I’ve just returned from the Geological Society of America (GSA) annual conference. It was held this week (October 19-22) in Vancouver, British Columbia and my PhD student Teddy Them and I attended. It turned out to be a great meeting this year and well worth the trip.
Teddy gave a talk on some his dissertation research on Monday morning in the session Organic-Rich Mud Rocks: Geochemistry, Physical Properties, and Paleo-Environments. The results Teddy presented show that the large negative carbon isotope excursion that occurred during the Toarcian Stage of Jurassic can be found at several locations in Alberta. This is very important because it shows that this excursion reflects a global perturbation to the carbon cycle 182 million years ago. This excursion is though to be linked to the wide-scale volcanic eruptions and the Toarcian Ocean Anoxic Event (T-OAE), a time of widespread oxygen deficiency in the oceans.
Here is a link to the abstract for his talk: Rapid environmental changes during the Early Jurassic (Pliensbachian to Toarcian Stages) in Western North America recorded in the geochemistry of organic-rich mud rocks
I gave an invited talk in a session that highlighted research on the relationship between the environmental changes and evolutionary changes that occurred during the Ordovician Period (485 to 443 million years ago). My talk centered on the changes that occurred in the sulfur cycle during that latest portion of the Ordovician and how they provide information on changes in the redox chemistry of the oceans going into and during the mass extinction (the second largest in Earth History behind the Permo-Triassic) that occurred during that time.
Here’s a link to my abstract: Sulfur isotope evidence for Late Ordovician ocean oxygenation: Implications for the drivers of the Hirnantian Extinction.
Below is a list of other abstracts from the meeting that included members of the VT Sedimentary Geochemistry Group. The first three where given by our collaborators Darren Gröcke and Andrew Caruthers at Durham University in the UK on our work on rocks from the Early Jurassic Period (190 to 174 million years ago) located in Nevada.
- Expression of the Toarcian carbon isotope event in a siliceous black shale from New York Canyon, Nevada
- Early Jurassic paralic to shallow marine microbial environments of Nevada: A unique record of the Toarcian Oceanic Anoxic Event
- Ammonite biostratigraphy of the Early Jurassic (Pliensbachian-Toarcian) Sunrise Formation, Gabbs Valley and Clan Alpine Mountains, West-Central Nevada
Last, but certainly not least, was the presentation given by Rowan Martindale from UT Austin. This meeting was the reveal of the Lagerstätte (a deposit of exceptionally preserved fossils) that we first discovered while conducting fieldwork in Alberta two summers ago.
Thanks to everyone that stopped in and listened to our talks and saw our poster presentations!