IODP Sixth Report - Bit by bit.
Our scientist-at-sea, PhD student Steffen Jorgensen, aboard the JOIDES Resolution sends his sixth report.
After the last success we were ready to ride that wave to the new drilling site! Everything went fine through the sediment layer and into the top of the basalt until about 89 meters down in the hole, which was approximately 30 meters into the basalt: suddenly we couldn’t advance any further.
After 5 hours of trying without getting any deeper they decided to pull the drilling bit back up to inspect it for any damage. Damaged it was, to say the least. The drill bit normally consists of three rotating cone bits. Two were ripped completely off and the third was seriously damaged. The biggest problem was that the two big cone bits that had been ripped off were left at the bottom of the hole. In order to get any further we needed to get them out of the hole.
There are several “fishing” tools that can be used to do this; however, the problem is that a “best case” scenario would involve at least two trips up and down the hole. Given the round-trip time, and the low chances of actually being able to recover everything, it was decided to abandon the hole and start a new one.
The drilling bit is a massive tool made of tungsten carbide, not something that you just pull apart with your everyday basaltic rock. The reason for the failure was most likely an imperfection in the construction. The pressure that is put on the drill bit is up to 50 000 pound, so just a slight manufacturing error will lead to calamities.
Well, that is at least what the drilling engineers concluded. I, of course, have another and much more plausible explanation – diamonds. We simply hit a layer of diamond and as everybody knows that is a pretty hard mineral, able to cause some serious damage, even to tungsten carbide. The reason that nobody have succeed in retrieving diamonds from the deep seafloor is naturally that every time we encounter a layer, the bit gets messed up and the drilling stops. Trained geologists will likely reject my theory; however, I am waiting for them to prove me wrong!!!
Fun aside; naturally this was not an optimal situation as we had lost some valuable time. However, everything good comes to those who wait and last night the first hard rock cores (pillow lava) came on deck from the newest hole. We are aiming at recovering 300 meters of hard rock at this site before installing the CORK.
What else have I been up to since the last report: A couple of skype conferences with high school classes around the world. A short article on Methanopyrus Kandleri that can be viewed at http://www.darkenergybiosphere.org/adoptamicrobe/2011/10/introduction-to...
Hump day celebration. My birthday. Discovering the fun of playing Wii. Starting to appreciate baseball – in lack of better (read European football) spectator sports options,.Have an ongoing rowing competition with Wolfgang Bach - needless to say he is in the lead!
That’s all for now folks, any questions please feel free to email me at any time.
Have a question? Send it to Steffen!
Links relating to the cruise:
- Daily reports on IODP web site
- JOIDES Resolution web site
- Adopt a Microbe Project
- expedition 336 on Twitter (scroll down)
Editor’s questions to Steffen:
1) How is the next site going? Same kind of thing - differences?
Other than the hole being dug deeper coring it will be the same as the last hole with respect to type of crust – basalt.
2) What do you do to the samples to prepare them for being transported back to labs on land?
I just freeze them at -80C to preserve them for later work back in labs on land.
3) What will you be looking for when you finally get around to looking at the samples back on land?
I will be doing DNA work looking at the presence of Archaea. No one has ever looked for Archaea in deep basalts before.
4) Are the drill holes being dug on this expedition gathering the deepest microbiology samples that have ever been gathered?
No, by no means. The deepest as far as I remember is 1627 meters through sediments near Newfoundland. But this is the first dedicated drilling for microbiological sampling in deep seafloor crust.
5) What information is anticipated from drilling and sampling this deep?
We just cross our fingers that we can get out DNA at all from the sample material. The sample material is very compacted and the cells are located in cracks and veins in the rock, so the biomass per sample is likely to be extremely low. We do not know exactly what to anticipate, but it seems reasonable to find micro-organisms involved in the oxidation/reduction of metals.