes at fine-scale variation in marine brachiopods
CONTACT: Jan Fietzke GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, e-mail: jfietzke(at)geomar.de
SHORT DESCRIPTION This PhD project intends to develop methods using LA-MC-ICP-MS (Laser Ablation Multi Collector Inductively Coupled Plasma Mass Spectrometry) for the spatially highly resolved determination (named "isotope imaging") of non-traditional stable isotope (e.g. δ11B, δ44/40Ca, δ26/24Mg, δ88/86Sr) ratios on carbonate samples. The main goal is the acquisition of representative isotopic images in pristine sample material to allow for evaluation of systematic variations of non-traditional stable isotopes and relate them to morphological features (e.g. growth increments).
ESR13—PhD position - filled
From warm to cold: high resolution trace element and isotope ratios during the late Miocene and the Pliocene/Pleistocene transition from ancient warm to modern cold climates
CONTACT: Boaz Lazar Hebrew University Jerusalem, Israel, e-mail: boaz.lazar(at)mail.huji.ac.il
SHORT DESCRIPTION This PhD project focuses on the development and use of non-traditional stable isotope systems of mainly Calcium (Ca, δ44/40Ca) and Strontium (Sr, δ88/86Sr) in brachiopods and pectinids for their potential use as proxies for the geochemical evolution of Phanerozoic seawater. In particular we aim to investigate two important Phanerozoic time intervals: (i) the upper Miocene post-Messinian Salinity Crisis (MSC) and (ii) the warm/cold Pliocene/Pleistocene transition in the circum-Mediterranean in comparison to a large oceanic basin such as the Pacific Ocean (e.g. brachiopods of the Careaga sandstone, Upper Pliocene, California).
ESR14—PhD position - filled
Calibration of elemental and isotope proxies by inorganic precipitation experiment
CONTACT: Albrecht Leis Joanneum Research Forschungsgesellschaft MBH, Austria, e-mail: albrecht.leis(at)joanneum.at
SHORT DESCRIPTION This PhD project focuses on the element discrimination and isotope fractionation processes in inorganic calcium carbonates precipitated under laboratory controlled conditions. A main task is the impact of organic acids on carbonate precipitation and proxy signals. The evolution of carbonate formation will be monitored by using elemental ratios and applying traditional (δ13C, δ18O) and non-traditional (e.g. δ7Li, δ11B, δ44/40Ca, δ26/24Mg, δ88/86Sr, Δ47) stable isotope systems. Emphasis will be given on the partitioning of redox-sensitive elements (e.g. Cr, U) and related isotope systems (δ53/52Cr, δ238/235U) in artificially precipitated calcium carbonate phases.
ESR15—PhD Position - filled
Determination of Carbon Isotope Variations above natural and artificial reefs
CONTACT: Claudia Bouman Thermo Fisher Scientific (Bremen) GmbH, Germany, e-mail: claudia.bouman(at)thermofisher.com
SHORT DESCRIPTION GEOMAR holds a variety of culturing facilities among them a large out-door benthos mesocosm system and a small indoor coral reef aquarium in order to perform experiments to understand carbon cycling in the ocean. Results gained from these laboratory controlled culturing experiments will be compared to field experiments in order to generate a mechanistic understanding of related processes in the ocean and in coral reefs in particular.
By using a Delta Ray IRIS system we will carry out δ13C measurements in the coral reef aquarium air and in attached semi-enclosed containers where air is in contact with the aquarium water in order to monitor diurnal variations of the carbon system. The latter include normal conditions as well as CO2-enriched water simulating ocean acidification. Delta Ray IRIS measurements will be cross checked with conventional IRMS.