Looking For Detachment

Evelyn Mervine at Georneys is holding another Accretionary Wedge carnival (two in a row!), this time it's AW #58: Signs! I was first thinking of some geographic signs along the lines of her original signposts meme, and realized the ones I was thinking of consist of license plates rather than mileage signposts, and that all the ones I have are probably non-digital and currently a bit hard to reach (nevertheless will try to post some when I'm not quite so busy). Instead, I dug up a sign from a trip to Crater Lake a few years back.
Hard to say whether this sign on a very steep part of the west rim of Crater Lake is to warn one away from the danger of the steep slope, or a warning that the mountain (cinder cone or entire caldera?) might blow!

Glacial grooves and striations, field sandal for scale.

Either way, if one persists past the sign in true geological fashion, one will find a great exposure of glacially striated and grooved volcanic rock. Read a little more about the glacial history of Crater Lake here.

This traveling meme was started by Alice at Sciencewomen, passed to Magma Cum Laude, then to NOVA Geoblog, and on to Geotripper Part 1 and Part 2, and then on to Geology Happens.

January: The famous (or infamous?) International Hotel in Austin, Nevada. This is currently the last recorded visit to this establishment. The beer is okay.
I don't recommend the food.UPDATE 17Jan10: The food on Christmas day was excellent!
February: Great Basin National Park and environs twice (and at least one trip through central Nevada).
March: Alaska, for the Iditarod and beers (and more than two trips through central Nevada).
April: Middlegate Station, Nevada - a good place to eat, has above average beer, and you can have wi-fi in your room. The Carlin Canyon Unconformity (or fault, depending on who you talk to) - and at least two trips through central Nevada.
May: Titus Canyon - the largest breccia fragments are truck sized. Death Valley. The Mojave Desert - granite at Teutonia Peak, part of Cima Dome. Some mines and properties in western Nevada as part of the GSN spring field trip (and two or three trips across central Nevada, depending on how you define "central.").
June: Wheeler Peak in springtime (would you believe late winter?).
July: Back to Wheeler Peak, more than once, where it was looking like spring. San Francisco, where I didn't get pictures of any famous bridges but did have some good beer. (Also in July, at least two trips through central Nevada.)
August: I made one short trip and completed most of a second trip to Caliente, Nevada, and environs (and made two trips through central Nevada).
September: Reno - that's Slide Mountain on the left and Mt. Rose on the right. Our lake house (we have to drive for this view). Lassen Volcanic National Park. (And two drives through central Nevada.)
October: I went to Crater Lake and other points north on the way to the GSA meeting in Portland. Then, after going here and there, I went to Jarbidge, Nevada, a first for me. (And made only one trip through central NV.)
November: I hiked in the southern Egan Range, where I had a great view of Wheeler Peak. Later in the month, I went to Reno for a GSN meeting, but took zero photos. (Drove across central Nevada twice.)
December: I went to Reno for the NWMA convention, where I once again took zero photos. I drove to our lake house and drove back through snow. I've been across central Nevada twice so far this month and don't have any big plans for the rest of the month. I've taken care of business, shoveled snow, and watched birds at our little house in eastern Nevada.

I'm doing the usual year-end meme - like I did last year - which is from Biochem Belle, DrugMonkey, Short Geologist, and Lockwood. The meme consists of posting the first sentence of the first blog post of each month of the year, with the link to that post. I've done that - with a couple minor modifications - along with the photo belonging to that post. I skipped two CotA links, which were the first posts of several months, I skipped one Two-Years-Ago post, and one Road Song post. As Lockwood pointed out, the geoblogosphere usually messes with the rules of any given meme, so I'm just being "normal" - for a geo-type. Unlike Lockwood, I didn't post any titles.

January: Here's a Happy 2009 to everyone, with a photo of the last sunset of last year, 2008.

February: The first ever Carnival of the Arid is up, hosted by Chris Clarke of Coyote Crossing.

March: For this month's Where in the West, we have the above [below] famous mountain, a mountain that has more than one name.

April: The third Carnival of the Arid (CotA#3) is up, over at Coyote Crossing.

May: aboutgeology: @sfoxx OK, why is the Eureka Qtzite such a familiar name? What's it signify? 7:02 PM

June: I haven't done a Where in the West since March, so no doubt everyone's forgotten all about it!

July: Once again, I have a few field photos from Great Basin National Park - this time of alluvial fans as seen looking down from about 12,000 feet on the shoulder of Wheeler Peak.

August: It's time for Where in the West again! For the August 2009 version of WITW, we have the above [below] unknown area located somewhere in the west - that would be somewhere in the western part of North America.

September: I just got back from a short trip to Caliente, Nevada. The weather was looking good when I headed down there, with temperatures predicted to be slightly lower than average, especially if clouds like these stayed around.

October: Just the other day, Monday to be precise, I was walking around above town thinking about the signs of fall that were all around: dry, straw-colored bunch grass (unknown variety), yellow blooms of rabbitbrush (right foreground), golden-brown blooms of sagebrush (left middleground), and yellow to bright red aspen on the distant mountain.

November: After making the unexpected turn onto Oregon Highway 62, I drove toward Crater Lake and stopped at the first pullout, the entrance to the Ponderosa picnic area (Google Maps location) - named, no doubt, for the magnificent Ponderosa pine trees that dominate the area.

December: I'll be at the Northwest Mining Association meeting in Reno for a few day (NWMA), which isn't to say I absolutely won't blog, but... in case I don't, I'm posting a few ways to find this blog.

[There hasn't been a first photo in December, yet, other than the one at the top of this post. It would be rather circular if I reposted it here, so I won't.]

Moving on with my road trip up to last month's GSA meeting in Portland, my next stop past Annie Creek was Crater Lake itself. The east and south parts of the rim road were closed, but the exit out the north was open (currently all but the entrance from the south to the Rim Visitor Center are closed). I haven't been on the north exit/entrance to the park for a long time, and the sidetrip off Highway 97 added only a few extra miles (although also a couple extra hours!). The gray photo is from the Crater Lake webcam earlier this morning - normally you can see across the lake from this location.

The first five photos were taken from three stops here, which are all very close together on the West Rim Drive.
This is a fairly standard photo of Crater Lake, with Wizard Island in the west part of the lake, and Llao Rock on the crater rim beyond. Wizard Island, an andesitic cinder cone, formed about 7,200 years ago (Bacon, 2008 and Cranson, 2001/2002).
Llao Rock, the massive cliff on the crater rim behind Wizard Island, is a rhyodacitic dome, with a flow beneath the clouds to the right, that erupted about 200 years before the climactic eruption of Mt. Mazama. The whitish layer beneath Llao rock is an air-fall ash and pumice layer from an eruption just prior to formation of Llao Rock. That explosive eruption about 200 years prior to the climactic eruption produced a widespread ash bed found in northern Washington, southeastern Oregon, and western Nevada, where it was called the Tsoyawata Bed by J. O. Davis before it had been correlated back to its source at Crater Lake (Davis, 1977; Davis, 1978; Bacon, 1983; Davis, 1985).
As usual, the water of Crater Lake was exceptionally blue.
If you make it to Crater Lake when most of the roads are open, be sure to take the boat tour out to Wizard Island (the hike down - and then back up - the crater rim to the Cleetwood Cove boat dock is steep and rocky). After landing at Wizard Island, you can climb the cone to the top, where the trees are fascinating, and where you can also see the cinder cone crater. Then you can get a later boat back to the Cleetwood Trail.
This photo looks across the lake at the west side of Wizard Island, where an andesitic flow reaches toward the west crater wall. The Devil's Backbone can be seen across the flow on the rim beyond, just right of the low mass of trees. This is an andesite dike - the andesite of Devil's Backbone - going up the crater wall (enlarge photo - the upper part of the dike appears to be in shadow). The dike cut through the older rocks about 4,000 to 5,000 years ago (Bacon, 2008).
At stop three (centered here on Google Maps), I looked across the lake toward Cloudcap, which is mostly in the clouds, and I noticed something a ways to the left of it, on the crater wall.
That something can barely be see in this photo, between the trees on the far side of the lake.
Here it is, enlarged a bit, a light-colored line on the opposite crater wall.
It's the Wineglass, after which the Wineglass Tuff was named! Enlarge the photo, and you'll see that the Wineglass is a wineglass-shaped talus slope beneath a layer of Wineglass Tuff (aka Wineglass Welded Tuff of Williams, 1942). Just to the left of the Wineglass is a prominent cliff called The Pallisades, formed by the andesite of Roundtop, which has a K-Ar age of 159±13 ka (Bacon, 2008).
Okay, now I've moved on to stop 4: "Danger Will Robinson!" - and what geologist could resist going beyond this sign? (Another photo of the lake and Wizard Island, ho hum.)
Instead of obeying the sign, I followed my geological instincts to this cliff edge, where I found some great glacial striations and grooves on some lava rock (possibly the andesite of Applegate Peak, which has a K-Ar date of 258±8 ka to the south - Bacon, 2008). The grooves point approximately toward the Wineglass - a northeasterly direction.
Here's an enlargement of the grooves and striations, with a field sandal for scale. It looks to me like the ice was moving to the southwest (lower right in the photo), but I didn't examine the outcrop in detail while there.
The nature of the day was apparent at the Watchman Overlook, where many were standing around waiting for the mist to clear.
The mist came and went, ebbing and flowing, finally clearing for a clear view of Wizard Island. You can see the crater of the cinder cone in this photo, along with an andesitic flow that erupted from vents near the base of the cone. The flow comes almost to the edge of the lake at the Watchman Overlook.
While watching the mist come and go, I took a few photos toward Llao Rock, and just happened to get a bit of the Devil's Backbone in the picture, just beyond the dark foreground mass, in the mist near the water's edge.
Here you can see the lower part of the Devil's Backbone dike, beyond that darkly shadowed mass of rock in the foreground. Beyond that, you can see Llao Rock and the white ash layer below it from a different angle, through the mist. The dark rock in the foreground is part of the andesite of the west wall, which has a K-Ar age of 70±4 ka (Bacon, 2008).
This is the andesitic flow on the west side of Wizard Island, with some deep blue to turquoise water in the shallows around the little islands and in the coves and bays in between them. In case you're wondering what Crater Lake looks like beneath all the water, click here for a great underwater view as seen from The Watchman. You'll see that there is another cinder cone in Crater Lake, one completely under water.
I didn't climb the trail to The Watchman Lookout Station; it looked a little inhospitable to me.

Some References:Bacon, 1983, Eruptive History of Mount Mazama and Crater Lake Caldera, Cascade Range, U.S.A.: Journal of Volcanology and Geothermal Research, v.18, p.57-115.

Bacon, C.R., 2008, Geologic Map of Mount Mazama and Crater Lake Caldera, Oregon, Including the Database for the Geologic Map of Mount Mazama and Crater Lake Caldera, Oregon by David W. Ramsey, Dillon R. Dutton, and Charles R. Bacon: U.S. Geol. Survey Map SIM-2832.

Cranson, K.R., 2001/2002, Cinder Cones in Crater Lake National Park: Nature Notes From Crater Lake v. 32-33.

Davis, J.O., 1977, Quaternary tephrochronology of the Lake Lahontan area, Nevada and California: Univ. Idaho PhD dissertation, 168 p [listed here].

Davis, J.O., 1978, Quaternary tephrochronology of the Lake Lahontan area, Nevada and California: Nevada Archeological Survey Research Paper 7, 137 p [pdf].

Davis, J.O., 1985, Correlation of late Quaternary tephra layers in a long Pluvial sequence near Summer Lake, Oregon: Quaternary Research, v. 23, p. 38–53.

Williams, Howel, 1942, The geology of Crater Lake National Park, Oregon: Carnegie Institution of Washington Publication 540, 162 p.