Talk 6/7-2022: Dahl colloquium at IPM, Hamburg University

July 4, 2022By Tais W DahlUncategorized

July 6th, 2022 @ 17:15. Institut für Pflanzen und Mikrobiologie (IPM) is at Ohnhorststr. 18 in Klein Flottbek, a suburb of Hamburg. Tais will give a lecture for the Institute for Plants and Microbiology (IPM) at Hamburg University entitled: “Atmospheric oxygenation and climatic cooling during the early colonization of the terrestrial environment by plants”. The presentation will … Read More

Telling actual time in the rock record

May 5, 2022By Tais W DahlUncategorized

We have discovered a new method to tell time in the Geological record, using core scanning XRF analyses, which we have now applied to Cambrian and Ordovician rocks to refine the Geological Time Scale. The study, led by my PhD student Zhengfu Zhao, is now published in Nature Communications. The new method was first discovered … Read More

EarthTalks at GEOCENTER Denmark

April 23, 2021By Tais W DahlUncategorized

The Section for Geobiology at GLOBE has helped organizing the spring season of EarthTalks 2021, and we welcome interested students and researchers to participate over Zoom (link below). The talks will not be recorded. Earth Talks Lecture Series – Spring 2021 Friday afternoons 14:00-15:00 DK time (sharp) 23/4 – Prof. Sigur∂ur Gislason, University of Iceland The … Read More

Did land plants alter erosion rates on Earth?

March 28, 2021By Tais W DahlUncategorized

A discussion arises from the recent review article in Chemical Geology, where Tais W. Dahl and Susanne Arens concluded that land plants did not forever increase the physical weathering rates of the continental crust. This conclusion was reached from the records of preserved sediment rock volume and the timing of plant-assisted weathering as recorded in … Read More

The Carlsberg foundation supports field work in Siberia

January 27, 2021By Tais W DahlUncategorized

The Carlsberg Foundation is sponsoring field work led by Tais W. Dahl to Arctic Siberia, where an important climate catastrophe is recorded in marine sedimentary rocks. The expedition will bring back data and samples deposited in the oceans during a climate event that caused sulfidic anoxia to suddenly expand in warming oceans and wipe out … Read More

Press release: Early animals had a shorter day

October 12, 2020By Tais W DahlUncategorized

In a brief story published in Danish on Videnskab.dk, Aske L. Sørensen and Tais W. Dahl explain one of the consequences of their latest EPSL paper: Earth was spinning faster 500 million years ago. The scientific paper entitled “Astronomically forced climate change in the Late Cambrian” documents Milankovitch-cycles in two drill cores through the Alum … 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, 2020By Tais W DahlPublication, 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