Friday, September 13, 2013

Finished logging, editing logs, preliminary sampling

Over the past few weeks we have continued to stay busy working on the rock core.  We finished logging at the end of August, and started right up on editing the logs for consistency and clarity.  So far, we have edited up to about Box 400 (~1670 feet). 
In addition to these activities, we also spent a couple days earlier this week taking preliminary samples from throughout much of the hole.  In the photo above there are 32 whole-rock samples made up of twenty aphyric rocks, seven intrusive units, and five picrites (>12% olivine).  The chemistry of these samples will be analyzed over the next couple months, and hopefully at least a few of them will be suitable for Ar-Ar dating as well.  The results of this preliminary work will then form the basis of further proposals to study the rocks in greater detail.

Thursday, August 22, 2013

Logged to 5484 feet, microscopic views of secondary minerals

Despite the lack of regular blog updates, we have been steadily logging the deepest core of the project over the last couple weeks.  At the end of today, we have logged to a depth of 5484 ft - only 302 ft to go!  The highly altered rocks contain a host of exotic zeolite minerals, see below for a couple pictures taken with our new microscope camera:
Both photos were taken at 40X magnification, and are probably different minerals of the zeolite family commonly formed by weathering of Hawaii basalts.  The upper photo shows a worm-shaped pattern of crystal growth that is unlike anything we've seen before, but there is very little of that material that is easy to extract.  We have gathered enough of the fibrous material in the lower photo that we can analyze in the near future via X-Ray Diffraction (XRD).  

Upcoming work to be done soon: Finishing the logging and editing all the logs for consistency, compiling a graphical log showing the stratigraphy of the hole, and sampling throughout the hole for preliminary analyses that will spur research proposal efforts.   

Tuesday, August 6, 2013

An important science visit

This past weekend was an eventful one for our project, we hosted a visit from a number of prestigious geologists who would like to study the recovered rocks.  Over the course of the weekend, our visitors reviewed many notable rock depth intervals from the drill hole.  They also discussed what the most urgent scientific questions might be that study of these rocks could answer.  I would like to thank these visitors again for making the trip and braving the dust, wind, and heavy lifting required to get a firsthand look at the rock samples.  Mahalo!
Above is a photo of our visitors and some of our crew posing with the drill rig.  From bottom left to right: Dr. Michael Garcia (UH Manoa), Rock & Data Manager Eric Haskins (UH Manoa), Dr. Nicole Lautze (UH Manoa), Dr. J. Michael Rhodes (UMass), and Principal Investigator Donald Thomas (UH Manoa).  Dr. Donald DePaolo (UC Berkeley) stands halfway up the stairs.  Top row from left to right: Core Processing Technician Brandon Jasper (UH Hilo), Core Processing Technician Meghann Decker (UH Hilo), Dr. Edward Stolper (CalTech), and Core Processing Technician Bryan Patterson (UH Hilo).  Photo courtesy of undergraduate Kaʻo Sutton (Carleton College).  PhDs are listed with their employing institution, graduates with their degree-granting institution.  Below is an image of most of these people reviewing and discussing some of the rock core boxes (Kaʻo Sutton second from right). 

Tuesday, July 30, 2013

Logged to 4900 feet, a full team of loggers today

Apologies for the long interval with no blog updates, we have continued to log core nearly every day since the last post.  The logging has been progressing a bit more slowly though, as alteration of the rock has made it more difficult to interpret.  We have currently logged to ~4900 ft, and are slowly but surely closing in on the final depth of 5786 ft. 
When we have a full team of four core loggers all working on the same day, we're able to get a lot of logging done.  Here from left to right - Bryan, Katie, Eric, and David are each logging consecutive boxes and generating a logging report or reports for the unit or units contained in their box.  The four loggers also discuss relationships among units that begin in one box and end in another, and help each other with interpreting the rock features.

Wednesday, July 10, 2013

Logged to 3901.6 feet, interpreting through a haze of alteration, complex flow/intrusion interaction

Despite the lack of blog updates lately, we have been busy logging box after box of core.  At ~3775 ft or so, the rock starts showing more alteration than above.  Some of the rock is so altered that little to no primary minerals are visible.  Vesicles are often partially or completely filled by clays and/or zeolites, and even the groundmass of the rock can be obscured by weathering products.  So far every unit contains enough decent rock for us to determine its basic features, though some of them are made more subtle by the overprint of alteration on the rock.  From boxing all this rock earlier, we know that the alteration will only increase with depth so we'll have to do the best we can to understand the rocks and how alteration has changed them. 
On a different note, the photo above is taken from one of our annotated core box logs.  Note the nearly vertical, complex interaction between units 216 & 217a (an aa flow and the dike that intrudes it, respectively) that persists for over five feet and extends into the next box where the interaction becomes too complex to trace!  The highly fractured fourth column of the box contains a mixture of aa and dike fragments that could not be pieced back together into their original orientation, thus the vertical contact line indicating the two units share this column.  There were a number of dikes near this depth interval in the core, but now that we've logged through this swarm of them there are only one or two more the rest of the way to the bottom of the hole.    

Sunday, June 30, 2013

Logged to 3261.7 feet, a pallet of core boxes ready for storage

When we finished logging yesterday, we had reached a depth of 3261.7 ft.  This is 134.1 ft in a single day, it certainly helps when you have four people logging!  Over the next couple months we'll have three people logging almost every day of the week, so we should have the preliminary logging of the first phase of drilling complete by the end of July.
After logging is complete, we stack, wrap, and strap the boxes on a pallet in this trailer so they can be brought up to the drill site and be put into storage.  This stack shows the last 48 of the PQ core boxes on top of the 30 shallowest HQ boxes.  My rough estimate of the weight of each pallet is ~3000 pounds (~1360 kg).

Friday, June 28, 2013

Logged to 3127.6 feet, 177 units

Today we logged core boxes to a depth of 3127.6 ft, 209.6 ft deeper than three days ago.  So far we have identified 177 lithologic units; from the expected pahoehoe, ʻaʻa, soil, ash, cinder and intrusions to surprising dune sands, sandstones, conglomerates, and glacial till deposits.  Soon we'll be stacking and wrapping up another pallet of rock boxes to put into storage, and logging some of the most complex intrusions recovered from the entire first phase of drilling.  I'll try and post a picture of one or both of these by early next week.       

Tuesday, June 25, 2013

Logged to the bottom of the PQ section, 2918 feet

Today our logging efforts took us to the bottom of the PQ portion of the hole (3.375" diameter), 2918 ft.  This is 332 ft deeper than the logging depth we reached a week ago.  The logging will happen more quickly now that we're focusing on it exclusively, and everything involving the HQ core (2.625" diameter) seems a little quicker and easier.  The core box on the left is the final PQ box, it contains pahoehoe with a dense flow interior (click on the picture for a larger view of the box).

Saturday, June 22, 2013

Processed to 5786 feet, the end of drilling Phase 1

Today we finished boxing up the 90 ft of core that was drilled yesterday.  This is the end of the first phase of HGRP drilling.  It's time for the drill crew to go on break, once they pack up all their equipment and leave the rig in good order.  Over the next couple months, we'll continue to log core down here at UH Hilo, and prepare for the next phase of drilling.  Blog updates will not be daily, but I will continue to update the blog regularly with project news.  We expect to have some scientists who are interested in studying the core visit us during this time, and some of the preliminary studies of the groundwater and rocks are about to begin.  

Thursday, June 20, 2013

Processed to 5696 feet, secondary mineral slickensides or slickenfibres

Today we boxed rock core to a depth of 5696 ft, 70 ft deeper than yesterday.  The drillers actually drilled 90 ft of core, but not all of it was brought down to us because of some of the activity related to wrapping up the drilling.  Tonight will be the end of the first phase of drilling this hole, I'll post the stopping depth tomorrow.  Meanwhile, here's another picture of a new and interesting feature we saw in the core today:
Here Bryan is holding a piece of core (diameter 2.625") that has green to white mineralizations on a fracture surface.  These minerals look just like the majority of the secondary material we're seeing in core vesicles and fractures, except that here they're striated in one direction.  Considering how much of this secondary mineralization we've seen in the deeper reaches of the hole, it's surprising that we haven't seen this kind of feature until today (when we saw two examples of this).  The composition of this material is certainly different from the slickensides/slickenfibres we saw shallower in the hole, but the process that formed all of them is probably the same.

Wednesday, June 19, 2013

Processed to 5626 feet, another sedimentary unit

Today we boxed up rock core to a depth of 5626 ft, 100 ft deeper than yesterday.  At this depth, if the rock drills well, this is about the maximum possible recovery in a single day. 
Above is a photo of another sedimentary unit, lately the drilling has recovered one interval of sedimentary rock each day.  This unit contains two large clasts in a finer-grained matrix at its top and middle portions, and then fine sediment at its base that shows bedding and cross bedding.  Note the presence of a variety of clast types in this unit, as well as green and white secondary materials. 

Tuesday, June 18, 2013

Processed to 5526 feet, logged to 2586 feet

A quick update on drilling and logging progress:  Today we boxed rock core to a depth of 5526 ft, 70 ft deeper than yesterday.  We saw more ʻaʻa today than usual, in fact it was the first time in a few days that we've seen ʻaʻa at all. 

Each day when we finish boxing up the newly drilled core, we head over to the rock lab and log the core's features into the database.  As of the time of this blog post, we've logged to a depth of 2586 ft; 86 ft deeper than a few days ago.  Soon the first hole of the project will be finished and we'll devote all of our workdays to completing the logging of all the rock recovered from that hole.

Monday, June 17, 2013

Processed to 5456 feet, more sediment

Today we boxed rock core to 5456 ft, 80 ft deeper than yesterday.  One of the really interesting sections of rock that we saw is the sediment shown in the photos below:


The photo on the left shows the entire interval of sediment (1.4 ft thick), while the photo on the right is a close-up view of the upper portion of this interval.  Note the bedding of the sediment, and the abundance of green (altered) material that is helping cement the sediment together.  The grain sizes of the sediments range from gravel to silt, but there is no particular gradation in sediment size with depth.  Also note that in the upper portion of this sediment interval there are pahoehoe flow fragments (center of right photo), which presumably were eroded from their original location and ended up in the body of water where the sediments were deposited.

Sunday, June 16, 2013

Processed to 5376 feet, extremely coherent rock

Today we boxed up another 100 ft of rock core, to a depth of 5376 ft.  Below is a picture of the rock that was drilled last night, which we processed this morning.  When fractures are this rare, the rock generally can be drilled more easily to produce full runs and it is also easier to process and interpret.
Note: Each tray is 6 ft in length, with the top ends painted.  There are pieces of circular foam at each end and a cover on each tray during transport.  Wooden blocks with the bottom depth of each run written on them are placed at the end of each run.  A full run is 10 feet in length.  With the foam and wood blocks and fractured rock, one run nearly or completely fills two trays.

Saturday, June 15, 2013

Processed to 5276 feet, logged to 2500 feet

Today we boxed rock core to a depth of 5276 ft, 70 ft deeper than yesterday.  The slightly lower amount of rock drilled was due to an upgrade of a few parts on the drill rig, which will help the crew save time in the long run. 

Down here at UH Hilo, less core means more time we spend logging.  We've now logged just past 2500 ft.  Sorry today is just another text update, I promise a picture tomorrow.

Friday, June 14, 2013

Processed to 5206 feet

Just a quick text update on the drilling progress: Today we processed another 80 ft to a depth of 5206 ft.  The drillers seem to have this recovery rate dialed in, hitting it on the dot nearly every day.  The bit they're using has lasted over 1000 ft so far, and could finish this hole.  Today was rainy and not great for pictures, tomorrow I'll try and post a photo of some of the interesting rock we've been seeing.

Thursday, June 13, 2013

Processed to 5126 feet, moved more boxes of rocks around

Just a quick update today on our progress.  This morning we boxed rock core to a depth of 5126 ft, 80 ft deeper than yesterday.  After that, it was time to move all the boxes we've logged out of the rock lab, onto a pallet, and into storage.  Finally, we filled the lab with new boxes to log and shifted other boxes into the drying area. 
Above, Mike uses the rock saw to cut a particularly long, unbroken piece of rock core into two-foot sections that will fit in the core box. 

Wednesday, June 12, 2013

Processed to 5046 feet, logged to 2444.3 feet, sandstone unit

Today we processed rock core to a depth of 5046 ft, 160 ft deeper than two days ago.  The drilling is in the home stretch of this first hole now, as we're fast approaching the 6000-6500 ft target depth.  At this rate, we could complete the first hole in 2-3 more weeks.  Each afternoon we continue to log the rocks, and by the end of today we've logged some interesting units to a depth of 2444.3 ft.  Below is a picture of the first sandstone unit we just recently logged (field of view is ~3 cm across)
This sandstone is made up of olivine grains (green), lithic fragments of basalt (black or gray), hematite (rusty orange), and a variety of other white to clear secondary minerals like calcite and zeolites produced by physical and chemical weathering of the original rock.  The sand has been compacted by the weight of over 2000 ft of rock resting on top of it, and weakly cemented together by secondary mineral growth.  The average grain size and degree of sorting indicate that this sand is fluvial in origin (deposited by a stream).  However, the angularity of the grains and lack of bedding indicate such a stream was probably ephemeral and may have washed the sand downslope to its final resting point in as little as one heavy rain event. 

Monday, June 10, 2013

Processed to 4886 feet, flaky green secondary mineralization

Today we boxed rock core to a depth of 4886 ft, 170 ft deeper than two days ago.  We saw one intrusion that was only a couple feet thick, and overall less secondary minerals than we've become used to seeing.  However, one fracture in particular showed quite a deposit (photo shows about eight inches from top to bottom):
At the time of the photo, this material was still wet and showed this striking green color.  When it dries however, it becomes a pale green and doesn't contrast as well with the surrounding rock.

Saturday, June 8, 2013

Processed to 4716 feet, logged to 2322.6 feet

Today we processed 80 more feet of rock core, to a depth of 4716 ft.  The rock continues to hold together extremely well, and the secondary minerals aren't causing as many problems with the drilling as before.  We also made significant progress logging this afternoon, interpreting rock units to a depth of 2322.6 ft.

Friday, June 7, 2013

Processed to 4636 feet, elongate black olivine and more secondary mineralizations in vesicles

Today we boxed rock core to a depth of 4636.0 ft, 150.5 ft deeper than two days ago.  The rock continues to hold together extremely well, making our job a bit easier.  Here are a couple images of the features we've been seeing lately in the core:






















Both images are of the same rock, the one on the left is core that has been dried while the one on the right is still wet.  The greenish hue of many of the secondary vesicle fillings is more evident in the wet core, while the elongate, black olivine is easier to see in the dry rock.  Note that the green material is concentrated toward the bottom of the vesicles, and it grades upward to white.  We have even seen layers of fill in some vesicles, with a sharp horizon mid-vesicle where the secondary mineralization changes from green to white material.  As for the elongate black olivine, we've been seeing extensive amounts of it throughout many units, so it isn't correlated with rapid cooling near unit contacts like the elongate olivine observed shallower in the hole.  I suspect that this olivine is black from the low-temperature alteration that is filling the vesicles, rather than the typical baking that can turn olivine black.

Wednesday, June 5, 2013

Processed to 4485.5 feet, a closeup of phillipsite

Today we boxed rock core to a depth of 4485.5 ft, 89.5 ft deeper than yesterday.  There was one intrusion among the units we processed, and lots of vesicles filled partially or entirely with secondary minerals.  Below is an example of a common zeolite mineral we've been seeing lining vesicles in the core, it's white and called phillipsite:
This image is only about one inch from top to bottom, and the phillipsite looks like small spheres lining the vesicles.  In fact, phillipsite does not make spheres at all, but rather many thin fibers grow radially outward from a central nucleation point.  This gives the impression of a sphere unless you use magnification to view the mineral or find a large enough sample to see the fibers with the naked eye.  Phillipsite and the other zeolites we're currently seeing in the core all incorporate water into their structure, indicating chemical interaction between the rock and groundwater caused the formation of these minerals.

Tuesday, June 4, 2013

Processed to 4396 feet, slow drilling rock

Today we boxed rock core to a depth of 4396 ft, 79 ft deeper than yesterday.  Some of the lava units that we've been seeing lately are particularly rich in secondary zeolite minerals and smectite clays.  At least one of these secondary alteration products has a soapy, slippery consistency that is making it difficult for the drill bit to bite into and cut the rock.  Drilling units rich in this material can take two to three times as long as those without.  Here is a picture of a typical one of these units:
Note that the unit is also rich in olivine (brown from alteration, with a bit of green unaltered olivine visible in the center of some grains if you click on the photo and view the larger version).  The core is quite unfractured, implying that the secondary vesicle fill may actually be adding strength and coherency to the rock.  Not all the lava units look like this, but these type of units are encountered nearly every drilling shift at some point.    

Monday, June 3, 2013

Processed to 4317 feet

Just a quick text update today to mention that we boxed rock core to a depth of 4317 ft, 101 ft deeper than yesterday.  We were able to finish that just after lunch, and logged core boxes for the rest of the afternoon.  Tomorrow I promise to post a picture of some of the interesting rock we've been seeing.

Sunday, June 2, 2013

Processed to 4216 feet, least fractured core of the project

Today we boxed rock core to a depth of 4216 ft, 250 ft deeper than the last blog post.  I haven't been able to update the blog until today, but we've continued to process and log core over the past few days.  I have some interesting photos of the rock to share, here are a couple taken earlier today:













Above are the core trays delivered late this morning, which are some of the least fractured runs of the entire project.  The third tray from the left contains an unbroken length of core that our 6'-tall manager stood next to for scale.  Stay tuned for further photo updates that show these rocks in greater detail.

Thursday, May 30, 2013

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.   

Wednesday, May 29, 2013

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!

Tuesday, May 28, 2013

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.

Monday, May 27, 2013

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.

Sunday, May 26, 2013

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.

Saturday, May 25, 2013

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.

Friday, May 24, 2013

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.       

Thursday, May 23, 2013

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. 

Wednesday, May 22, 2013

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.

Tuesday, May 21, 2013

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.

Monday, May 20, 2013

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.

Sunday, May 19, 2013

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. 

Saturday, May 18, 2013

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. 

Friday, May 17, 2013

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.

Wednesday, May 15, 2013

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.   

Monday, May 13, 2013

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.

Wednesday, May 8, 2013

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.

Monday, May 6, 2013

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.

Friday, May 3, 2013

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.

Wednesday, May 1, 2013

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"):
  

Tuesday, April 30, 2013

Logged to 1398.5 feet, learning more about fracture fill

We logged 95.1 ft of boxed rock core today, ending the day at a depth of 1398.5 ft.  Most of the day was spent logging, with a brief break to move boxes between the different buildings and areas we use.  We're starting to get to depths with a lot of "fracture fill," which interestingly remains a bit wet even after days in the drying area.  My current theory about this material is that it is water-absorbing clay produced by chemical interaction of the rock and volcanic glass with groundwater.  We hope to study this fracture fill material over the summer and figure out the details of its composition.  Here is a picture of what it looks like in a pahoehoe flow, filling multiple fractures in and around the vesicular lava:

Monday, April 29, 2013

Logged to 1303.4 feet

Today we had all three core loggers hard at work with no distractions, and we were able to log 129.8 ft of rock down to 1303.4 ft.  Most of the rock was pahoehoe, we only logged one ʻaʻa flow.  We hope to get a lot of logging done this week, all three core loggers will be working most days.  The only thing that will slow us down a bit is moving core boxes into and out of the drying area, the logging area, and the storage area. 

Sunday, April 28, 2013

Logged to 1173.6 feet, moving boxes around, drilled through the flank of a cinder cone!

Yesterday much of our day was spent moving core boxes from the rock lab to the armory, bringing new boxes to the lab to be logged, and bringing deeper boxes into the drying area.  As a result, we didn't get that much logging done until today.  We have now logged another 111.5 ft to a depth of 1173.6 ft, and we still haven't quite reached the base of that alternating pahoehoe/cinder sequence I mentioned in the last post.  Here's a representative image from our log reports of one of the box units within the sequence:
As you can see, this box unit contains the 31st and 32nd cinder fall deposits of the sequence.  At the depth shown in the photo, there are 32 mineralogically similar pahoehoe flows in the sequence as well.  I suspect we've drilled through the flank of a stratified cinder cone that may have almost constantly produced both lava flows and cinder fall deposits as it grew.  Thin, hot pahoehoe flows like the ones we've been logging are known to dominate the near-vent flanks of such cones.  From top to bottom, this sequence is ~190 ft thick and contains 40 cinder/pahoehoe intervals.  For comparison, the currently active Puʻu Oʻo cone on Kilauea's east rift zone had 44 eruptive episodes in only three years while building to its maximum summit height of 837 ft, and produced both lava flows and cinder fall deposits during this time.     

Friday, April 26, 2013

Logged to 1062.1 feet, an olivine cumulate xenolith

Today we logged rock core boxes to a depth of 1062.1 ft, 73.5 ft deeper than yesterday.  Interestingly, almost all of our logging was dedicated to a single unit that we still haven't found the base of yet.  This unit is a series of alternating cinder fall units and pahoehoe lava flows that all exhibit the same distinct mineralogy: moderately olivine plagioclase-phyric basalt (the mineral plagioclase is present as phenocrysts composing 3-10% of the rock, and plagioclase is always more abundant than olivine the olivine phenocrysts).  Hopefully tomorrow we'll finish logging this unit and by then we'll understand it better.
The photo above is a close-up shot of one of the pahoehoe flows from the unit we spent most of the day logging.  I think the photo shows a xenolith or grouping of olivine crystals that accumulated in the magma chamber just before eruption.  Olivine is a dense mineral that often accumulates along the bottom or sides of magma chambers, but we haven't seen a grouping like this but once before in the core.

Thursday, April 25, 2013

Logged to 988.6 feet, a piece of transitional core

Today we were able to log core boxes to a depth of 988.6 ft, 57.1 deeper than yesterday.  We encountered another transitional flow, and here is an illustrative example of how sudden the transition between pahoehoe and ʻaʻa can be in these types of flows:
The piece of core I'm holding in my hand shows a sharp transition from spongy pahoehoe to typical ʻaʻa with no associated process at all.  The transitional flow we logged today routinely switched back and forth between flow types without producing any contacts, while of course maintaining the same mineralogy throughout.

Once we finish logging this unit, the rocks only get trickier just below.  Stay tuned to see what we decipher tomorrow.

Wednesday, April 24, 2013

Logged to 931.5 feet, another tricky transitional unit

We were able to log core boxes to 931.5 ft today, 62.9 ft of material that was difficult to interpret.  After finishing logging an intrusion and sampling some glassy scoria, we ran into another unit that showed both characteristics of pahoehoe and ʻaʻa.  On top of that there was a lot of extra "cave-in" material due to rock falling in around the drill string at the time this core was recovered, so we had to proceed slowly and carefully while logging today.  Eventually we were able to determine the top, bottom, and internal boundaries of this transitional unit and get it logged.  Tomorrow's boxes contain rock that is quite different but also challenging to interpret for different reasons, stay tuned to hear what we manage to figure out about these rocks. 

Tuesday, April 23, 2013

Logged to 868.6 feet, first transitional unit

Today we were able to log core boxes to a depth of 868.6 ft, that's 125.6 ft logged in a single day.  Not bad since I was called away multiple times to help out with other duties.  Since we're doing so much logging, I thought I'd show you an example of the annotated photos that we're including in our log reports:
As you can see, there are two core boxes in each logging photo.  We add a distance and color scale on the left side of the photo, and label the top and bottom depths of rock shown in the photo in red.  Features are usually circled or pointed to and labeled in blue, and any contacts (none in this photo) are drawn with a thick blue line.  The purple dashed lines refer to internal boundaries within a unit (e.g. pahoehoe flow lobe boundaries that are formed when lobes with the same lithology are emplaced on top of each other during the same eruptive event).  The green box and "pc" inside show the location where a point count was taken to quantify the mineralogy and vesicularity of the rock unit.  The rock in the photo above is interesting because it has characteristics of both an ʻaʻa and a pahoehoe flow, this was the first unit we've logged where we had to call the flow type "transitional."  There is additional information about the rock in each photo in text form on the facing page of the photo in our final log reports.

Monday, April 22, 2013

Logged to 743 feet

Today we processed the final PQ run of core from the first hole, and switched our focus to primarily logging boxes of rock all day long.  Even starting late in the morning and stopping early in the afternoon to move boxes over from the armory, we logged about 70 ft.  I'll try and keep track of our logging progress each day, and periodically there should be new box photos added to that archive (see the Photos tab above).  We're seeing features for the second time now, and the rock is fully dry so interpreting it is a little easier.   

Sunday, April 21, 2013

2918 feet, casing the hole

Today we processed rock core to a depth of 2908 ft, and there should be one more run of rock arriving soon that will take us to 2918 ft.  Yesterday evening, it was decided that it was time to start casing the first half of this hole.  The drill crew spent all day today carefully lowering PQ casing (3.378" inner diameter) into the hole to protect and stabilize the sidewalls for when we drill even deeper.

After the casing is in place, the drillers will take a break while we continue to log the core boxes and Don Thomas samples the groundwater in the hole.  It's hard to say exactly how long this break will last, but it will be at least a couple weeks.  I'll continue to update the blog almost every day as we try to catch up on our backlog of rocks to describe.

When the drill crew returns, the plan is to cement the casing in place and continue coring with an HQ bit (2.625" inner diameter) to our goal depth of ~6000 ft.

Saturday, April 20, 2013

This rock is not what it appears to be

Today we processed 110 ft of rock core to a depth of 2868 ft.  As of the time of this post, our nightly delivery of rock is on its way but has not arrived yet.  I'll give a drilled depth update tomorrow, in the meantime here's something I've never seen before in any of the core I've looked at:
The photo above shows a single, unbroken piece of rock core.  In the center of the photo, what looks like a horizontal fracture is not a fracture at all.  Rock has been cut all the way around the core, but only to a shallow depth into the core cylinder.  I don't know exactly how such a cut could occur, but I'll ask our head driller tonight and find out.  My best guess is that a piece of rock got jammed between the cutting teeth of the bit, and rode in that position for a few revolutions around the core cylinder before the stuck rock piece broke, came loose, or wore away.  However it happened, this is a rare occurrence when drilling and I can't imagine any natural process that would produce this effect.

Friday, April 19, 2013

2808 feet, a rapid contrast in rock type

Today we processed rock core to a depth of 2758 ft, and received more at the end of the day that stretched down to 2808 ft.
The image above shows about 1.5 ft of rock from two consecutive trays that make up a single run of core.  The tray on the left has loose, baked soil and broken fragments of ʻaʻa clinker.  The tray on the right contains the massive interior of the same ʻaʻa flow.  Within this 10-foot run, the recovered core changes from some of the least cohesive material we have drilled to some of the most cohesive over only a few feet of depth.  This illustrates a challenge of drilling through a basaltic shield volcano: Although the rock can be drilled relatively easily, there are many abrupt changes in cohesion and internal resistance to stress that require the driller to make rapid adjustments in order to keep drilling smoothly.

Thursday, April 18, 2013

2698 feet

Today we processed rock core to a depth of 2658 ft, and received newly drilled material from as deep as 2698 ft.  We saw many interesting features, from baked soil at flow contacts to slickensides/slickenfibres to delicate flow surface textures.  I wanted to take a picture of the latter, but got distracted by the multitude of other tasks that had to be completed.  Hopefully I'll have a chance to get a few good pictures for this blog tomorrow.

Tuesday, April 16, 2013

2548 feet, and a high-angle baked contact

Today we processed rock core to 2548 ft, 80 ft deeper than what we processed yesterday.  The drill crew had to trip out and dislodge a loose piece of rock that fell into the hole, so we didn't get a delivery of core this evening.  Here's another of the pictures we've been taking of the core:
This is an end view of a cylinder of rock core.  The brown region is a layer of baked soil, while the darker part is lava rock.  We rarely get to see views like this because fractures usually don't cut straight through adjacent materials with such different properties.  The image shows that the lava flowed over the soil  at a significantly high angle, probably on a slope - otherwise the soil would have been laid down horizontally and a fracture of this orientation would show no lava rock at all from this view.   
 

Monday, April 15, 2013

Over 2500 feet, a new recovery record for the project, and weathered sand

Today we processed rock core to a depth of 2468 ft, and the rock delivered at the end of the day carried us over the 2500 ft mark.  The drilling has been going so well lately that the past 24 hours produced a new record of 120 ft recovered in a single day! 
Above is a picture of some interesting sand that was recovered recently.  We have seen a couple intervals of loose, black sand but this sand is lighter and more coherent (it will still crumble if you aren't careful handling it!).  My hypothesis is that low-temperature chemical alteration and growth of secondary minerals within this sand has both lightened its color and cemented it together somewhat.  Perhaps deeper in the hole we will find sand that has been compacted and cemented enough to call it sandstone.   


 

Sunday, April 14, 2013

2400 feet, intrusion alteration patterns

Today we processed rock core to a depth of 2348 ft, and our end-of-day delivery contained rock to 2400 ft.  It was a busy day for sure processing over 110 feet, but the core is starting to hold together a little bit better and that makes it a little easier on us.  As promised, here are some pictures of interesting features we're seeing in the rocks:



















The photo on the left shows an intrusive contact with an olivine-rich lava flow on top and a fracture surface of the intrusion exposed below the contact.  The photo on the right shows the bottom contact of that same intrusion over that same lava flow, with a different fracture surface exposed again.  The psychedelic colors you see are probably all within the smectite clay mineral family, formed by low-temperature alteration of the intrusive rock as it was chemically weathered by groundwater.  This four-foot-thick unit is the first intrusion we've seen for hundreds of feet, but it was well worth the wait!

Saturday, April 13, 2013

2268 feet, photos of drill site activities

Today we processed core to a depth of 2238 ft, and received a shipment of rock at the end of the day that reached 2268 ft.  We saw mostly ʻaʻa flows today, which is surprising since this hole has been dominated by pahoehoe so far.  Over the next few days we'll see if that is just coincidence or the start of a trend.  Close-up pictures of the rock will have to wait until tomorrow, CSAV Educational Specialist Darcy Bevens provided us with some great photos of activity up at the drill site today:
Above, Donnie (left) and Nainoa (right) extract core from the barrel into the trays.  The darker material next to Donnie's hammer is the rock itself, the lighter material is the end of the core barrel.  Donnie slides the rock out and into the tray while Nainoa makes sure that the core pieces fill the tray completely and are arranged in the proper vertical orientation (top side up).
Head Driller Ron Fierbach (left) and Principal Investigator Don Thomas (right) examine and discuss the newly extracted run of core. 

Friday, April 12, 2013

Over 2200 feet and another interesting contact

Today we processed rock core to a depth of 2158 ft, and this evening's delivery of core runs just beyond 2200 ft.  We saw some interesting features in the rock for sure, hopefully I'll be able to take photos of those features soon...but first, here's another example of an intriguing baked soil contact between pahoehoe flows:
Note that the clasts within the baked region are angular, have diverse lithologies, show no particular sorting with depth, and do not resemble the lava rock above or below.  I can also inform you that the baked region is quite solid and cohesive, probably the result of being welded together by baking and/or compaction by all the feet of rock that was recently on top of it.  One possible origin for this layer of conglomerate is glacial outwash, though as I mentioned yesterday we can't be sure of that without knowing more information.  I'm currently reading up on the glacial history of Mauna Kea to better understand and interpret features like this.    

Thursday, April 11, 2013

Baked soil contacts

Today we processed core to a depth of 2083.6 ft.  We are seeing more contacts between units marked by baked soil layers, the picture below is an example:
This is an ʻaʻa flow on top of a pahoehoe flow.  Between them is a layer of soil that was baked and oxidized to a rusty orange color when the ʻaʻa flowed over it.  In this case there are angular clasts of rock and large sediments in the contact area, which don't look like weathering products of the pahoehoe flow.  One possible explanation for them is that they are products of glacial erosion that washed down the paleo-slope of the volcano.  There is extensive evidence of glaciation on Mauna Kea dating back as far as 180,000 years ago, so if the rocks we're currently drilling are younger than the oldest glaciation, we could see glacial deposits in the core.