Day 3 and 4 – Craters, Very Old Rocks, Fukushima and Extinctions

Here is my Goldschmidt summary part 3 comprising both day 3 and day 4. I had to prepare my own talk, that I gave on Thursday (day 4) so I had to put the blog on hold to practice.

Here are a few of the most interesting talks that I went to:

Fred Jourdan hailing all the way from Curtin University in South Australia gave a talk called  – Volcanoes, asteroid impacts and mass extinctions (abstract). In his funny and very interesting talk Dr. Jourdan asked the question what is responsible for mass extinctions in geologic history? There has always been considerable debate in the scientific community about what caused all of the mass extinctions that have taken place over geologic time. Was it the volcanoes or the meteorite impacts? Dr. Jourdan compared the dates mass extinctions and tied these to the dates of volcanic eruptions and meteorite impacts to see if any two or three occurred at the same time. He found that volcanic eruptions coincided with mass extinctions better than meteorite impacts and concluded that volcanoes have played a dominant role in mass extinctions throughout Earth history. However, meteorite impact dating needs to improve since they also play some role.

Dr. Phillippe Van Cappellen  from the University of Waterloo gave a fantastic keynote address (abstract) on the mysterious part of the groundwater world called the hyporheic zone. The hyporheic zone is the magical place in a stream bed where groundwater flows into the stream. Sounds pretty simple right? According to Dr. Van Cappellen, wrong! Very wrong. It turns out that the hyporheic zone is extremely complicated and can have major impacts on the flow of chemicals from groundwater into surface water. Imagine this scenario: a local aquifer is contaminated with PCB’s. This is bad, but they have not made it into the nearby stream yet, so we only have to remediate groundwater. However, these chemicals will get stored or released by the hyporheic zone and could potentially contaminate a larger area than we thought. Dr. Van Cappellen’s work aims to understand how the h-zone functions under different chemical conditions and what sort of environmental factors such as water level, organic content or freeze-thaw cycles can affect it.

John O’Neill a new professor from uOttawa gave a terrific talk called Earth’s Hadean Crust: Insights from the Nuvvuagittuq Greenstone Belt about some really, really, really old rocks (abstract). In fact he has dated some rocks located in Northern Quebec at 4.4 billion years old!!!! The Earth is only 4.6 billion years old so these rocks have been around right since the beginning. John’s talk was very well attended and he presented some very interesting results to prove that these rocks are so old. This is still a very controversial topic and I am sure that discussions will continue for quite a while.

The next talk was very interesting to me. Dr. Yasuyuki Muramatsu, one of the leaders in the field of radio-iodine research, presented his talk right before mine. His talk was called: Reconstruction of the Accident-Derived I-131 Deposition in Fukushima Through the Analysis of I-129 in Soil (abstract). A lot of iodine-131 was released from Fukushima, which as a short half life of 8 days. This meant that it was very difficult for researchers to map its fallout over Japan, which is essential. However, using iodine-129 as a proxy for iodine-131 is possible and Muramatu’s group set out to do just that and they produced some really nice maps showing the fallout pattern of iodine in Japan.

So that is it for Day 3 and 4. Instead of doing a Day 5 summary I am going to try and do an interview with someone and cover their research in a bit more detail. So stay tuned for that!

Cheers,

Matt