Yes. I know that this title leads one to believe that I have no appreciation for paleoceanography. This is simply untrue. The paleo lesson in which we participated was a very engaging process – and the outcome was enlightening. But I just happen to be a little more excited about the mafic rocks we saw today since Katie Inderbitzen (our instructor) shared a big secret with us. Perhaps it is not a secret for most geologists, but it was for me! But first, here is a section of the core:
We had a chance to take about 20 minutes to describe the core and put together a stratigraphic column (can you imagine that, sedimentologists? Talk about your LUMPERS!). Anyway, I felt pretty confident (most of you know that I am seldom confident) that we had an ophiolite suite! How exciting! It turns out that I was close. Katie told us it was part of an ocean crust profile. But with the lithology pattern so indicative of ophiolite, I had to ask her why it wasn’t.
When we got back to the conference/lecture room, Katie told us about some of the distinct differences between MOR ocean crust profiles and ophiolite profiles. Ophiolites come from a gigantic magma chamber compared to smaller source with the MOR rock profiles. Secondly, P-wave velocities are a lot different in ophiolite sequences when compared to MOR rock profiles. Ophiolites might occur in back arc settings (smaller spreading centers that form from tensional stress near subduction zones where one plate overrides another). I did not know this – how exciting.
On a personal note, I must admit that I could not be a mariner. We have been in choppy waters for over a day now. Apparently it will get a little worse before it gets better (a couple of more days). I haven’t barfed yet, but I’ve come pretty darn close.
One advantage of feeling ill is being able to step outside for a bit. While observing the angry waters, I was able to photograph the appearance and disappearance of rainbows as the ocean waves hit the ship.
Perhaps tomorrow I will write about paleoceanography. However, the days have been packed with things to do. Today, for example, Mike Storm took us on a more detailed tour of parts of the ship that are typically inaccessible: the Captain’s bridge and the drilling platform. I was feeling very ill during this time, thus it was difficult to give my full attention. But it was amazing, and I did snap a few shots.