Looking For Detachment

I'm doing the year-end meme wherein I compile the first sentence of the first post of every month. Meme rules are as follows, as per DrugMonkey (2014):

Post the link and first sentence from the first blog entry for each month of the past year.

I also add the first photo from the same first post. Previous takes on this Twelve Month meme at LFD were posted for 2008, 2009, 2010, 2012, 2014, 2015, and 2016.

Aaand...here's the year 2017 for LFD:

January:
It's been icy cold in the far northlands, with temperatures hovering not too far above zero for several days.

February:
It was a late fall day, and I stopped along Route 447 to see if I could get close to some of the brilliantly colored trees along the Truckee River a few miles north of Wadsworth.

March:
I planned to have this descriptive section as part of the last post—the one about being packed and ready to leave town—but this "little bit" grew and grew, and eventually it had to find its own home.

April:
I was looking back through some photos and realized I had some of the Roan Cliffs from the spring of 2006.

May:

What is this?!!1?1!?

It all started when I was trying to find out what rock formations and rock types I was seeing while making the long trip to work and back out near Elko.

June:
I'm moving slowly on this mini-series about the Humboldt River while working essentially 12-hour days and while (hopefully) recovering from some long-lasting bug I caught on the road or out in Elko more than two months ago.

July:
Returning once again to my spring mini-series about all the rivers and lakes that are at higher levels than I've seen in quite awhile (most recent post), I decided this time to show a few pics of the Truckee River, which I drive by quite frequently.

August: Nothing.

September:
It's been a busy summer, such that I really haven't had time to get much blogging done—and I had so many good posts planned!

October:
This is a classic road song with "road" right there in the title, courtesy once again of MOH.

November: Nada.

December: (this post).
I'm doing the year-end meme wherein I compile the first sentence of the first post of every month.

Every time I drive Highway 6 between Idaho Springs and Golden, Colorado—and I almost always take that route when heading east, rather than the section of I-70 between Idaho Springs and the hogbacks—I try to get a few photos of the great gneiss forming the canyon walls. If I'm going eastward, it can be hard to stop because I'm almost there. This time, in the fall of last year, I was heading west, but I still found it hard to stop, partly because of traffic and unexpected road work. Nevertheless, I managed to make a few pullouts that were rewarding.

The first shot is typical of the biotite gneiss that underlies much of the region: darker bands with more mafic minerals, and lighter bands composed almost entirely of felsic minerals.

Here's a little more of that same biotite gneiss showing complicated deformation.

The geology of the area, seen below in a cutout from a USGS map, looks a little complex! Our first two photos (the two easternmost dots that are rather close together) are in what is mapped here as Xb: Proterozoic biotite gneiss.

Map courtesy USGS (Kellogg et al, 2008).

A little farther into Clear Creek Canyon, I pulled over and grabbed a couple shots of this second roadcut (single dot to the west, above), primarily because of all the light-colored dikes and masses. These rocks are probably what is mapped as Xh: hornblende-plagioclase gneiss and amphibolite.

All of the rocks we're looking at today are thought to have originated as sedimentary and volcanic rocks that were deposited in a basin 1780 to sometime after 1750 Ma (million years ago), as per this pamphlet accompanying the map.

A shot of the entire roadcut.

Somewhat darker gneiss is above somewhat lighter gneiss in this roadcut. The darker portions may qualify as amphibolite, which is part of the Xh unit.

The same gneiss, zoomed in a bit.

I noticed what looks like a little folding while I was processing these photos, so I drew in a few lines. The rocks look darker inside the fold nose, and there has been a lot of injection of the light-colored material, which might include felsic dikes like aplite or pegmatite, and also might include some quartz veins. I really don't know how common quartz veins are within these gneisses, and the roadcut is too close to the often busy, narrow and windy, two-laned U.S. Route 6 for safe examination.

If you want to see more of these rocks, here is Robin Rohrback's set of gigapans of the roadcuts along this stretch of Highway 6, along with gigapans of hand samples of the gneiss.

Reference:
Kellogg, K.S., Shroba, R.R., Bryant, Bruce, and Premo, W.R., 2008, Geologic map of the Denver West 30’ x 60’ quadrangle, north-central Colorado: U.S. Geological Survey Scientific Investigations Map 3000, scale 1:100,000, 48-p. pamphlet.

Earlier that day (the same day I stopped in Parachute and Rulison, resulting in three posts about the Roan Cliffs), I had pulled over at the convenient viewing pullout on I-70, which is east of Grand Junction and a bit west of Palisade. It's hard to pass by this cliff, part of the Book Cliffs, without taking a picture or two. This time, unlike most other times, I took only one photo!

The Book Cliffs are capped by sandstone and lesser shale of the Upper Cretaceous Mesaverde Group, which overlies shale and minor siltstone and sandstone of the Upper Cretaceous Mancos Shale. The Mesaverde Group (sometimes Formation, see Geolex) usually consists of several recognized sandstone tongues, members, and formations, with intertongues of Mancos Shale in its lower part. In the area of these photos, the mapped sandstone formation—the buff-colored cliff-former above the Mancos—is the Mount Garfield Formation, obviously named for Mount Garfield, the highest point above the cliffs, on the upper left.
I cropped the photo to zoom in, partly because the nearly white layer just below the sandstone cliff caught my eye. While here, we might as well take a peek at the geologic contacts.
Kmg is the Mount Garfield Formation; Km is the Mancos Shale. The contact I’ve drawn in is largely from the Geologic Map of the Clifton Quadrangle, Mesa County, Colorado (Carrara, 2001), with extrapolation from the Geologic Map of the Palisade Quadrangle, Mesa County, Colorado (Carrara, 2000). The contact very roughly approximates the one shown on the Macrostat online geologic map.

Other photos of mine of the Book Cliffs can be seen here (photos from 2006) and here (photos from 2008). Also check out Ron Schott's GigaPan of the cliffs.

I was looking back through some photos and realized I had some of the Roan Cliffs from the spring of 2006. These first two photos are taken from an impromptu campsite MOH and I found not far from the Rulison exit on I-70, and they somewhat approximate the views seen in Ron Schott's excellent gigapan of the cliffs. I'd embed the gigapan here, but Blogger seems to have some problem with either the iframe coding or the flash implied within the code (or maybe it's Chrome, and I'm being deluded as to what's possible). In either case, we're looking northwest toward the cliffs in the first photo (above), and northeast toward the cliffs in the second photo (below).
It was a very green spring, according to these photos, so the color balance doesn't match with my fall 2016 photos below, which were taken from near or at the Rulison exit. Also, my Nikon tends towards blue.
The reason I stopped for these particular photos during my semi-mega roadtrip of last fall was the talus. I found the striping caused by alternating zones of vegetated and non-vegetated slope areas to be fascinating in the way that perhaps only a geologist, geomorphologist, or photographer can. So I grabbed a few quick shots focusing largely on the talus slopes. More recently, I decided some approximated geologic contacts were in order.
In this photo (above), the cliff and talus slope below the cliff are formed on the Tertiary Green River Formation (Tg), and the colorful beds near the bottom of the photo consist of the Tertiary Wasatch Formation (Tw). The thin cyan line near the base of the cliff marks (hopefully) the top of the Mahogany ledge as extrapolated from this USGS preliminary geologic map, as deduced from this report (Fig. 9, p. 16)—which points out the top of the ledge in a cliff to the west—and as mapped from Ron's gigapan of the cliffs. A few other reports were helpful for exploring the general geology and reading some background info about the ledge and zone—it's called the Mahogany zone when intercepted in drill holes.
In this set of two photos, I've zoomed in on the striped talus section that was on the far right of the previous two photos. The vertical striping of the talus contrasts nicely with the horizontal layering of the Wasatch beds, don't you think? I've labeled the photos below. This time, a tiny bit of the Tertiary Uinta Formation (Tu) is barely visible at the top right. The stratigraphic contact between the Tg and Tw is crudely outlined in faded cyan: It crops out behind the foreground slope where we can't see it.

This set of two photos is not that different from the previous set, but here (below) I've sketched in the Mahogany ledge (as approximately extrapolated), and I've broadly labeled the geologic formations without drawing in the contacts. The circle is where an old mine, the Rulison Oil Shale Mine is shown on the topo map of the area  (USGS TNM 2.0 Viewer link). I can't see it there in the photo—though maybe it's just not apparent—but there is a tiny black area that *might* be an adit just beneath the arrow.
The cliffs in these 2016 photos lie northwest of the Rulison exit and occur between the first two 2006 photos.
In this last set of two photos, we're looking northeast from the Rulison exit, zooming in on cliffs that approximate what we can see in the second of the two 2006 photos. I once again focused in on striped talus, but then I really zoomed in on some switchbacked roads that I thought might be drill roads. It turns out that the switchbacks climb up to some underground workings into the Mahogany ledge, which I've marked approximately with a thin cyan line (below, with thicker lines marking formational contacts; Tu = Uinta Formation; Tg = Green River Formation). The line is taken directly from the previously linked-to preliminary geologic map of the Anvil Points Quadrangle (O'Sullivan, 1986). The map can be viewed directly in Google Earth, an option I always appreciate.

The underground workings here consist of several adits comprising the Anvil Points Oil Shale Mines. The mine was active intermittently from 1925 to 1982 (the last link includes some undated photos), with some clean-up operations running from 2008 to 2013.
How do you spell Talus-y? I see 3 options: talus-y, talusey, and talusy. I went with the first option in the title but prefer the last. Yes, I know it's not a *real* word.

After seeing Ron Schott's awesome and enlightening GigaPan of the Roan Cliffs, I decided I had to mark some contacts on the photos from my last post (and partly because what I said or implied about the formations were a little off). To deduce the location of these contacts, I extrapolated from this USGS preliminary geologic map, using the USGS TNM 2.0 Viewer and Google Earth.
In the first photo, it's still a toss-up, imo, as to whether the Tertiary Uinta Formation (Tu) can be seen—but if so, it's way up at the top of the cliff. Most or all of the cliff and most of the slope is underlain by the Tertiary Green River Formation (Tg). Aaaaand maybe there's a bit of the Tertiary Wasatch Formation (Tw) at the bottom of the photo.
In the second photo, there is (probably) just a tiny bit of the lower part of the Uinta Formation (Tu) above the cliffy area, and the reddish-brown foreground slopes are underlain by the Wasatch Formation (Tw). The rest, cliff and slope, consists of Green River Formation (Tg).

Getting back to my October-November road trip (last seen here), I stopped to get some fuel in Parachute, CO, on what was Day 7 of the trip, and I ended up taking a few photos (surprise!), partly thinking that the cliffs show good examples of bedding, and also because I was becoming fascinated by the exceptional talus slopes coming off the cliffs. The first photo is a cliff at a round nose sticking out from Mt. Callahan. The second photo is of a cliff at the southern end of a nose known as Allen Point, a long skinny ridge running about 1.5 miles south of a broader, arcuate area also called Allen Point.
When I investigated this area after my trip was over, I was surprised to find that these cliffs are part of the Roan Cliffs: while still enroute, I thought I was driving along the Book Cliffs. The Roan Cliffs are the cliffs that break south off of the broad Roan Plateau, a large plateau area that extends from Rifle, CO, to at least somewhere north of Grand Junction, possibly bounded on the west by Roan Creek. The Roan Cliffs, however, at least as shown here, encircle a broader area extending westward from Rifle, CO, to the mountains just east of the Wasatch in Utah.

The Roan Cliffs are capped by the Eocene Uintah Formation (which we may or may not see in these photos), and slopes below the uppermost cap are composed of the Eocene Green River Formation. Some of the lower, reddish slopes in the area are underlain by the Paleocene to Eocene Wasatch Formation. You can read a little more about the geology of the area in this USGS Bulletin.

The Roan Cliffs stratigraphically overlie the Book Cliffs, which we'll see later. I'm not sure how I mistook the cliffs of the Uintah Formation and upper Green River Formation for cliffs of the Cretaceous Mesaverde Group, or slopes of the Green River Formation for the usually easy-to-spot Cretaceous Mancos Shale. I can only plead that geology at 70+ mph isn't always spot-on.

This little post will serve as an introduction to the trip MOH and I took recently through parts of five western states.

It was a trip of views...

Looking south toward Zion from Utah S.R. 14.

And of new places.

Fog coming off volcanic rocks, as seen from Colorado S.R. 34, AKA Trail Ridge Road, AKA Highway to the Sky, in Rocky Mountain National Park.

Another view from Trail Ridge Road (with snow!) from above 11,000 feet, possibly from above 12,000 feet.

A trip with roadcuts...

On the road to Dinosaur National Park, from just outside Dinosaur, CO, looking south. Utah says this is Jurassic Entrada Sandstone on the Jurassic Carmel Formation. Colorado is vaguer about its formations.

And old roads...

Looking straight down old U.S. 40 (West Wendover Boulevard, Wendover, NV) from I-80 toward the Great Salt Lake Desert.

U.S. 40 in Utah, with an old alignment of 40 off in the bushes. (Which road did my family and I travel on in 1957?)

A trip over lots and lots of Mancos Shale, especially in UT and CO...

Mancos Shale just west of the UT-CO stateline near Dinosaur, with a bit of Mesaverde Group sandstone on top.

Mancos Shale, seemingly everywhere, looking south from U.S. 40 near Elk Springs, CO.

And a trip of wonderful cross bedding.

Navajo Sandstone along Utah S.R. 89 about 6 miles north of Kanab.

The map shows major locations or stopping points on the trip, not locations of photos.

The Accretionary Wedge for January, Pondering the Future of the Earth, is up at Clastic Detritus. Go read it so you know what's in store for the next 1 million plus years!

I'm a little confused about which number this is: either #15 or #16. It looks like it's going down as #15, though I put #16 on my entry, and can't change that now because it's already been linked to. Not a big deal, though - we're talking millions of years; what's a little number like 15 or 16?

The sign in the photo above is at the Rabbit Creek exit, Exit 2, on I-70 in western Colorado, not far from the Colorado-Utah border. The sign points to a 1.5 mile interpretive trail loop, the Trail Through Time, where you can hike to an old dinosaur quarry (that would be a quarry dug for dinos not by dinos!). Stop by when you get a chance! I was in a hurry to get to Fisher Towers, so passed it by this time.

While on the road over the holidays, I had the great good fortune to meet two bloggers on my way through Colorado.
The first was ReBecca from Dinochick Blogs. We met at a Starbucks and chatted for a couple hours. Above: ReBecca in Starbucks. I'm the one taking the photo (ha!).
I also met Wayfarer Scientista, a self-proclaimed
"ologist" and wanderer. Having never met an ologist before, I had quite a lot to learn about ology. We had some great times wandering around her mystery town and thereabouts. Above: Wayfarer and I with a "paint" background. I can't hardly tell us apart in this photo, and, as you can see, we both favor gray and have almost identical hair. Amazing!

Anyway, thanks to both of you for taking the time to meet me. Hopefully we'll meet again!

Posting and commenting has nearly fallen by the wayside while I sit and bask in the sun and clouds and wind of the Rocky Mountain Front Range. So far, I still haven't climbed up to the base of the giant Flatiron outcrops, not only because the visiting schedule here has been intense, or at least full, but also because I have caught one of those nasty holiday viruses. This one may have come all the way from Alaska, or maybe it came from Nevada, Utah, or Colorado! Hopefully it will be in retreat by the time I need to head back home.
I've had some nice relaxing times sitting by the tree and gazing out the window...
...and have also gotten out and about a bit. The tree above was in the two-story lobby of the Hotel Boulderado, a fancy old European-style hotel and a great place to eat.

Hope you all are having good holidays!

As you can see by comparing the photo taken a couple days ago, above, to the one taken in early summer a couple years ago from a slightly different angle, here, The Flatirons look about the same. There is the addition of a bit of snow, which can be seen mostly in the foreground, and the subtraction of a few clouds. I suspect some snow is hiding under trees, in gullies, and behind rocks in the background. Quite frankly, I expected a lot more snow.

So far I haven't had the chance to walk up to the rocky outcrops, but have instead been resting, visiting, and getting ready for last-minute shopping.
Here in the suburbs, we had less than a skiff of new snow last night, which fell on patchy old snow and ice.

Compared to the last time I drove by the Book Cliffs near Grand Junction, Colorado, a couple years ago (photo here), there was indeed a bit more snow when I drove by a couple days ago, although the snow was not deep.
The Book Cliffs are formed from a resistant sandstone in the Cretaceous Mesaverde Group - the two buff-colored cliffs at the top of the slopes above - which cap badlands formed on the Cretaceous Mancos Shale - the brownish to gray slope-forming unit below the capping cliffs. The Mancos Shale is fairly easy to recognize as you drive over it on I-70 in eastern Utah, because it is made of coaly beds and swelling clays, the latter of which cause the roadbed to become quite bumpy in places.
Above, a bit of detail in the Mancos Shale. Driving through the area from the San Rafael Swell into eastern Colorado always reminds me of the paintings of the artist Georgia O'Keeffe, who painted desert scenes and badlands, especially in New Mexico.