Rochechouart revisited again
Between the 8 th and 14 th of May, I met up with Jens Ormö to continue our research on the Rochechouart impact structure in France. In Spring 2019, Jens presented our results from the study of Rochechouart at the Lunar and Planetary Conference 2019. However, as he prepared the data he came to the ‘terrible’ conclusion – we need more data! Hence, we decided to return and log even deeper parts of the drill core than already done. We had visited the Rochechouart impact structure twice before and logged 66 m of the drill core SC2, which penetrates the crater infill. When we last left Rochechouart in May 2018, we were quite satisfied, as we believed our logging days were over. We assumed a sufficient depth had been reached that represented a depth deeper than when the resurge deposited (the water-carried sediments that entered the crater). To get the complete picture it turned out we needed to extend the logging of the drill core to at least an additional 25 m. Therefore, Rochechouart revisited again. Once again, we struggled with the logging of the SC2 core standing in a cold garage. Day by day, we added new data to the plots so we could follow the progress. When to reach the impact breccia? We started at 66 m depth in the crater fill sediments and continued for five days reaching down to 108 m depth. At this depth we had reached a few meters into a monomictic breccia, close to the crater floor. With these additional meters of logged core we do believe we have data for an exciting manuscript.
Philippe Lambert, who oversees and organizes the research at Rochechouart, was in Canada the week we came over, and we missed his good company. He organized the working space for us and had arranged our housing in the same holiday village where we had stayed before. It’s a very nice place, and this year we were the only guests staying there. It is very quiet, without Internet connection and only sporadic cellphone coverage. On the downside, the restaurant we frequently visit in Rochechouart, the Meteor unfortunately closed last Christmas. This was a serious loss not only for the food, but also the beer named ‘Meteor’ and produced by Hochfelden in Alsace.