On the end-Triassic mass extinction – In Danish

This spring an entire issue of the Danish Geoscience journal Geoviden was dedicated to our research project “The Triassic–Jurassic boundary: Impact of a Large Igneous Province on the geobiosphere”. Geoviden is a popular science magazine aimed at high school students and everyone else interested in geology and geography. Our issue is called “A crisis in the history of life” and  presents the background, hypothesis and progress of our Geocenter Denmark financed project. Unfortunately for non-Scandinavian readers it is in Danish. It is richly illustrated and covers various aspects of our research. It can be downloaded for free using this link, so feel free to check it out: Geoviden No 1 2016: “En krise i livets historie”

Front page illustration by Stefan Sølberg, GEUS.

EGU2014 Thursday: “Volcanism, Impacts, Mass extinctions and Global environmental change” – a brief review of two talks.

Thursday afternoon at the EGU2014 was totally dedicated to the session “Volcanism, Impacts, Mass extinctions and Global environmental change” in which I also presented a talk. The session contained a total of eleven oral presentations covering various subject within the above mentioned topics. The first four talks were on the volcanism of the Siberian Traps and the end-Permian mass extinction event.

In the first talk, Seth Burgess presented new high-resolution geochronological data for the intrusives of the Siberian Traps. Burgess and his colleagues had used the same analysis and standards on not only zircons from the Siberian Traps, but also on zircons from the ash-layers bracketing the end-Permian mass extinction level at the GSSP Meishan in China. According to these new datings all the dated intrusives post-date the end-Triassic mass extinction event. Seth Burgess stated that although these data could be taken as “the nail in the coffin for the theory that the intrusive activity caused the mass extinction” he didn’t believe that they did. He then went on to explain that the majority of the intrusives of the Siberian Traps are situated at depths and those that have been dated are the ones that are accessible, probably producing a biased record.

This was good news for the second speaker, Henrik Svensen, who presented a talk on the sill-induced evaporite and coal metamorphism of the Siberian Traps. Svensen and colleagues showed that the Siberian Traps contain very thick sills that have been emplaced into both coal-bearing sediments and salt deposits, with the potential for degassing of both green house gases (CH4, CO2), aerosols (SO2), and ozone destructive gases (CH3Cl, CH3Br), which could explain the end-Permian biotic crisis.

A fuzzy picture of Henrik Svensen and his audience.

 

EGU2014: Highlight Tuesday

The number 1 highlight of Tuesday was the Arthur Holmes medal lecture by Kevin C.A. Burke: Plume Generation Zones On The Core Mantle Boundary: their origin and what they tell about how the Earth works – and how it has worked.

Kevin Burke giving his medal lecture at the EGU2014

Burke, who due to health issues had to remain seated during his hour-long lecture, captivated his audience with his warm and humoristic and insightful review on how and where in the Earth’s interior volcanic plumes are formed. If you are interested in large igneous provinces, flood basalts, hot spots etc I strongly recommend you to check out the streamlined talk at the EGU2014 website.