Looking For Detachment

Travel Day Three, Part #2: Annie Creek

2009-11-05T08:14:00.000-08:00

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. You can view a nicer version of this map of Crater Lake at Ponderosa, and it's also the first pit stop location after turning off from Highway 97.
I just love the trees you drive through on this part of the road!
The second unmarked pullout past Ponderosa, located here on Google Maps has good views across the canyon formed by Annie Creek, along with some more wonderful trees. Look for trails, possibly made by geologists on former field trips.
The walls on both sides of the canyon are steep. In some places you can just barely see over the edge; in other places you can clamber down the slippery upper slopes - don't slide too far, there are columnar cliffs below.
An upper layer of bedded, air-fall ash overlies an andesitic, scoria-rich ash flow deposit (called "andesite scoria" on signs in the area), which has weathered into crude columns. Cooling cracks in the andesite scoria do not appear to make it through the overlying deposits.

On to the next stop, the fourth unmarked pullout past Ponderosa (Google Maps location).

It's here that I slid down the upper ash layer, down to the andesite scoria below. The green masses above the dark rock I have my foot on consist of trees and plants across the canyon.
This is the same dark rock in the foreground, and now we can see the steep canyon wall on the other side of Annie Creek, with a dark talus slope below the columnar unit. I'm standing on the uppermost part of the andesite scoria.
Looking to the side from nearly the same vantage point, we can see some of the irregular shapes formed by erosion of the bedrock. This looks like a hoodoo to me.
The canyon at this same unnamed overlook is really pretty, and includes this waterfall where a small side stream flows over the andesite scoria.
More of the same canyon wall just to the left of the previous photo, with hanging gardens, trees growing on the side of the canyon, and layering in the columnar andesite scoria.
And here I've finally found some incipient pinnacle shapes. This is about as good as it gets below Annie Falls. The road to The Pinnacles overlook, with rock that looks like this, was closed.
Possibly the cooling cracks have extended from the columnar scoria a little ways into to the overlying ash deposit here, forming these miniature pinnacles.
This is Godfrey Glen, which can be seen from the Fossil Fumaroles overlook (Google Maps location). The upper ash is the tree-covered slope former above the dark unit of the andesitic scoria ash-flow deposit. Columns and pinnacles are especially prevalent near the top and middle (or bottom?) of this dark unit. The golden brownish rock below consists of a dacitic pumice flow deposit. All this rock was erupted during the climactic eruption of Mt. Mazama - 6,845±50 carbon-14 years B.P. or about 7,700 years ago (Bacon, 1983) - which then collapsed to form the caldera that is now filled by Crater Lake.
Weird, hoodoo shapes in andesite scoria in the foreground.
A couple pinnacles across the canyon. Annie Creek can be seen in the bottom of the photo.

Some References:

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

Decker, R., and Decker, B., 1995, Road Guide to Crater Lake National Park: Double Decker Press, 47 pp (?).

Williams, H., 1942, The Geology of Crater Lake National Park, Oregon With a reconnaissance of the Cascade Range southward to Mount Shasta: Carnegie Institution of Washington Publication 540, 162 pp.

Crater Lake & Mount Mazama, at the Cascades Volcano Observatory (CVO) website.

Mazama Ash, at the CVO website.

Summary of the Eruptive History of Mount Mazama, at the CVO website.

Road Song: Telegraph Road

2009-11-03T21:30:00.000-08:00

I've been a bit down in the dumps today, so I've been going through old and depressing songs, trying to find something to cheer me up. Maybe that seems a bit perverse, but watching sad movies works sometimes, so why not sad songs - and anyway, the end hints at a happy ending.

Dire Straits: Telegraph Road (lyrics)
Album: Love over Gold, 1982

NOTE: Videos of Telegraph Road are usually found in two parts, with the first part ususally ending at the end of the lyrics, before the long, final instrumental section. This pair of videos is split toward the end of the lyrical part. I don't really like that, but I thought the recording was better overall. Also, there is no official Dire Straits webpage, because they have been disbanded for several years.

As you can probably tell from the post title, this is one of those hundreds of road songs that I thought I had on a list somewhere. In fact, I thought I had recorded this song on one of a series of 90-minute tapes I made in the late 1980's (that was before one could record CD's). I now have a CD version of two of those tapes, recorded for me earlier this year by a geo-colleague who had the foresight to save copies. The CD also contains the contents of two road-song tapes made at about the same time by that geo-type. And it contains additional songs - including what was a non-road-song tape - and some movie clips pertinent to exploration, travel, or having otherwise cultish or historic value.

I'm pretty sure that I made three road song tapes, and the CD contains two of those. The first one was called "Life in the Fast Lane." The second was called "Tucson to Tucumcari." The third, I just don't know. "On the Road Again" - maybe?

Highlights of Travel Day Three #1

2009-10-31T12:57:00.000-07:00

I'm back to the intermittent series I started more than a week ago, which shows photos and geology from my travels to the GSA Annual Meeting - and back again, as soon as I get that far. Last you saw of this series, I had just arrived in Klamath Falls, Oregon, and was enjoying an IPA at a local pub. The morning of the third day dawned cloudy, with very nice lighting. I enjoyed the chill air, and walked around downtown KFalls while drinking coffee from a tiny styrofoam cup provided by the motel office. After several cupfuls, I finally got underway and headed north on Highway 97, which is now being called The Dalles-California Highway. I've always called Highway 97 in Oregon "The Bend Highway" - because it goes through Bend - and personally think that any highway running through Oregon should not be allowed to have the word "California" attached to it. I say this as a bred (barely) and born Oregonian.
Along the road, just barely north of town, you will come to a roadcut with some bright, white rocks (Google Maps location). I remember this roadcut from a very long time ago, when I was a young girl growing up in California (yes, the ignominy of it all). We traveled to Oregon at least yearly, often on this highway. A diatomite mine, now inactive, sits along the side of the highway just south of this roadcut - if I remember right. I didn't find an online reference to the old mine.
This is one of my favorite roadcuts. When I first drove the highway myself in 1975, I remembered the rocks from decades past. The white, diatomaceous lake sediments or mudstones of late Miocene to Pliocene age are overlain by a basalt flow (geologic map). You can see the upright columnar jointing in the flow.

Somewhere, in a box in some garage in Alaska, there might be a very old hand sample from this roadcut. Maybe.
Just around the corner to the north, Highway 97 goes into a straight stretch, pointing straight at several exposures of young-looking fault scarps belonging to the East Klamath Lake Fault Zone. The zone is seismically active. This article makes it look like there was a 1947 earthquake along or just north of the mapped zone, and this CVO page discusses the West and East Klamath Fault Zones in relation to Crater Lake and historic earthquakes. The fault can be seen in the large cinder/gravel mine to the right of the highway - which is accessible when it isn't active - and it can be seen in a very good and accessible exposure on the same hillside, just left of where the highway is pointing in the above photo.
To get to the best exposure I've seen, turn right on this paved road, then immediately turn left into the gravel ramp and old road seen in the center of the photo beyond the paved road. You can park somewhere along the old road, and then walk to the scarp.
This exposure of the fault scarp (Google Maps location) is accessible with some hiking up the steep slope. I didn't hike up this time, but have on previous occasions. I've also poked around the cinder/gravel mine, a few years back when it was closed. The fault places bedrock of basaltic cinders and possible flows against somewhat reddish older alluvium. It looked to me like younger, lighter brown talus was not offset by the fault. The fault surface is smooth, grooved, and slickensided, and compares favorably to the Genoa fault scarp south of Carson City for a great fault exposure.

I have some old non-digital photos of this Klamath Basin fault surface, and will surely scan them someday.
Fault surfaces are visible along the highway for several miles, mostly in areas where rocks are kept behind barriers and metal screens. The road is narrow, often with curves, and it cuts into a steep, talus-ridden hillside. Traffic is often incessant. There are a few small pullouts on the southbound side of the road - these are hard to stop in because they are so short. They also precipitously overhang the railroad, which is below the highway closer to the lake. I've stopped at one or two of these pullouts; they don't really provide very good access to the roadcuts.
At this pullout on the east side of Highway 97, you can look across Upper Klamath Lake and see several volcanoes. It was a bit cloudy, so I got decent photos of only two, Mount Harriman, above, and Pelican Butte, below. Mount Harriman is one of four (or more?) shield volcanoes inside the Mountain Lakes Wilderness. Pelican Butte is a shield volcano just northeast of Mount McLoughlin.

Just up the road apiece, I saw these signs, and made a sudden, unplanned side trip... to Crater Lake.

A Reference:
Priest, G. R., Hladky, F. R., and Murray, R. B., 2008, Geologic Map of the Klamath Falls area, Klamath County, Oregon: State of Oregon Dept. of Geol. and Mineral Resources, Map GMS-118.

Hanging Around

2009-10-28T15:50:00.000-07:00

...at the GSA meeting. And what better place to do it than with a bunch of other geobloggers and geotweeters in a friendly pub? I didn't take many photos during our meetup-tweetup, but got this one of Callan Bentley - who said, at the time, that it was a "great" photo. Callan has a photo of 18 of the 19 bloggers right here. He and several others have written more extensively about the pub, the beer, and the bloggers. (Well, no one wrote much about the beer - I thought it was just great, but don't remember anything specific.) If I missed any writeups, go ahead and let me know!
Like I said, I really didn't take many photos in the pub, instead, I took some pics while a few of us were taking the train back across the river to the convention center area. Above: Jessica Ball of Magma Cum Laude and Ron Schott of Ron Schott's Geology Home Companion Blog.
More: Brian Romans of Clastic Detritus, Jim Lehane of Dino Jim's Musings, and Callan Bentley of NOVA Geoblog.
Here's Callan with Kyle House of Geologic Frothings and Fresh Geologic Froth, with Kim Hannula and All My Faults Are Stress Related looking on.
Anne Jefferson of Highly Allochthonous has been hanging on all this time, and is now conversing with Kim.

It was a great night, I enjoyed meeting so many geobloggers, and look forward to doing this again sometime! A full list of the blogger and tweeter attendees can be found at NOVA Geoblog.

Getting Back from GSA

2009-10-27T12:43:00.000-07:00

I got back from the Portland GSA meeting yesterday, arriving beneath partly cloudy skies with scattered wave clouds like the ones above. I'm not sure I feel like I'm back, however - I have a huge number of things to do, including possibly driving back across the state again because of miscellaneous appointments. As far as blogging goes, in the next several days I'll be getting around to a few more travel and meeting highlights - from both before and after the meeting - but these updates may come along gradually as I try to settle in to some kind of post-travel schedule, while also working on laundry and other mundane things. I also want to review contacts I made at the meeting, update my resume more completely, and plan a bit for the next meeting - Northwest Mining in Reno in December.

GSA Report #2

2009-10-21T10:05:00.000-07:00

It's Wednesday morning and raining steadily, unlike this shot from Monday morning. GSA Annual meeting events at the Oregon Convention Center are winding down somewhat: many geologists leave Tuesday night or Wednesday morning, though talks and posters continue through the day, and post-meeting field trips and short courses are still to come.
The exhibit hall, combined with the poster hall and graduate school recruiting booths, is huge - none of the pictures I've taken really show the size - I'd need to stitch together a full-circle panorama, but maybe you can get an idea from this picture showing a portion of half of the exhibits. Photos aren't allowed in the poster area behind me.
Geologists, guests, and exhibitors walk down the "Geoscience Highway" - this is the center area of the exhibit hall, with the photo looking from one end to the other. About half the exhibits are on each side of this central dividing area. This year, the GSA has internet cafes of ready-to-use computers scattered through the meeting halls, including one inside the exhibits. Wifi is available everywhere that I've tried connecting, for those who've brought their own computers or smartphones.
One of the reasons I've always liked coming to annual and sectional GSA meetings is to cruise the rock and mineral booths. This year, there are many; they offer rocks, minerals, fossils, jewelry, and other items made from polished rock and stone.

And now for a summary of where I've been and what I've done. Yesterday, I spent a good portion of the morning and afternoon in the SEG sessions on Magmas and Volatiles: Linking Granites, Volcanoes, Geothermal Systems, and Mineral Deposits I & II (158 and 204). These sessions covered a wide range of topics from porphyry copper deposits to Carlin-type gold deposits, from zircons to fluid inclusions, and from subduction to low-angle normal faulting.

In the afternoon, I also bounced around the convention center, going to talks by various individuals including one by my first employer and mentor, a talk by geoblogger Brian Romans (200-8), and a talk by geoblogger Kim Hannula (200-12).

For the evening, I was invited to the QG&G awards meeting by Bud Burke, an old friend of mine from ties that go back as far as early grad school. I saw several old friends there, reconnected with people I hadn't expected to see, and actually managed to conduct some business relating to a Pleistocene lake in central Nevada. A paper about the lake will finally be published; I'll be a co-author when it comes out, probably because I provided the initial information about the area and was there when the first work was done, and because I tried to get the ball rolling on the article way back in the early 1990's. I'll say more about that when the paper is published.

Today I plan to be in the SEG sessions most of the day: morning and afternoon.

Be the way, summary posts about the GSA meetings by various geobloggers can be found at this GSA page: From the Blogosphere. I don't think the list is complete.

GSA Meeting Report 1

2009-10-19T11:00:00.000-07:00

I arrived in Portland Friday night, which was a bit early, so I spent most of Saturday getting ready for the meeting: picking up my badge and free drink tokes for Sunday through Wednesday receptions, setting up my approximate meeting schedule, meeting and socializing with Kim Hannula and others near one of the Starbucks, and going to the GSA Awards reception, which had free wine, beer, and food after a series of great and moving awards.

Sunday was a day of many talks. The annual GSA meeting is a large meeting if you measure by the number of scientific talks given. On Sunday morning, 24 sessions of about 14 talks each were running simultaneously in 24 separate meeting rooms. That many sessions run simultaneously every morning and every afternoon (about 48 sessions per day not counting posters which change daily) for 4 days in a row. This gives me ample opportunity to want to be in more than two places at once, besides trying to squeeze in going to poster sessions and the exhibit hall. Sunday morning, I spent some time at the SEG talks on porphyry copper deposits and gold and copper transport in crustal fluids (1), and finding those somewhat dry, I bounced over to the detachment session (12), which was on the opposite side of the large Oregon Convention Center. There I learned about such things as 'mini-detachments' and graded sandy layers in fault zones. Then I bounced back to find out how soil samples reflect the West and East Pebble deposit at depth (well and hardly at all, respectively).

That was Sunday morning. For the afternoon, I decided to attend only one session, so stayed in the Google Earth to Geoblogs session (53), where several fellow geobloggers - and others - gave excellent and inspiring talks and demonstrations. I met several bloggers I hadn't met before, including Ron Schott, Jim Repka, Callan Bentley, and Lee Allison. I expect to meet several more, along with #geotweeters, tonight at a planned get-together.

Today, the morning seems slow to me as far as talks go. Yes, there are 24 sessions going on right now, and some very interesting talks scattered here and there through the convention center. I'm attending the exhibit hall and blogging, rather than going to morning talks. This afternoon, I get to choose between Volcanism, Impact, and Mass Extinctions (133), Geology in the National Parks (136), LIPs (138), and Virtual Globes to Geoblogs (144). I haven't yet decided!

The best part of meetings, though, is meeting people, which for me often involves seeing people I haven't seen in 10 to 20 years. If you stay in the talks all day long, you don't see anyone - wandering around the exhibits and posters and going to the evening socializing events is something I highly recommend.

I thought I'd show you a couple photos - of the convention center and exhibit hall - but I left my camera downloading cord over in the hotel.

I'll try to have another meeting update, but don't promise anything.

Highlights of the Day: Travel Day Two

2009-10-17T14:50:00.000-07:00

I'm already at the national GSA Meeting in Portland, but I took my time getting here, four days to be precise. Here are a few highlights from travel day two.
The lighting was great between Susanville and Klamath Falls. Here, I'm dropping into a Basin and Range valley, the valley that's home to Eagle Lake (TerraServer link). Eagle Lake, which is reported to be a closed basin with no hydrologic outlet, is shown as being either in or out of the Great Basin, depending on whose map you use. Eagle Lake was not connected to Pleistocene Lake Lahontan.
Eagle Lake (Google Maps link), looking almost west, from Highway 139.
This is a basalt dike on the east side of Highway 139, just south of Lassen County Milepost 52 (Google Maps location), and just before you get to the Willow Creek Campground if you're driving north.
The columnar jointing in the dike is nearly horizontal, making the rock look like a bunch of stacked logs.
Looking end-on at the pile of stacked logs, the cross-section through the stacked columns shows the typical though irregular polygonal shapes common to basalt columns. Kim posted about another dike with horizontal columnar joints earlier this year, and Andrew's article on basalt columns has a great photo of a piece of basalt with an almost perfect hexagonal shape. It seems like I've seen another post more recently on columnar jointing, but I'm not finding it right now.
Closer to my KFalls destination, it started raining, but without the intensity of the previous day.
And then there was the IPA awaiting me at The Creamery Brew Pub & Grill . . .

Mid-Monthly Art: Mojave Hilton

2009-10-15T08:27:00.000-07:00

This brightly painted version of The Mojave Hilton is based on an old, now faded photograph of the miner's shack or hunting cabin known as the Mojave Hilton, which is located in the Vontrigger Hills of California. I'm not going to give the precise location, because the shack has seen some ill use in the past few years or decades. The area is inside the East Mojave National Preserve (1994), formerly known as the East Mojave Scenic Area (1980).
This photo, now part of a cut-to-pieces collage, was taken in 1985 by the second geologist in the picture - that's right, the one that isn't me! I don't know how my 1981 field partner and I missed this cabin - we probably drove right by while focusing on volcanic rocks of the nearby Castle Mountains and the even closer Hackberry Mountain.

Back in '85, a sign over the door said "something Hilton," although all I can read now is the "Hilton" part, even on the original print.

The Mojave Hilton was used by hunters when we visited in 1985. The front steps were almost new. Although I never met anyone while stopping by, a sign-in book and wall sign-in lists made it clear that the place was used on a fairly regular basis.
This is the way the Mojave Hilton looked in early May, 2009: a little bit worse for wear, but still hanging in there.
These newer photos show that the sign over the door is gone.
Instead, the door has a hantavirus warning, which was plastered on by DOI.
"DO NOT SWEEP OR VACUUM." Thanks. I wasn't planning on it!
I did go in, though - it's an irresistable pastime of exploration geologists: examine every shack or cabin you find in the field, providing that the interior is sound. The note above was written in June, 1983. It names the cabin as "THE MOJAVE HILTON" and mentions the new front steps and other improvements.
Typical sign-ins on the wall. I don't remember for sure if there was a sign-in book or not. For sure there was one in either this cabin OR another semi-nearby, well-kept cabin, but I'm not sure which one had the book.
The stove that was new in 1983.
The kitchen area.
The bedroom area. Here's where you can see the disorder that the cabin has come to. To clean up, you'd need serious dust protection. The business cards overhead are another way of signing in. (I didn't leave one!)
The Mojave Hilton from the rear, showing the classic western way of holding the roof on by adding rocks - protection against windstorms.
The Mojave Hilton, as seen from the old mine shaft that the cabin was originally built to service, with the volcanic rocks of Hackberry Mountain in the background.
This is the main shaft (or decline) where someone went after whatever they thought was minable on this property. The mine dump shows signs of quartz and minor sulfides. The dump is small, though - either the mine didn't go deep, or some rock was hauled to an unknown mill.
A closer look, which I took by holding my camera at the proper angle and rotating the screen, not by actually getting closer. The timbers look a little rotten in places. The country rock, gneiss or granite, is shot with narrow stockworky veins of unknown type.
And looking farther down the decline - hey, I'm not going in there, you shouldn't either! Especially don't trust that rickety-looking ladder.
It would be a nice place to live, don't you think?

Copyright © 2009 Looking for Detachment.
Original watercolor Copyright © 2002.
All Rights Reserved.

Through the Rain

2009-10-14T09:30:00.000-07:00

Yesterday, my travels toward the GSA meeting in Portland, Oregon, took me across Nevada into the face of the oncoming storm.
Lenticular cloud in eastern Nevada.

Dust storm, with overhead mass of lenticulars, while approaching Eureka.
Serious rain started as I crossed Big Smoky Valley and drove toward the Toiyabe Range. I couldn't hardly see the mountains until I got into them, and Big Smoky Valley to the south was a near whiteout (gray-out?) from the rain and low clouds.
Looking south toward the west side of the Toiyabe Range from the center of Reese River Valley: clouds roil over the back side of the mountain near Big Creek.

A relatively dry spell ensued, until somewhere east of Fallon.
Good news! The windmill is back up and running at West Gate. A lot of happy cows were lying down in the nearby field. Happy cows are ones that are lying down, rather than having to stand up and spend their entire time eating. Cows aren't usually that "happy" in the desert and steppe rangelands of Nevada and southern California (the Mojave Desert).

Driving from Fallon onward included barely being able to see with windshield wipers going full blast from the intensity of the rain and from semis splashing water all over while passing me in the canyon of the Truckee River east of Reno. There was enough standing water on the roads to cause unexpected hydroplaning in places - and the winds were blasting sideways across the water-sheeted concrete highway between Fallon and Fernley, strong enough locally to push my truck sideways.

Oh, and how much gas did I have? Usually that isn't a problem for me, but I didn't want to stop and risk getting completely drenched, didn't want to stop and risk driving over the mountain pass in the coming darkness. My odometer seemed to be telling me I had been getting 20 mpg or more for the last 400 to 500+ miles. Since I couldn't believe that, I chose to think I had not reset the odometer, and must not have traveled as far as it said, thus giving me enough gas to get to my destination without refilling. About 40 miles from the next gas station, I did the math and realized that with less than a quarter of a 30 gallon tank, I had really gone 560+ miles, another 40 would make that 600 miles, a precise 20 mpg. I usually fill up at 500 miles, and although I probably had enough gas to make it 40 miles - probably, maybe - I turned around and drove back less than a quarter mile to the last gas station, getting a little damp for the trouble. I'm packed for wet and cold weather, but was only dressed for cold.
Finally, after driving through the most consistently intense rainstorm I've seen in Nevada for a long time - over a broad area from east of Fallon to beyond Reno - I spotted this bit of clearing on Highway 395 south of the Honey Lake rest stop.

Pennsylvania Canyon: Getting There

2009-10-13T09:33:00.000-07:00

I’ve already written a little about trying to get into Pennsylvania Canyon – the site of a long-ago truck mishap – on the first day of my most recent Caliente expedition. I had first tried getting in from Elgin, but only half-heartedly - because I’d never been on that part of the road, because the road looked lousy, and because the sign said “Road Damaged Ahead.” Later that first day, after a few other escapades, I drove part way up the road to the Ella Mountain Lookout, which is the other way in to Pennsylvania Canyon.
On that first day, I made it past Tepee Rocks, to this sign: Ella Mountain Lookout, 10.
And then I went beyond that to this burned area, where I realized the rest of the way would be too long for a late afternoon drive. Ella Mountain Lookout can be seen as a couple tiny-looking towers on the left edge of the photo, on the distant hill between the two charred branches.

The second day, I dedicated myself to getting into Pennsylvania Canyon by way of the Ella Mountain Lookout road. I made it to the Ella Mountain Lookout 10 sign at 9:30, to the burn at 9:40. The roads were long, and the way in was briefly obscured by faulty memory and a lack of good topo maps. About 6 miles in from the sign that said 10 miles, I came to a T in the road - a T I wasn't expecting, a T with no sign. I turned the right way, at first - to the west - but not believing the lookout road could deteriorate so rapidly, I turned around, went back to the T, and drove east.
After going way too many miles the wrong way, going lower and lower in elevation and farther and farther away, I found a place to turn around - lo and behold, one where I could still see the lookout in the distance to the west, one where bands of sage sparrows were chip, chipping and flying from bush to bush.

I turned around at 10:10 am. I went back to the T junction, and kept going west, what had I been thinking!? At that point, the long road got steep and rocky.
I passed the Ella Mountain 3 sign at 10:30 (why hadn't there been a sign at the T, they were everywhere else!), and made it to this rocky turn with a view at 10:40. It was here that I discovered that the rock I’d been bumping my way slowly across was a poorly welded, well-indurated tuff, seen above in the right foreground. I was also reminded of two unexpected trees. See the one on the right, growing on the tuff? That's an oak. What about those tall trees behind it and across the road - aren't they a little tall for piñons?
Yes, it's an oak. The acorns somehow brought back memories of my initial, long-ago surprise at seeing oak trees in Nevada. The tall trees I still didn't recognize.
I’ve now come to a main fork in the road. Ella Mountain is 1 mile to the right, and Elgin - “Road Damaged Ahead" - is 10 miles to the left. The left road is the road into Pennsylvania Canyon. I arrived here at 10:50, and then got underway by 11:15 after taking pictures from the lookout.

Do I seem a little overly time conscious? Well, I was. I hadn't filled the gas tank in Caliente that morning, so I was watching mileage and time carefully so I wouldn't get too far down any one road.

To be continued…

Earth Science Week 2009

2009-10-12T08:54:00.000-07:00

Earth Science Week started yesterday, and I noticed that not a single thing is listed under "What's Going On" for the entire state of Nevada. (I also noticed in general that much of the Earth Science Week website is still focused on 2008, with many links either broken or linking to events and sites from last year.)

Actually, I've been a little bamboozled by Earth Science Week this year. It almost always overlaps with the Annual GSA meeting, which is of no concern to me in years when I don't go. This year, however, I am going, so I inconveniently didn't plan anything for Earth Science Week.

I belatedly noticed that the Nevada Bureau of Mines and Geology (NBMG) scheduled their Earth Science Week field trips for this last weekend, meaning that the field trips ran on Saturday and Sunday, October 10th and 11th. And I missed out! I have gone on these field trips on more than one occasion, and have found them enjoyable. They are open to the public, and kids, families, and school teachers are especially welcome. Local geologists from the Geological Society of Nevada (GSN), accompany the trip as informal field trip guides to help answer questions (and to learn more about new areas they might not have visited).

This year's field trip was called "Digging Deeper into the Comstock." An online road log is available, so you can take the trip on your own sometime (or at least part of it), whenever it is convenient.

Next year, I'm going to have to mark my calendar much earlier in the year. I had assumed that the field trips would run while I was away at GSA, so by the time the announcement came out, I had already made other plans. And, anyway, the last month turned out to be a little hectic in some ways.

Because I'm not doing anything for Earth Science Week myself this year, I'd like to point you to a few sites of interest:

Kim at All My Faults are Stress Related has a few ideas, including:
Donating to the Geobloggers DonorsChoose challenge, which is highlighted and described by Anne at Highly Allochthonous, and
Michael at Through the Sandglass describes the Earth Science Literacy Initiative's (ESLI) nine Big Ideas in terms of, you guessed it, sand!

I hope you find something of interest!

UPDATE: This post has been submitted to Accretionary Wedge #21 on Earth Science Outreach.

Recent Hike: Less Snow

2009-10-11T16:27:00.000-07:00

Having just gotten back from a relatively short afternoon hike, I thought I'd post a few pictures, just to let you know that we have gone back to fairly usual fall weather. Cooler temperatures are still the norm, but we've had several days of sunny skies, warm afternoons, and off-and-on winds.
Clouds moved in with the winds late this afternoon, making things seem just slightly chillier, but not much. As you can see, most of the snow is off all but the highest, north-facing peaks. Compare this photo to one taken last week.
Compare this photo, with all leaves on the high-mountain aspens gone, to this one taken about two weeks ago. It's definitely fall.

I'll be traveling part of this week - on my way to the Annual GSA Meeting in Portland - then will be at the meeting, then traveling back. I have a couple posts already scheduled, but otherwise am not sure how posting will go. I'll try to get in a couple posts from the meeting - but having never posted from a meeting before, I'm not sure how that will go. We'll see.

Tweets for the Week #2

2009-10-11T13:02:00.000-07:00

Continuing with the blogging of interesting links I tweeted on Twitter this week - as per last week, with oldest at the top, youngest at the bottom (ineverse geological order):

New blogpost "Geology and wine Sunday" (via @mihaela4021)

Protect yourself & Oregon schoolkids from zombie attacks - with rock hammers! (via @stressrelated)

Where's your laptop come from? Everywhere, basically. (via @stressrelated, @justarikia, & @wired)

That being said, the leading copper producing country is not China. Top 5 in order: Chile, U.S., Peru, China, Australia.

"There shouldn't be any impacts." ha! Discovery of new cave critters may jeopardize Vegas water grab. (via @highcountrynews)

USGS has an opening for an Economic Geologist (Research) in their Anchorage, Alaska office.

Geologist postition with CEMEX in Sacramento for recent graduate. Search: California; click: Geologist.

Two tenure track geology positions available at UNR (NBMG) in Econ Geol, Structural Geol, Tectonics, Geol Hazards, et al.

Two Deadly Quakes: Is Earth Unusually Active? [No.] (via @BoreholeGroup)

Have you donated to the Geobloggers' DonorsChoose challenge? Help kids learn really cool science. (via @Allochthonous)

How to clean up a broken fluorescent light bulb or other mercury spill. (via @mcmoots h/t @EPAregion9)

The Impact of Nature Experience on Willingness to Support Conservation. (via @BoraZ)

Gold prices hit a record high today [6 Oct 09] at $1,039.70 an ounce. (via @rgj)

Vanuatu earthquake/tsunami summary plus links and background. (via @aboutgeology)

Even the Camels Are Dying. RT @dotearth

Three magnitude 7's in one day - at Shaking Earth.

Forecast now for only moderate El Nino, temps plateaued. (via @jfleck)

Article about age of Earth's magnetic field indicates that it may be older than earlier estimates. (via @BoreholeGroup)

Find a Native Plant Society in your area of the country. (via @mactavish, @CNPS_org, and @PineLilyFNPS)

Did you know that GSA is on Facebook? (via @geosociety)

Some photos from the field, OR and WA - at Pools and Riffles.

Geoblogger's pow-wow in Portland - at NOVA Geoblog.

Geotagged photo album of Walker River / Lake map area. Open it in GE for fun. (via @drjerque)

And a few links not strictly geoscience or science related:
Dilbert and Wally recommend Twitter to the boss. (via @mike_elgan)

Blogs can be regulated by the Feds, but not protected from Feds by Shield Laws. (via @BoraZ & @jayrosen_nyu)

I think I'll keep calling it The Test Site. The Nevada Test Site is getting a name change. (via @jfleck & @plutoniumpage)

Ray Bradbury, painter. (via @pussreboots @LATimesbooks)

Nobel Peace Prize's Notable Omissions. (via @nprnews)

Including Ensign and McCain. 30 GOP Senators Vote to Defend Gang Rape. (via @GrrlScientist)

Two Years Ago Today: Two Drill Rigs

2009-10-09T09:04:00.001-07:00

Two years ago today, I went out early in the morning to visit two drill rigs. This is the first drill rig. They are fairly deep in the hole, but we'd like to go deeper.
The shadows were long, and although there was frost here and there, the ground wasn't frozen. Neither drill rig was inside an active mine; they were conducting brownfields exploration around the edges of an old pit.
When I arrived at the second drill rig, the sun was still low on the horizon with the frost unmelted in the shadows.
The rig had twisted off in bad ground - very bad ground - at less than 200 feet, leaving a lot of pipe in the hole. The driller, who had been on shift with his crew since midnight, was not happy.
The front end is jacked up to level the rig on this slightly non-level drill pad. On this particular pad, the only blading required was minor smoothing.
While I was there, the driller shut the rig down prior to trying to get the twisted-off steel out of the ground. If you know how many pieces of pipe were on the truck to begin with, you can figure out how many feet of drill steel is - in this case - lost in the hole.
This is some of the miscellaneous equipment and paraphernalia near the sampling side of the drill rig.

I stayed on site for most of the morning. It turned out that both rigs were going to need to move to start new holes, with neither having reached the target depth, and I had to show them the new sites and make sure the drillers were okay with the sites. At least one of the sites needed a bit more cat work prior to the move.

Meadow Valley Wash: Up the Canyon to Caliente

2009-10-08T08:59:00.000-07:00

It’s now about mid-afternoon on the first day of my most recent Caliente field excursion, and after a quick lunch under a cottonwood tree on the side of the road, I decide that it’s time to continue my journey north on Highway 317 in Meadow Valley Wash. I’ve left Cottonwood Canyon, Elgin, and “the Narrows” behind. I have one more planned stop - despite the smoke and afternoon heat - before I head to the motel in Caliente: I want to find the road into our old mapping project near Boyd, so I can drive in and take a look around. In the meantime, one of the many trains that passes through the canyon has caught up with me.
The train keeps pace with me as I approach our 1978 camp area, which is just to the right of the highway in this photo. The train pulls through the bridge near camp and approaches the Boyd siding. Hard to say which vehicle is going faster, the locomotive or my truck – railway speed limits from Elgin to Caliente are mostly in the 30 to 40 mph range, and the highway speed limit is 35 mph or less, often marked 20, 25, or 30 mph because of curves and washouts.

What am I looking for exactly? Well, having not examined the old topo maps in detail, I’m looking for a place from memory, a place where we crossed over or under the train tracks. I think that place is just north of the Boyd siding, near the steep reddish cliffs we mapped, but I can’t really remember whether we drove over or under the tracks.
Whoosh! Past the north end of the Boyd siding I go, and past one possible way under the tracks. I continue driving north with the train, rather than stopping. By now, it seems like I'm racing the train - but I'd better not do that, because of all the washouts and places where the pavement was undercut by the 2005 flood.
I finally come to this little cement underpass, and although I'm north of the unnamed canyon central to the old project area, I decide to check it out - because it's there.
With the train still moving north, I walk under the cement underpass to the east side. No, this is not the place – not the place we crossed the tracks to get to the mapping project back in 1978. Although scrape marks about truck high on the wall suggest that people have driven through, the road heads off to the north, away from the area I’m trying to reach.
While driving north to the cement underpass, I’ve looked along this entire length of track for any approaches that might be possible places to cross over the tracks, and I really haven’t seen any. I take one last chance that there might be a place to drive over the tracks at this north Boyd marker - but as you can see, there isn't. Part of our former project area can be seen in the background: all those reddish, rhyolitic rocks, capped by what may be the Ox Valley Tuff.

At this point, I drive south, back towards the only other underpass I've seen, the only place that might provide access into the old project area.
Yes! This is the place! It even looks familiar! This underpass is here, just a little south of the northern Boyd marker (previous photo) and just a little north of the north end of the Boyd siding. This is the place we used to drive under the tracks to get to our map area. As you can see, it's chock full of green, rooted tumbleweeds (Russian thistle).
The road went under the bridge, and then straight into those bushes on the far side before turning to the left to head up the unnamed dry wash north of the reddish cliffs.
You can vaguely see where the old road would have gone into the bushes, although I really couldn’t follow it from there. The underpass is much higher and wider than the puny cement thing I walked under earlier. It doesn't, however, show any signs of recent use as a roadway!
As I walked around on the east side of the bridge, I found this railroad-parallel, two-track road - also inaccessible. I was disappointed not to be able to spend the rest of the afternoon driving up the old canyon road - possibly with vehicular agression I could have gotten part way in before getting stuck - and with the thick smoke hanging over the canyon and the afternoon heat increasing, I decided against climbing the steep talus slopes of the old project area.
So, I walked back to my truck...
...and drove north, bypassing the entrance to Kershaw-Ryan State Park on my way to Caliente.

But was I done for the day? No. I had it mind that I still had time to drive to the Ella Mountain Lookout, and from there into Pennsylvania Canyon from the east side, since I hadn't made it in from the west side at Elgin. That way, I would only have to stay in Caliente one more night. (Yay!) So I drove through Caliente and turned right onto the Clover Creek Road, took the dirt road past Tepee Rocks, and made it one hour into what turned out to be a four-hour-long, one-way journey to the lookout and into the canyon, before I realized that more than an afternoon's worth of driving was ahead of me if I continued on. I turned around.
Back in Caliente, I found a bar - but not the old Northern Lights that I remember from 1978. It closed about three or four years ago, according to some oldtimers patronizing the Shamrock Pub, which is next door to what used to be the now-defunct bar.
As I sat there, Classic Vinyl played "Do It Again" by Steely Dan. It seemed like my entire trip was an attempt to recreate the past or to somehow do it all over again.

You go back Jack do it again
Wheel turnin' 'round and 'round
You go back Jack do it again

15 Book Meme

2009-10-07T09:00:00.000-07:00

This book meme has been lying around in my draft folder for quite sometime, and I was just reminded of it today when reading the Bragging Rights Archive II at VWXYNot. While reading that archive I remembered that I had been tagged for this meme by virtue of having fallen out of a sailboat - at least once. The possible first time was in my childhood, and it may have been someone else who fell out, thereby leaving me with a permanent scar after imagining how terrible falling out would be. The for-sure second time was in Washoe Lake, Nevada, after the boom swung across the boat, causing me to fall out and the boat to tip over all at the same time. Falling out of boats of any kind is one of my least favorite things in the world; it can involve being in water over your head rather suddenly. In this particular instance, the sailboat was not rightable - after we both made it back to the boat to give it a try - because it turned out that the mast had no cover on top, so had completely filled with water. We had to drag it close to shore, it upside down - and several people got involved in the righting. Not me. Being there - hanging on to an upside down boat while my boating partner drifted away, then getting resucued by another sailboat, and then making the righting attempt while thoroughly waterlogged - had been enough for me.

Oh, back to the book meme. The official rules of the meme are "list fifteen books that had the most profound impact on you - ones you can think of in fifteen minutes or less." And here's where things slow down: 15 books? Which ones? Most profound effect, or just the ones I remember right off the bat? Or some combination of the two, perhaps?

Dune
Foundation Trilogy (is that 3?)
Hobbit and Lord of the Rings Trilogy (is that 4?)
Time Enough for Love - much more so than Stranger in a Strange Land.
Nightfall
Flowers for Algernon
Childhood's End - the only Arthur C. Clarke book I ever liked.
Catch-22
Cat's Cradle
The Martian Chronicles
Fahrenheit 451
The Mote in God's Eye
1984
East of Eden - or The Grapes of Wrath.
The Secret Garden

I'd like to list something heavy, like De Re Metallica, but really, I don't think that's what caused me to become an Economic Geologist, although it is a very good book on mining and prospecting, published in 1556.

I would also like to state, for the record, that at a certain time in my life I was considerably impressed with Ayn Rand. At the time, it was fairly common for people in college to read her books, almost like some kind of cult thing - I swear these were the same people also listening to the Grateful Dead, but I could be wrong. Three of her books have left some lasting impression on me, not entirely positive, especially after seeing part of one movie rendition, and after realizing retrospectively how the women in her books were characterized in a partly sexist, though strong, fashion. At this point, the only book I think worth reading if you haven't yet read any of her writing is We the Living.

I'm not sure if 1984 belongs on the list, but I put it there because I thought of it relatively quickly, and because the effect was strong. Fortunately, the strongest effects (rats) have faded with time. Perhaps one of the Russian novels should be listed instead, maybe One Day in the Life of Ivan Denisovitch or Master and Man.

As for tagging, this is a fairly old meme, so if you'd like to play, consider yourself tagged - also, any and all readers who had vegetable gardens this summer can consider themselves tagged.

First Snow, 2009

2009-10-05T11:52:00.000-07:00

We had our first snow yesterday and last night. This is what our garden looked like at about 1:00 pm yesterday.
This is what it looked like at about 2:00 pm. Snow kept falling off and on through the day and night, with maybe an inch more of accumulation.
Clouds early this morning were mostly wave clouds (lenticulars) stacked over the mountains - Duck Creek Range shown above - with smaller lenticulars scattered over the valley.
The view from our hiking hill, looking south of town toward the southern Egan Range, showed raggedy lenticulars, and a fairly light snowfall, except on the higher peaks.

Cheatgrass in the snow.

A nicely hexagonal ice crystal.

More ice crystals.

It's now clouded over nearly completely, although skies are supposed to clear. Hopefully the snow will mostly melt over the next week or so.

This first snow of 2009 has beat the first snow of 2008 by 6 days and the first snow of 2007 by 1 day.

Tweets for the Week

2009-10-04T11:27:00.000-07:00

It's becoming popular to blog links tweeted on Twitter; here are mine for the past week. This practise was started by Chris at Highly Allochthonous a few weeks ago, and recently taken up by Ole at Olelog. I'm typically a bit eclectic on Twitter - links will include geoblogs, other geological and geographical articles, and articles on other subjects. I have, of course, left out any links I tweeted to my own blog, so as not to be too redundant and overweening. I'm not sure if I'll commit to doing this weekly, though it's fairly easy using Twitter Search, as Chris pointed out in his most recent twitter-link post. I've listed these in chronological order, with the least recent first and the most recent last.

Crater Lake (Oregon) Web Cam (via @geographile & @Aife_Earthstone)

Just Posted: Joshua Tree Calendar for 2010 (via @canislatrans)

Yikes! Will have to tell MOH. Snowshoers are *7* times more likely to underestimate Avalanche Danger! (via @Sierratp)

Google map of requests to remove books from public libraries. (via @dvergano & @seanmcarroll)

A very good article on aging from Men's Journal. Kind of funny; kind of not. (via @LRockwellatty)

The most populated & tectonically active state subordinates oversight of geophysical risks to non-geos. (via @Geolitics)

Science "Journalism" by Press Release - at Outside the Interzone, on Italy's "supervolcano." (h/t Callan Bentley)

Samoan EQ: Now an 8.0 event, normal mechanism, depth a mere 10 km. (via @aboutgeology)

Powerful quake hits off Samoa islands, generates tsunami. None expected in Alaska or West Coast. (via @adndotcom)

Toyota will recall 3.8 million vehicles, its largest U.S. recall. (via @rgj) <---haven't noticed any problem w/ our Prius.

Interesting aftershock distribution... (via @miguelveraleon)

Is banning a font, like banning a book? What's the ugliest font? (via @peccavi & @sharebrain)

Lauren, on Polanski, at Feministe. Must-read. (via @canislatrans)

Back in the Mountains - rock glaciers by @geologyhappens

Nice job on the interview! @Allochthonous : BBC programme on natural disasters is available on Iplayer for the next week

A few pics from Salton Sea trip. (vai @FlorianBoyd)

Hey GeoBloggers! ... Take this survey (via @clasticdetritus)

Happy Water New Year! (via @WaterWired)

Wired.com on Asperger's Syndrome (via @Colo_kea)

Time to turn my computer on. The latest podClast is up! The Geobloggers in the Pub: SF (via @Yorrike)

And the earthquakes near Olancha, south of Lone Pine, continue.

The Keeler Earthquake Swarm - at Geotripper.

Friday Field Photos: Tepee Rocks

2009-10-02T10:39:00.000-07:00

More than a month ago, on my Caliente trips, while driving up the washboarded dirt road toward the Ella Mountain Lookout, I came around a corner and spied these unusual rock formations in tuff, formations I had forgotten all about since last seeing them in 1978.
These are the Tepee Rocks, located about 6 miles east-southeast of Caliente. They are a type of rock formation called tent rocks, teepee rocks, or hoodoos, and they have formed here in the tuff of Tepee Rocks (sometimes spelled "tuff of Teepee Rocks"). The tuff of Tepee Rocks is "crystal-poor, poorly welded, low-silica rhyolite ash-flow tuff" with an Ar-Ar age of 17.8 Ma (Rowley et al, 1995). It's about 100 m thick in the Tepee Rocks area.

To get to the Tepee Rocks, you drive east out of Caliente on a mostly dirt and sand road that follows the railroad along Clover Creek (Clover Creek Road). You may not need 4WD, but be prepared for soft sandy areas that appear suddenly and wide creek crossing. Before the Eccles siding, you turn south on the dirt road that goes to Ella Mountain and Fife Flat, among other places.
It can be a bit difficult to get the timing right for best sun-angle on these hoodoos; I made two stabs at it. Morning and afternoon, not too early and not too late, are best.
In this close-up, you can see some holes weathering out in the tuff, forming a small version of what is known as cavernous weathering. Hoodoo formation in general is explained here.
At the Tepee Rocks, the teepees or hoodoos are forming in massive, cavernous-weathering, very light gray to whitish tan tuff below layered, tan to light orange tuff, which may be part of the tuff of Tepee Rocks or may belong to an overlying formation. The layered tuff can be seen in the previous two photos.
A slope just south of the Tepee Rocks shows the massive tuff capped by the upper layered tuff and by overlying talus. Little hoodoos are starting to form as the whitish tan to light gray tuff weathers out from beneath the talus and capping tuff layer.
A few small teepees stick out on the lower part of this slope across the road from the Teepee Rocks. The cliffy formation capping this butte is probably not part of the tuff of Tepee Rocks, based on the description given by Rowley et al (1995).

Some References:
Page, W.R., Dixon, G.L., Rowley, P.D., and Brickey, D.W., 2005, Geologic map of parts of the Colorado, White River, and Death Valley groundwater flow systems, Nevada, Utah, and Arizona: NBMG Map 150, map and text.

Rowley, P.D., Nealey, L.D., Unruh, D.M., Snee, L.W., Mehnert, H.H., Anderson, R.E., and Gromme, C.S., 1995, Stratigraphy of Miocene ash-flow tuffs in and near the Caliente caldera complex, southeastern Nevada and southwestern Utah: in Scott, R.B. and Swadley, WC, eds., Geologic Studies in the Basin and Range - Colorado Plateau transition in southeastern Nevada, southwestern Utah, and northwestern Arizona, 1992, U.S. Geological Survey Bulletin, 2056-B, p. 43-88.

More Photos of Hoodoos:
Hoodoo, New Mexico at About.com Geology

Time Almost Beyond Imagining: Who Do the Magic that Hoodoo? at Geotripper

Hoodoos Redux: What I'm Reading at Geotripper

Limestone Hoodoos, Bryce Canyon National Park at Rosetta Stones

A Change in Weather: Fall becomes Winter?

2009-10-01T10:00:00.000-07:00

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.
This closer view of the Duck Creek Range, with Camel Peak to the right, shows the aspens better - a yellow to red patch to the right of the central saddle, just above the folded Cambrian limestone.
Two days later - Wednesday to be precise, because I shot this pic yesterday morning - there was snow on the mountain, and many leaves had fallen off the aspen trees. Today, the snow is mostly gone, except for some patches on north slopes under a few trees.
The same two photos, enlarged, for easier comparison.
Exactly one year ago yesterday, on September 30, 2007, I happened to be at the top of the saddle north of the aspen trees, and I took this somewhat faded-looking photo with my old camera. The same aspen trees - located just above the light gray Cambrian limestone and just below the pointy-looking peak, Camel Peak - had mostly dropped their leaves. Saddle location in Google Maps. Oh, and btw, that's an exposure of mylonitic quartzite in the foreground!

Ah, the vagaries of weather, year to year.

As for our garden, it experienced our first hard freeze (it got down to 14°F at the airport, but was already 39°F when I checked our thermometer at almost 9:00 am, and 32°F at the airport at the same time - we are in the banana belt). The tomatoes have wilted and are falling over, the leaves of our zucchini plant are lying flat on the ground, and the marigold leaves have wilted and turned blackish green. The kale is just fine, and so is the chocolate mint. Yay for the chocolate mint!

Garden Status at 17 Weeks

2009-09-30T08:48:00.000-07:00

Our growing season is just about over, and this is what our garden looks like after more than 4 months: a bit overgrown, kind of crowded (and this morning it's wet from overnight rain). For comparison, see 9 weeks, 5 weeks, and 0 weeks.
We've managed to get a few red tomatoes this summer, although our most recent ones have cracked while growing. We have tons of green tomatoes of all sizes, with the medium and larger ones also cracked. Possibly they grow too fast?

Our zucchinis got huge while we were away for two weeks - the scale in the photo has inches on the bottom, centimetres on the top. The zukes seem to either not grow large at all with rotting near the ends, or to grow fat, usually with rotting near the ends except for the two giant ones. Maybe we'll carve one for Halloween!

Our Anaheim peppers have grown exceptionally well with zero problems, and a few have now started to turn reddish on sides facing the morning sun.

The red kale looks good and has grown well. We stopped the caterpillar chomping of all the inner leaves by spraying water containing garlic and red pepper. Leaves we have eaten taste of garlic, and even the small ones take a long time to tenderize. A. Very. Long. Time. We'll try chard next year instead of kale.

A few links I came across while trying to avoid canning:
Drying peppers: UK Chile-Head
Freezing peppers: Learn2Grow
Storing peppers: UC Davis Publication 8004
Freezing greens: PickYourOwn.org
Freezing tomatoes: PickYourOwn.org
Freezing green tomatoes: NCHFP
Freezing food: NCHFP
Freezing vegetables: NMSU Extension Service

Date and time of photos: September 29, 2009, at 10:20 pm.

It's Not Too Late!

2009-09-29T11:02:00.000-07:00

Video created by The Sneer Review.

It's not too late to vote for GrrlScientist, who blogs at Living the Scientific Life (Scientist, Interrupted). She's in the running in the Blog Your Way to Antarctica contest, and has been endorsed by many. Tomorrow is the last day to vote!

Vote here! Vote now! It's not too late!

Meadow Valley Wash: the Narrows

2009-09-28T08:50:00.000-07:00

More than a week ago, I left you with this enigma of an outcrop, which occurs at the base of some tall, brownish cliffs at the south end of Rainbow Canyon in Meadow Valley Wash. As seen before, the cliffs show crude columnar jointing. Columnar jointing is often well developed in basalt flows, and similar horizontal joints can occur in basalt dikes.

We are in Nevada, however, where anything goes!
Taking a closer look at the exposure at the base of one of the cliffs, we see a reddish gray rock with some kind of bedding or flow foliation. My finger is pointing at a lithic fragment.
Just beyond the lithic fragment, we see a large, light gray, somewhat flattened pumice fragment. The layering in the rock, which is not really bedding, is from welding of this relatively crystal-rich, rhyolitic ash-flow tuff. The texture is known as eutaxitic, and it is the result of compaction during cooling and welding of the tuff. In this case, the tuff is moderately to strongly welded, not strongly enough to show consistent or strong fiamme as Andrew shows here.
Looking straight up from the base of the cliff, we get this view. The rocks generally become lighter toward the top of the cliff and above our view, with welding decreasing gradually in intensity. The lighter color of the upper part of the tuff can be seen best in my first picture of these cliffs, from my first post on our 1978 camp in Meadow Valley Wash. In that month-ago post, when I described the rocks at the base of these cliffs, I answered last week's question!
Large boulders of the lighter-colored, upper part of this ash-flow tuff have broken off and fallen from the top of the cliffs, and can be accessed easily along Highway 317. The upper part of the tuff - as seen in these roadside boulders - is moderately welded and shows compaction foliation (flattened pumice). The pinkish gray rock in my hand is a piece of this same tuff. Some of the larger boulders that fell from the upper part of the cliffs can be seen in the next photo.
Columnar jointing is fairly common in the more strongly welded portions of some ash-flow tuff formations in Nevada; they are often dark brown, dark reddish brown, or dark orangish brown. These columnar-jointed welded tuffs can be confused with basalt from a distance - and the two rock types can even be confused up close if you haven't broken open a rock or two. After gaining some experience with this phenomenon, you may become confident enough to pronounce some dark volcanic columns capping a distant hill as either ash-flow tuff or basalt - but without having seen geologic maps of the area or walked over to the outcrop, even an experienced person can get it wrong.
This ash-flow tuff is called Tt4 on this map. Tt4, which lumps several ash-flow tuff formations, is described here as including "poorly to densely welded, crystal poor, bimodal high-silica rhyolite and peralkaline ash-flow tuff and related airfall tuffs; gray, red, tan, and brown." The tuff in our cliffs is probably the 14.0 Ma tuff of Etna or the 12.6(?) to 11.4(?) Ma Ox Valley Tuff - dates are from Rowley et al, 1995.
The Ox Valley Tuff is "a light-gray, crystal-poor, poorly to densely welded, high-silica rhyolite ash-flow tuff whose outflow consists in most places of one to four cooling units that generally total less than 40 m thick but may be as thick as 130 m" (Rowley et al, 1995). Note that this description of "crystal-poor" doesn't match our earlier crystal-rich pronouncement. The description goes on to say that the Ox Valley Tuff contains 30 to 40% phenocrysts, which seems more than crystal-poor to me, but phenocryst percentage in an ash-flow tuff varies with degree of welding, and we are looking at a relatively densely welded part of this unit. The most abundant phenocrysts in the Ox Valley Tuff are sanidine and quartz. Plagioclase, amphibole, and clinopyroxene were noted in decreasing abundance, with trace to minor biotite.
About 75 m of tuff is exposed at our location, from the base of the cliffs to the base of the overlying basalt flows. With the base of the tuff not exposed - or with it exposed in the canyon somewhere to the north - the tuff may be as thick as 100 m or more in this general area.
After dinking around at the base of these spectacular cliffs, I turned my sights on the trees lining Meadow Valley Wash and scared up a deer.
I walked over to the running creek and got my feet wet once again.
After cooling off in the shade, I turned back toward the cliffs, which stand like sentinels over the partly washed out road.
I then headed back to my truck to continue my drive north in Rainbow Canyon, north toward Caliente.

Some References:
Page, W.R., Dixon, G.L., Rowley, P.D., and Brickey, D.W., 2005, Geologic map of parts of the Colorado, White River, and Death Valley groundwater flow systems, Nevada, Utah, and Arizona: NBMG Map 150, map and text.

Rowley, P.D., Nealey, L.D., Unruh, D.M., Snee, L.W., Mehnert, H.H., Anderson, R.E., and Gromme, C.S., 1995, Stratigraphy of Miocene ash-flow tuffs in and near the Caliente caldera complex, southeastern Nevada and southwestern Utah: in Scott, R.B. and Swadley, WC, eds., Geologic Studies in the Basin and Range - Colorado Plateau transition in southeastern Nevada, southwestern Utah, and northwestern Arizona, 1992, U.S. Geological Survey Bulletin, 2056-B, p. 43-88.

Friday - Back from the Road

2009-09-25T13:58:00.000-07:00

Yes, we are finally back at our little house, back from being gone for a whole two weeks, traveling back and forth between Reno and the lake - back and forth, back and forth - more times than I care to mention. We stopped in Middlegate on our return; hence the photo, looking to the east through the window and screen door of Middlegate Station toward Middlegate The Place. My mind feels just about as clear as the hills and mountains look.
The night before, Middlegate The Place, with the Shoe Tree visible through the notch, looked serene in the evening light, as the sun went down and turned the Desatoya Mountains red.
Looking the other way, West Gate showed no sign of it's usual windmill, which was still lying on the ground waiting for repairs when we drove through.

Care to make a phone call?

We had great burgers, decent to good beers, and played a few uninspired games of pool. The usual Middlegate drama was taking place in the bar, though we heard only bits and pieces, off and on.

I'm in some kind of muddle-headed state and somewhat incapacitated regarding decisions about travel - which courses and field trips should I take, what stops along the way should I make. I'm travel-worn and peopled out. (People-worn and traveled out?)

Above: Tangled, prickly, but still blooming (Russian thistle AKA tumbleweed ).

Prior to leaving two weeks ago, I had plans to visit yet another past field area in the next couple or three days, then non-finalized plans for side trips on the way to and from the coming GSA meeting. I have, today, been wondering about changing my GSA plans (once again) in order to make it to a poorly scheduled SEG field workshop on uranium deposits in Albuquerque, which would mean flying to Portland instead of driving, would mean leaving GSA two days early because the course overlaps with the meeting even though they call it "post-meeting," and would mean flying from Portland to Albuquerque and then flying back to some possibly nearby (or not) western airport.

Or, instead of that, I could go to an expensive field course on copper deposits in Arizona, which conveniently follows - by several days so as not to be too crowded in time and place - the Northwest Mining Association Convention in December. The copper course is run by people who know what they are doing. (Not that the uranium course isn't, mind you.) I'll probably do the latter (copper). I'd need to sign up for the uranium course today; I'll need to sign up for the copper course by next weekend. Besides, the price of copper is holding; the price of uranium isn't.

The sign said Middlegate, but where were we, really?

While crossing Eighmile Flat on our way to Middlegate, we were approached rapidly from behind by two flashing, wailing, Churchill County sheriff vehicles. They beat us to Middlegate by several minutes. Why were they there? Does anyone really know? Hopefully the answer will not be found in Stephen King's Desperation, which I am currently reading.

Other questions need to be answered - will I stay one night with a cousin on my way up to Portland? Will I spend more than one night at the lake on the way? Will I make an Oregon detour on my way back? Or should I just blow all that off and fly up to Alaska for about a week. Maybe I'll just stay here and stare at a wall until I regain some internal mental composure.