Sorry to have been quiet for a bit – but it’s been kinda hectic here!
Activities at our first site, U1559, were cut short by very resistant volcanic rock and the premature (?) destruction of our RCB (Rotary Core Barrel) drillbit. We then moved to Site U1558, where despite some bouncy weather to start, things went a lot better – a successful sediment hole (which meant some serious heavy lifting in Geochemistry, as we have to maneuver heavy titanium squeezers in and out of Carver presses, where they were squeezed at up to 25000 psi to extract interstitial water), followed by over 200 meters of coring through ocean crust basalts with (for basalts) very high recovery (in the 60% range!).
We’re done with all the shipboard analytical work on these two Sites except for the rock chemical analyses, which are agonizingly slow to complete (from the core to a complete ICP-AES measurement can take 7-9 days – why this is so will be a Geek Blog entry). Right now, we’re at our brand-new site, U1583 (we’re the first to visit here to drill!). We’ve drilled a sediment hole (and collected more waters) and we’re currently dropping pipe to start a deep hole that will penetrate through to the basalts. These basalts will be younger (30 Ma), compared to the U1558 ones (49.1 Ma), but older than the U1559 ones (6.6 Ma), so it will be interesting to see how these look by comparison.
On our way to the basalts at Site 1583 we’ve had a few misadventures – specifically a shear-away pin stuck in the core barrel 4200+ meters below us, which hung up retracting the corer and required them to slowly pull up pipe for a full day before they could loosen it and get back to business. It was a reminder to me of how extreme and delicate what we’re doing really is, a sensibility that gets lost maybe too easily seeing how well the crew and the drillers go about doing what they do.
Hopefully by tomorrow we’ll have new calls of Core on Deck and some truly, absolutely new rocks to look at, that no one has ever seen before!