This talk will focus on the end-Triassic mass extinction, one of the “Big Five” extinction events of Earth history, and how it set the scene for the most famous period of geological history: the Jurassic. The end-Triassic extinction is rather poorly understood, but British geological successions provide useful information on its causes and consequences. Volcanism, global warming, and ocean anoxia are all thought to have been involved in the extinction. A second mass extinction – particularly harsh for ammonoids - followed in the early Jurassic, again with its origins in volcanism and anoxia. Together, the 17 million years between 200 and 183 Ma represent a tough time for life on Earth, and much of the evidence for this lies on our doorstep.

Biography

David's research looks at the record of environmental change during Earth’s greatest mass extinctions. His current NERC-funded research investigates three crises that occurred between the Middle Permian and end Triassic - an interval of extremes of climate, extinction and evolution - in the "Boreal Realm" of northern high latitudes. His focus is the role of major (large igneous province) volcanism in extinction scenarios, and the effects of warming, oceanic oxygen depletion and acidification on marine ecosystems. David is a field geologist who has worked in 30 countries and has published on extinctions from 445 million years ago to the present.