Unfortunately we had to abandon the first hole (Site WLRIS-6A in the map) after only 31 m of drilling. It was all composed of coarse sand and gravel (see photo) with just a little bit of mud. Coarse-grained sediments are very difficult to drill, because they are not coherent. The drillhole becomes unstable and is caving in, which can cause the drill bit to get stuck in the sea floor. To prevent this, we had to abandon the hole and go to a different site to reach our objectives. The sand and gravel was an unexpected discovery and we are still trying to explain how it got there, although we know it came from Antarctica. Because we are exploring a part of the Antarctic margin where no one has ever drilled before, such surprises are expected. Our next site is to the northwest of WLRIS-6A. We are there now, and drilling has just started. When I wake up tomorrow morning there will be more core and there will be more discoveries. Stay tuned, it will get even better.
No comments:
Post a Comment