4 Aug 2020

Tracing global ocean oxygenation from calcitic brachiopods

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 […]

18 Apr 2020

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

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 […]

1 Mar 2020

Expansive ocean anoxia during the Late Devonian Hangenberg event

Marine animal extinction events have occurred episodically over the past 550 million years with expansive marine anoxia as the proximate kill mechanism. New evidence from a carbonate section in South China (Long’an) shows that the Late Devonian Hangenberg event should be counted as one such events. Postdoc Feifei Zhang have analyzed uranium isotopes in a […]

31 Oct 2018

Julius and Alvaro presents new U isotope results in Ascona

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 […]

18 Dec 2017

Nordic Winter Meeting January 2018 – 4 presentations

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, […]

18 Dec 2017

Magnus A. R. Harding will join the group as a research assistant

Beginning in January 2018, Magnus A. R. Harding will continue working in the group now as a research assistant. Magnus’ main focus will be to extend ongoing studies of the chemical composition of fossil plant leaves.  

18 Dec 2017

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

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 […]

18 Dec 2017

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

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 […]

18 Dec 2017

Welcome to PhD student Alvaro Del Rey

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.