Processed to 3966 feet, moved more core boxes into storage

Today we boxed up 100 ft of rock core, to a depth of 3966 ft.  The drilling issues over the past few days appear to have been entirely rock-related, with clay-rich intervals greatly slowing down the rate of drill bit penetration.  Luckily, today the rocks contained less clay and drilling went more smoothly.  There was one four-foot interval that drilled extremely slowly, but the rest of the rock cut as quickly as before and produced the 100+ ft/day that we became accustomed to at the start of the HQ portion (below 2918 ft) of the hole.

After lunch, we moved 88 more logged boxes out of the rock lab and onto a pallet to be put into storage.  Tomorrow we should have time to move that same number of dry, unlogged boxes into the lab for later logging.  Finally, we'll move processed boxes onto racks to be dried.   

Processed to 3866 feet, drilled to 3916 feet; mahalo to special drill site visitors

Today we only had 33 more feet of rock core to box up, but the new bit is cutting a little better than the last one and drilling has progressed to 3916 ft as of this evening.  We were also able to log to a depth of 2137.4 ft, which is enough boxes to stack up another pallet of rocks to put into storage tomorrow.



A special mahalo to Senators Brian Schatz and  Mazie Hirono for visiting the drill site this week and showing your interest in and support for this project!

Processed to 3833 feet, drilled to 3866 feet

Something has slowed drilling progress, but we aren't quite sure yet what it is.  The drillers are getting excellent runs, but much more slowly than they should.  The only solution to this problem is to systematically investigate all the possible causes of the problem, and they haven't found that cause yet.  Tonight, the night shift will drill with a different style bit and see how the drilling rate changes.  If that doesn't help, they'll have to do a "wet trip," filling the drill string with water and checking it for cracks as they pull it out of the hole. 

Here on campus, in the morning we boxed rock core to a depth of 3833 ft, 40 ft deeper than yesterday.  In the afternoon, we logged to a depth of 2099 ft.  By the end of the day we started logging the most plagioclase-rich rock we've seen during the project.  If you'd like to get a look at this rock, click here and zoom in.

Processed to 3793 feet, drilled to 3833 feet

Today we boxed rock core to a depth of 3793 ft, 68 ft deeper than yesterday.  This evening's delivery of core extends down to 3833 ft, and the word from the drill site is that things are going a bit smoother now.  We were able to do a bit of logging and other logistics this afternoon, and although we're mostly under cover whether working inside or outside, the intense rain in the latter portion of the day made us happy to be working in the lab.

Processed to 3725 feet, drilled to 3754 feet

Today we boxed rock core to a depth of 3725 ft, 51.5 ft deeper than yesterday.  After the bit change, the drill crew has encountered a number of minor problems that have slowed down the drilling penetration rate.  In addition, some of the flows and intrusions are just more dense and take a little longer to cut through.  Overall, we're still making great progress.  A bit more core was delivered this evening, indicating that the drilling has advanced to at least 3754 ft below the surface. 

Here's a photo showing some interesting features we saw today:

The dark rock on the upper right is an intrusion.  Drilling only sampled the edge of it, but this intrusion appears to have baked the surrounding rock significantly.  All the olivine in the rock around the intrusion has been baked to black (click on the photo to see in greater detail).  In addition, there is a greenish clay(?) material that is partially filling the large, irregular vesicle located to the lower left of the intrusion.  This combination of features is just one of the many surprises we're seeing as the drilling continues to advance downward into the unknown.

Processed to 3673.5 feet, more intrusions

Today we boxed rock core to a depth of 3673.5 ft, 83.5 ft deeper than yesterday.  We saw more intrusions like those reported yesterday, among both pahoehoe and ʻaʻa flows.  The intrusions are generally denser and a bit more difficult to drill through than lava flows, which has slowed down the drilling penetration rate.  Additionally, the highly fractured nature of most of the rock has also led to some short (<10 ft) runs due to core barrel blockage.  The additional weight that must be exerted on the rock in order to cut through these intrusions also led to the end of our first HQ drill bit, the crew is currently tripping out pipe to replace the bit.  That bit lasted ~750 ft, which is a solid bit life when drilling through subaerial basalt.

Processed to 3590 feet, lots of intrusions

Today we boxed rock core to a depth of 3590 ft, 122 ft deeper than yesterday.  It was another day of excellent drilling progress, although the processing was more difficult due to the more fractured nature of today's core.  Nevertheless, the rocks were extremely interesting as usual - we saw lots of intrusions.  In fact, we saw at least two intrusions >10 ft in thickness, each with thinner intrusive offshoot arms above and below each main intrusion.  There were a number of striking intrusive contacts, like this one below:

Here an intrusion has invaded pahoehoe lava at a high angle, ~60°.  Some of the core showed nearly vertical intrusions next to the more vesicular lava.  A number of the intrusions had chilled, glassy rinds and had captured small clasts of rock from the flow units they had invaded.  Stay tuned to the blog for updates to see if this intrusive swarm persists as we drill deeper.       

Processed to 3468 feet, a new drilling record

Today we processed rock core to a depth of 3468 ft, 124 ft below the 3444 ft depth that we left off at yesterday.  The previous single-day drilling record for this project was 120 ft, the drilling crews managed to surpass that by just a few more feet.  My congratulations to both the day and night crews, each contributed equally to the achievement.  Although the HQ bit's smaller diameter cuts through the rock faster than the larger PQ bit, we're a lot deeper down the hole now than we were when the previous drilling record was set.  The rock itself also cooperated for a while, it was less fractured today than yesterday and easier to drill and process.  At the end of the day, we received another ~45 ft of core. 

Processed to 3344 feet, a partially filled fracture

Today we processed rock core to a depth of 3344 ft, 113 ft deeper than yesterday.  Processing was difficult because of how fractured the rocks were, some was too fractured to piece back together.  Below is an example of one of those fractures, but this one is more interesting than most:

This is a nearly vertical fracture that splits the core into two halves (one can see clear through the fracture in person, but the camera couldn't capture any light coming through the back side of the fracture).  Such features aren't rare, but this one is different because its top and bottom ends have been filled by clay and other weathering products.  We often see fractures that are open and others that have been filled, but this one shows both!  A partially open, partially filled fracture that you can literally see through is a unique sight so far for this project.  This feature supports my interpretation that fractures are commonly "healed" by groundwater flow and deposition of sediment through them.  Later compaction by subsequent flows and cementation by further alteration can make fractured rock more solid for our drilling.

Processed to 3231 feet, drilled to 3282.5

Today we processed 106 feet of rock core to a depth of 3231 ft.  We saw pahoehoe flows almost exclusively, and surprisingly little olivine in the rock units.  There were a number of baked flow contacts and compound pahoehoe units made up of multiple flows.  Tomorrow I'll be sure to post another photo of an interesting feature from the rock processing.

Drilling Update: At the end of the day the deepest rock delivered from the drill site was 3282.5 ft.  There are usually two deliveries of rock per day: The late-morning delivery is rock that the night crew drilled, while the evening delivery is the day crew's core that we process the following morning.

Processed to 3125 feet, a pair of contacts

Today we processed rock core to a depth of 3125 ft.  That's 119 ft of core since yesterday, which is just about the maximum amount we've processed in a single day during the project.  The HQ drilling is definitely going quickly!  During processing, we saw many of the features I've been mentioning lately in this blog: baked soil contacts, glassy margins between pahoehoe flows, elongate olivine, olivine settling within flows, clay filling fractures, slickensides or slickenfibres, etc.  Here are a couple of the contacts we saw today:

The contact on the left is something we're used to seeing; soil baked to orange when the overlying flow covered it (the underlying flow is in the next column of the core box and could not be included in the photo).  These kinds of contacts are obvious and easy to interpret.  The contact on the right shows no baked soil at all, but there is baking of the underlying rock to a reddish brown color.  That baking and the change in mineralogy across the coloration boundary define the contact.

Processed to 3006 feet, more core on the way

Today we went back to our core processing routine: We washed, dried, marked, and boxed 88 ft of rock core that was drilled yesterday and last night into this morning.  As of the time of this blog post, at least another 40 feet of core is on its way down the mountain for us to work on tomorrow morning.  This is HQ (2.625" diameter) core, so it is smaller and lighter and generally easier for us to work with.  It also can be drilled more rapidly because the smaller diameter means less rock to cut.  We expect to be very busy processing the core, but as the depth of the hole increases it will take longer to recover the core and send down an empty core tube, which will tend to balance out the faster rate of drilling. 

Logged to 2037.9 feet, a branching contact, our first 20 feet of HQ core

Today we logged core boxes to a depth of 2037.9 ft, 60.2 ft deeper than when we finished yesterday.  Here is a picture of one of the more interesting contacts that we examined (image is 16 x 9 cm):

As you can see, the baked soil at the top of the underlying unit has been invaded in roughly the viewer's direction by a toe of the flow that was emplaced on top.  As a result, this small toe cooled rapidly and has glassy margins.  The base of the overlying flow also cooled quickly and formed glass, along with abundant elongate olivine (click on the photo to see in more detail).

Drilling update: As of this evening, we have received our first 20 ft of HQ core.  Barring any major drilling issues, we expect to be busy processing this size core now for at least the next couple months. 

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"):