Winnemucca to Hwy 395 north of Susanville, Part4

And now we’ll say goodbye to the Smoke Creek Desert, which we saw on the last leg of this cross-country journey, and make our way south for a very short distance, where we’ll turn off the road skirting the entire west side of the desert, and head west up Smoke Creek. Photos you’ll see in this blog post are from three different trips taken between the Smoke Creek Desert and Highway 395 during May through August of 2006, 2014, and 2015. Which means that although we’re returning to my June 15, 2018 trip from Winnemucca to Susanville, which began here,I didn’t take any photos during this section of the 2018 trip.

Immediately upon leaving the great tufa mounds of the last post, we come to a hill with a view of distant trees that are growing along lower Smoke Creek. The sign indicates our upcoming turn onto the Smoke Creek Road. The smaller, hand-painted white sign says “Smoke Creek Road,” so we know we’re on the right track. (Photo: 17May2014.)

On the left side of the road, just as we turn right, a bullet-ridden sign points south toward Sutcliffe, a small town on the west side of Pyramid Lake several miles beyond our turn. This will be our last view of the Smoke Creek playa and the Fox Range to the east. (Photo: 14Jun2006.)

We’re now heading about due west toward the valley of Smoke Creek. In this area, a lot of the creeks and canyons are named on USGS topo maps, but very few of the hills are. As an example, the highest point on the volcanic-covered hills above is merely marked with an X and the elevation 6186 feet, along with a small triangle for a survey point with the name Smoke. (Photo: 17May2014.)

Smoke Creek Road

US 395 Jct 30

Litchfield 39

Susanville 55

(miles)

The basaltic hills, and the sagebrush in the foreground, were fairly green in mid-June of 2006. The buff-colored hills are underlain by Lake Lahontan lake deposits, possibly the Sehoo Formation, which are inset into the older, Miocene basalts. (Photo: 14Jun2006.)

We’re about to round the bend and drop in the valley of Smoke Creek. (Photo: 17May2014.)

Here you can possibly get a better idea of the younger lake sediments being inset into the canyon, such that although the buff-colored deposits are lower in elevation than the reddish brown basalt flows, they are not underlying them in a stratigraphic sense. This hill also shows the first example of Lake Lahontan tufa plastered on basalt (pale brown tufa on dark brown basalt in the upper left part of the photo). (Photo: 17May2014.)

The older sediments that underlie the basalt have been baked to a bright red color in this view not far up the canyon. (Photo: 14Jun2006.)

And there’s more! A large mass of light brownish tufa sits atop vaguely spheroidally weathering dark brown basalt. For locations of these photos, check out the map linked near the end of the post. (This and next photos from 15Aug2015.)

Less than a half mile from the sharp turn near the west end of the canyon, we come upon the “Cave in Smoke Creek Canyon,” which is along the Nobles Trail section of the California Trail.

“There is a cave ... in this canon, the entrance of which will admit a man on horseback several of the company having entered on horseback but I do not think that they saw much for it was dark as pitch in the cave” – Mary C. Fish, Sep 7 1860

The signs along the various trails are maintained by Trails West. A photo tour of the trail can be found on their website here.

Our first view of the mouth of the cave, as seen when coming in from the east.

A closer view.

The cave with wild roses in bloom. (This and next photos from 17May2014.)

The cave has plenty of room overhead, and people obviously camp within. The roof is darkened by soot from many fires over the many years.

The view from the cave.

Across the creek from the cave, I spotted a cinnamon teal

to be continued...

Google Maps location map.

Related Posts:
Winnemucca to Hwy 395 north of Susanville, Part 3
Winnemucca to Hwy 395 north of Susanville, Part 2
Winnemucca to Hwy 395 north of Susanville, Part 1
Things You Find in the Field: Sulfur at Sulphur
Blue Mountain (2012)
Pulpit Rock (2012)
Smoke in the Black Rock & Smoke Creek Deserts (2102)
Where in the West: Black Rock Desert (2008)
Where in the West - June: A Second Look (2008)
Where in the West - June (2008)
Name That Place (2008)

Across the West and Back Day 2: A Hike along a Limestone Ridge

Where were we? Oh yes, it was *still* day two of our giant western loop trip (as I have so fondly labeled it), and we were at the Grassy Mountain Rest Stop, and we were about to take a hike through a bit of limestone.

The first stop on the short hike is a small window in limestone of the Pennsylvanian Oquirrh Group that may be equivalent to some part of the Ely Limestone (judging by its air-photo outcrop pattern alone — I haven't looked for diagnostic fossils). The online, interactive Utah geological map isn't specific to formation in this part of Utah.

Small window in limestone, looking south.

Same window looking back toward the rest stop, with MOH's hand for scale.

View to the west or southwest from our limestone ridge.

While hiking along the trail, the portion of the Great Salt Lake Desert that we crossed between Wendover and the rest stop was just barely visible through the haze. It's not that first white line out there before the rocky hills in shadow; it's the vague flat area beyond the shadowed hills on the right.

The trail continues to the south between two ribs of limestone, amidst the cheat grass and halogeton.

The view looking south toward unnamed hills, also underlain by Pennsylvanian limestone.

Pack rat midden in tiny cave.

We speculated about the formation of the limestone window, and wondered if something as mundane as a packrat's midden could have contributed to creating a small cave in the limestone, with uplift and erosion later leaving the window isolated from most of the exposure.

Trail's end. A part of the Cedar Range in the distance on the left; the unnamed hills seen earlier on the right.

Once again I've added the locations of these photos to the day's trip log (map) embedded below.

View Day 2: Elko, NV to Vernal, UT in a larger map.

Geology on the Road: Breccia with Flow-Banded Rhyolite

The other day, we looked at some flow-banded rhyolite, beginning at the vertical fractures near the fence on the left side of this photo, and ending on top of the knobby hill overlooking the corral. Warning: we won't see much flow banding, if any, today, but its still there. We will, however, find out why we stopped here while on our way to somewhere else. For scale, the log forming the top of the corral fence is about 5.5 feet above the ground. Location: near Middlegate and The Shoe Tree, just north of Highway 50 (Google Maps, Google Maps Street View, MSRMaps).
This mass of breccia in the center of the exposure immediately caught our attention, but we stopped to examine the caves, and only after stopping noticed the breccia. Note the bird nest, possibly an owl's, on the upper flat surface. And note the several caves, with MOH for scale climbing up to check one of them out. You'll also want to note that about waist high on MOH, and over to the right just before the rightmost vertical fracture, you can see a large dark patch or two. These are breccia fragments.
The inside of the upper cave: a good place to find pack-rat middens and small bones.
The largest, uppermost breccia fragment is about 2.5 feet in length and perhaps a foot or more wide. It appears to be surrounded by small fragments, with another large fragment below it to the left. I didn't try chimneying up the fracture to check them out in more detail, so we'll have to rely on this crude description.
In the main exposure to the right of the caves, large breccia fragments are within reach of even short people like myself. Besides the large, dark brown fragments to the right, you can see several small fragments near my hand. The breccia fragments consist of angular to subrounded pieces of rhyolite, which are set in a matrix of smaller fragments.
This large fragment shows what looks like volcanic flow banding or hydrothermal streaming around the right side of the fragment. I suspect that more than one type of brecciation might be exhibited at this outcrop. Candidates include primary volcanic brecciation, brecciation associated with caldera formation, and tectonic brecciation associated with faulting. Another candidate is hydrothermal brecciation.
Here's another example of what the matrix looks like, closer to that first exposure of flow-banded rhyolite from the other day, and visible as a large bright orange spot near the fence on the left side of today's first photo. At first glance, this pale to dark yellow orange to dark yellow brown mass looks like a clast or breccia fragment, but I think what we're seeing is a weathering phenomena, with a piece of the outer, dark brown weathering rind broken off, exposing relatively fresh rock beneath. We can see some light gray veinlets of silica shooting vertically through the yellow orange mass, and there are hints of large fragments cut by small veinlets. The next picture shows a portion of the rock to the right of the middle silica veinlet.
The rhyolite is fractured, possibly brecciated or at least crackled, and shows moderate iron-oxides, mostly goethite and jarosite.
A closer view shows a lot of very fine-grained to microcrystalline light gray silica that forms a matrix around tiny breccia fragments, or has at least replaced an earlier volcanic matrix. Possibly some of the brecciation seen in this exposure is hydrothermal. I recommend petrographic work to get down to the nitty gritty and to really understand what we're seeing.
From the top of the knob, we see the main road north into the central part of the Clan Alpine Mountains. We'll drive up there later, and make a sharp right turn in about a half mile, not far past the second little bend.
And lo, there's Fairview Peak off to the southwest, visible through two knobs of lichen-covered flow-banded rhyolite and rhyolite breccia. Middlegate Station is behind the knob on the right. Will we make it beyond Middlegate Station to Fairview Peak?