Logged to 1977.7 feet, new core soon

Logging Update: We logged core boxes to a depth of 1977.7 ft today, 93.3 ft deeper than the last blog update.  Although we examined and interpreted many interesting features in the core today, none of them caught my eye as particularly photogenic.  I'll try and post a photo tomorrow.

Drilling Update:  The drillers are still cleaning out the last of the cement left in the drill pipe from cementing the bottom of the casing in place; they expect to be drilling again soon.

Logged to 1884.4 feet, drilling to start up again tomorrow

By the end of today we logged to a depth of 1884.4 ft, 78.7 ft deeper than at the time of the last blog post.  For perhaps the first time in the logging, we recorded more than two consecutive ʻaʻa flows.  Such an observation is significant because it really shows how dominant pahoehoe is in the region beneath the drill site.  I hope to share data soon on both the number and overall thickness of pahoehoe vs. ʻaʻa units.

As of this afternoon, the casing cement job is complete and the cement inside the casing has been drilled out.  The drill crew is ready to advance downward with the HQ-sized bit to a goal depth of over 6000 ft.  We will commence 24/7 drilling operations tomorrow.   

Logged to 1805.7 feet, and a stark change in mineral content at a contact

By the end of today we logged to a depth of 1805.7 ft, 108.5 ft deeper than the last blog update.   The drillers are getting ready to cement the PQ (3.375" inner diameter) casing in place tomorrow, and hopefully we will start drilling the HQ (2.625" inner diameter) portion of the hole later this week.  In the meantime, I'll keep showing you some of the interesting features we've seen while logging:

Here is a close-up of a contact between two pahoehoe flows.  On the top and right you can see the rock is olivine-rich (the greenish minerals), while the rock on the left and below is rich in plagioclase feldspar (white, thin and elongate blades).  There is some soil formed by weathering and erosion at the top of the plagioclase-rich underlying unit, and a thin layer of glass at the interface between flows that has been somewhat altered to yellow palagonite.  The dimensions of the picture are 6 x 4.5 cm.

Logged to 1697.2 feet

Over the past two days we've put another pallet of core boxes into storage, and logged another 88.2 ft to a depth of 1697.2 ft.  I don't have any particularly new photos to post today, we've continued to log a lot of pahoehoe flows with clay fracture fill and elongate olivine lately.  Looking ahead, tomorrow we'll be logging a few consecutive ʻaʻa flows with strongly baked and weathered clinker intervals between them.  I'm sure there will be something photogenic and new within those units that I can share.

Logged to 1609 feet, elongate olivine

After our first weekend off since the start of the project, we were refreshed and ready to log more rocks this morning.  After moving some core boxes into the different work areas, we logged 60.4 ft today to a depth of 1609 ft.  One of the interesting things we saw while logging today was the presence of elongate olivine crystals:

We have seen elongate olivine before, but today I saw one that was 5 mm long and barely the width of a hair.  These crystals are known to form during rapid cooling and/or crystal growth, and that fits with where we've been seeing them: At the margins of olivine-rich pahoehoe flow lobes where cooling can be rapid enough to form volcanic glass.

Logged to 1548.6 feet, glassy pahoehoe toe

Over the last two days we logged 81.9 ft of core boxes to a depth of 1548.6 ft.  We are also in the process of moving logged core boxes into storage, and arranging for some preliminary chemical analyses of a few flow units from (mostly) the upper portion of the hole.

Below is the glassy toe of a pahoehoe flow lobe, measuring ~5 cm across:

 Although some of the glass has been altered, this lobe contains plenty of fresh glass as well.  We haven't seen all that much fresh glass among the flows in this hole, but when we see it we take small samples of the glass for future analysis.

Logged to 1466.7 feet, finally some ʻaʻa and intrusions

We logged 68.2 ft of core boxes today, to a depth of 1466.7 ft.  This means we have logged just over half of the 2918 ft of core that has been drilled so far.  Over the next couple weeks hopefully we will come close to getting it all logged before drilling starts up again.

After ~200 ft of pahoehoe flow units, we got to log an intrusion today, and there is an ʻaʻa flow not far below that we'll log tomorrow morning.  In honor of the thick pahoehoe interval we logged, here is a picture of a tasty-looking smooth pahoehoe texture (core diameter is 3.375"):