Unusual Rocks at Mauna Kea

A recent post by Callan Bentley at NOVA Geoblog got me thinking back to a couple long-ago field trips on the Big Island of Hawaii, back during the 1987 GSA Cordilleran section meeting. One of the trips we took was to the top of Mauna Kea, where, after a visit to the W. M. Keck Observatory, we walked down from the peak elevation of 4205 m (13,796 feet) to some elevation quite a bit lower than that, through miles and piles of unusual volcanic rocks of basaltic to andesitic composition. Well, the truth is, I don't really remember exactly how far we walked, but we dropped at least 3000 feet in elevation, and that was pretty difficult for some. A couple people had to bail just below Lake Waiau, because of the altitude. And because I have zero photos of that long-ago field trip (unless a few are left up in Alaska somewhere), go see Callan's photos of his trip to Mauna Kea!

What I found by doing a little online research, was that the unusual (or "weird" - I think I said) volcanic rocks on Mauna Kea are 1) the Hamakua Volcanics, composed of basaltic rocks called picrites, ankaramites, and alkalic and tholeiitic basalts, and 2) the Laupahoehoe Volcanics, composed of hawaiites, mugearites, and benmoreites (Kennedy et al, 1991 and Wolfe et al, 1997 - see below). Not all the rock types above, like picrites, are unusual to Mauna Kea; some can be found on the younger volcanoes of Hawaii.

Mauna Kea is essentially a late-stage basaltic shield volcano, which is what Mauna Loa and Kilauea (along with Pu'u O'o) will eventually grow up to be when they get older. Mauna Kea's end stage Hamakua and Laupahoehoe Volcanics essentially indicate that Mauna Kea is just about done, and is in the post-shield stage of its evolution, although it is still considered dormant rather than extinct, and more eruptions of the end-stage basaltic to andesitic flows would not be unheard of nor totally unexpected (Hawaii CVO site).

As for what these strange or unusual mostly basaltic rocks are, here is the best description I could find, and it approximates what I remember, though may not be 100% precise:

Basalt with extra Na+K = Hawaiite
Basaltic andesite with extra Na+K = Mugearite
Andesite with extra Na+K = Benmoreite
Dacite with extra Na+K = Trachyte
Mugearite or Benmoreite with LOTS of extra Na+K = Phonolite

A Few References and Links:

Kennedy, A. K., Kwon, S.-T., Frey, F. A., West, H. B., 1991, The isotopic composition of postshield lavas from Mauna Kea volcano, Hawaii: Earth and Planetary Science Letters, Volume 103, Issue 1-4, p. 339-353. [Abstract here.]

Wolfe, E. W., Wise, W. S., Dalrymple, G. B., 1997, The geology and petrology of Mauna Kea Volcano, Hawaii; a study of postshield volcanism: U.S. Geol. Survey Prof. Paper 1557, 129 p. [Abstract here.]

On Climbing Mauna Kea
On the Geochemistry of Hawaii Volcanic Rocks
On the Laupahoehoe Volcanics
Wikipedia on Mauna Kea

Volcanoes Accused of Evil Intent

Talk about anthropomorphism, volcanoes have now been labeled as evil by a certain non-geo blogger. Twice!

Bloggers of the geoblogosphere - Maria, The Volcanism Blog, and Chris Rowan - have come to the defense of the otherwise defenseless volcanoes of the world. After all, someone's gotta do it. Who's ever heard of a volcano hiring a lawyer? No need for that, though: we've got the geoblogosphere to the rescue!

It's all a question of balance, though. Without volcanoes, we would have no life. Without life we would have no extinctions. Without life, we would have no humans to bitch about volcanoes and extinctions. On and on, yada yada yada...

All I can say is:
Volcanoes of the World Unite! Don't put up with all this maligning of your no doubt pure intent!

A New Geologist Survivor TV Show

Well, not really.... There is, once again, an email going around to various geological types (this is the second time I've seen it) which refers to Uncyclopedia's take on Geologists. The email circulating now, describes a 'geologist survivor-type' show, supposedly being considered by CBS in 2008 (reality TV?).

They were successful in finding nine geologists, 6 males and three females, between 25 and 50 years of age, and they quickly set up the first challenge; researching an active volcano in the Phillipines. The geologists and camera crew set up camp near the bottom of the volcano. The camera crew filmed the nine geologists bonding. The geologists were supplied with alchohol (a common strategy to loosen up the cast in reality TV), but the camera crew was surprised to notice that even after drinking gallons of the liquid, the geologists did not change their behavior, and continued talking in an obscure jargonized language about 'bombs', 'breccia,' and 'lahars,' none of which made for good reality TV.

Does the above sound at all familiar? I'm reminded of certain Death-Defying Geologists and their lava photos! The reality-TV-type testing goes on, with the geologists just not being able to leave or be voted off the show.

Finally, few of the scientists [geologists] seemed to understand the concept of 'voting off' another member. After consulting a nearby university, the crew finally explained that the geologists were 'competing for a GSA research grant.' This didn't go well either, as the geologists pointed out that they didn't have the time to write a research paper. Finally, they were simply told to get rid of someone on some sort of criteria. After a council, the geologists decided that whoever had the worst aim with a rock hammer would be told to leave.

Congratulations to certain geoblogosherians who have recently completed such research-type papers (and sorry if I've left some of us out!). As you can see above, geologists are simply not well suited to reality TV, since they (we) have their own way of doing things. The second event that is designed to get rid of some geologists takes place in Alaska.

The second event, landing in a bush plane in upper Alaska, was a complete failure. None of the geologists were nervous at the idea, which destroyed the drama the crew was hoping for, and worse yet, no-one in the production crew was willing to accompany the geologists to the site, out of sheer terror. The result was that small cameras were given to two of the geologists to film themselves. When the footage and geologists returned, the editors found tapes filled with footage and commentary about mountains and 'glacial erratics'. Only ten percent of the footage featured humans, and most of that footage was simply the petrologist standing by outcrops for scale.

By the time the production reached Hawaii, most of the camera-crew had quit (because of the steady diet of chili and the dangerous situations), and only five of the geologists were left; not because they had been voted off, but because they had been over-excited by rock formations at various locations and had refused to leave. Moreover, paying for an almost-constant supply of beer and transportation of the geologists' luggage (which mainly consisted of rock samples and unmentionably dilapidated field clothing), had almost exhausted the budget. CBS finally pulled the plug on the project in January of 2008, despite their fear that they might be sued for withdrawing the promise of a prize; however, none of the geologists sued, as they were still under the impression that they needed to publish a research paper to receive the money.

As you can see, geologists are simply not suited for reality shows, living as they (we) do in their (our) own reality. The rest of the article entitled "Geologist" is also interesting (although some parts are more humorous than other parts), and it includes a section about "Geologists in the Movies." Sound familiar? And more:

How to spot a Geologist
To spot a geologist in the wild, look for:

• Hand-lens, compass, pen-knife, handcuffs etc. tied round neck with string. ...
• When helping someone move and you ask "is this box full of rocks?" They answer "yes, be careful."

If you remain unsure, ask the subject to draw an annotated diagram of a trilobite. A true geologist will immediately reach for their waterproof notebook - this is your opportunity for escape.

And so it goes...

UPDATE: This part of the Unclyclopedia article on geologists has apparently now made it into hard print - see Highly Allochthonous for links.

Questions in The Night

Ah, the smell of coffee in the morning...

Well, I'm up early, and it's still dark outside, because we have been under the domain of Daily Time for a couple weeks, now. The sunrise above, is what it might look like here in an hour or more.

Getting up early sometimes leads me to wondering perennially stupid questions, at least if I'm not woken up by work worries or other things, which is fortunately not usually the case, unless I'm overly concerned about drill rigs or things like that. Questions:

• How large will the Basin and Range and Intermountain West become in the next 10 to 50 million years?


• Is the entire Basin and Range underplated by core complexes that we simply haven't seen yet (because they are presently too deep to see)?


• Will the ocean move into the rifted Intermountain West before Las Vegas or Los Angeles can steal northern Nevada's groundwater?


• Will we discover a "Walker Lane of the East" somewhere, somehow bounding the eastern part of the Great Basin the way the Walker Lane more or less bounds the western part?


• Will the mantle (or "Serpentosphere"??) ever be proven to be a source of methane? And will we tap it for energy by drilling deep into the San Andreas fault?
  
• Will we survive the next 300 years of natural and user-enhanced global warming (according to Milankovitch cycles, much pooh-poohed by many geologists, we will reach a temperature peak naturally in about 300 years, and in fact are already over the main temperature hump toward a long cooling trend)?


• And what will our slide into the next ice age bring in the years following that upcoming peak be like (provided, of course that we don't change all that)?
  
• Will Yellowstone erupt sometime within the next 500,000 to 1,000,000 years (or Any Day Now), thereby putting an immediate halt to any current man-made and natural global warming?


• Will geologists discover a gold deposit in the present locality of the Mendocino Triple Junction in 1 to 3 million years, which would be similar to the McLaughlin gold deposit near Clear Lake, CA , which formed within a couple million years of the triple junction passing through that area?
  

These are the things that wake geologists up in the middle of the night! Stay tuned to find out the answers, if any are forthcoming.