Tracing global ocean oxygenation from calcitic brachiopods

August 4, 2020Publication, Research, Students and postdocs

The uranium isotope composition of seawater provide insights to how much sediment burial occurs globally in anoxia settings. Therefore, it is desirable to measure uranium isotopes to track the oxygenation state of the oceans through geological time. However, there is currently no geological archive that can reliably record the composition of ancient seawater. Calcitic brachiopods … Read More

New GCA paper: Volcanic eruptions triggered repeated marine anoxia and reveal global-scale feedbacks during the Permian-Triassic mass extinction 250 million yeers ago

April 18, 2020Publication, Research, Students and postdocs, Uncategorized

The largest animal extinction event in recorded history occurred 251 Ma at the Permian-Triassic boundary coinciding with expansive marine anoxia. In a new study, led by postdoc Feifei Zhang, of a greatly expanded dolomite section from the Carnic Alps, Austria, marine anoxia is found to have expanded in two pulses separated by ~100,000 years. Global … Read More

Julius and Alvaro presents new U isotope results in Ascona

October 31, 2018Presentations, Students and postdocs, Talk

PhD student Álvaro Del Rey and MSc Julius Havsteen participated in the Uranium Biogeochemistry Conference in Ascona (Switzerland). Results from Julius’ thesis were presented at the poster session Wednesday afternoon, which put forward new constraints on the global oxygenation state of the Late Silurian ocean and discuss the use of brachiopods instead of bulk carbonate samples … Read More

Nordic Winter Meeting January 2018 – 4 presentations

December 18, 2017Outreach, Presentations, Research, Students and postdocs

Our group will give several presentation at the Nordic Winter Meeting at DTU in Lyngby, Denmark Wednesday Jan 10, 2018 10.00-11.00 Student poster presentations Magnus A. R, Harding “Surface analyses of fossil leaves” Julius C. Havsteen “The Silurian Lau event – testing plant weathering as driver for ocean anoxia and animal extinction”   Thursday Jan 11, … Read More

New paper in press: Ocean redox conditions between the Neoproterozoic Snowballs

December 18, 2017Publication, Research, Students and postdocs

A new paper on the redox conditions in the oceans after the Sturtian and before the Marinoan ‘Snowball’ glaciations is now press in Precambrian Research. Our results suggest that oceans remained largely anoxic after the Sturtian glaciation and that something else triggered oxygenation of the Ediacaran oceans after the Marinoan glaciation. This ‘something’ could be due to the way animals affect the global … Read More

Julius C. Havsteen starts his MSc thesis project in January 2018

December 18, 2017Research, Students and postdocs

MSc Geology student Julius C. Havsteen starts his thesis project in January 2018, where he will be exploring changes in the the globally integrated ocean oxygenation state during the Silurian Lau event. The Lau event is the largest carbon isotope excursion in the Phanerozoic, recording a brief period of dramatic changes in the Earth system. Nevertheless, the driving … Read More

Welcome to PhD student Alvaro Del Rey

December 18, 2017Research, Students and postdocs

On September 1, Alvaro del Rey joined the lab as a PhD fellow in geobiology and experimental isotope geochemistry. Alvaro has a background in igneous petrology and will now be working on uranium isotopes in carbonate rocks during Mid-Paleozoic events.