Twelve (or Ten?) Months of LFD (2017)

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.

Pine Valley and Carlin Canyon Squiggles

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. Looking around, I found this geologic map (Smith and Ketner, 1972), which even had a kmz file so I could load it directly into Google Earth—and so I did.

There I was, fiddling around looking at rock types and contacts. The map wasn't easy to look at in Google Earth (GE) because it was in black and white, so I started drawing the contacts on to GE, and lo and behold, the contacts were all screwy. It took me a while to figure out that the kmz file didn't register properly on GE; perhaps it didn't have a NAD27 to WGS84 correction or some such thing. I plotted a few static, known localities that I could identify on both the map and GE and determined that everything was off in a northwesterly direction (map to GE) by about 1500 to 1900 feet.

The map and GE locations of a small dam and the ghost town of Palisade.

I thought Palisade looked occupied the last time MOH and I visited, which was in the summer of 2013 (it was the only time either one of us has ever been there), so I was surprised to find it listed by search engines as a ghost town, rather than as a "census-designated area."

I was frustrated by this mis-registration of the map on Google Earth—what is the point of a kmz file of a map, after all, other than to be able to use it easily and forthwith—so I continued drawing on a few contacts in the area I was initially interested in: the area near the small (or old) dam shown above.

Oh look, there's a huge landslide or slump block mapped! I always find these fascinating, so I zoomed in on that, after figuring out that, indeed, I had stopped along the road once—in a pullout near the dam—and had found ash-flow tuff in the roadcut, just like I had remembered! (Although in this case, it was probably slumped or slid ash-flow tuff rather than 100%-in-place ash-flow tuff.)

And then I remembered that I'd always thought there was a pediment in Pine Valley, and recent drives through the area seemed to confirm that, though I wasn't sure if it would be considered a pediment because it seemed to be formed on Quaternary-Tertiary sediments. A couple of old reports (Regnier, 1960 and Eakin, 1961) confirmed that a pediment (or two, even!) had been identified in the valley—and that's when I went nuts with my GE squiggles, and started drawing in all the Quaternary gravels so I could better visualize the valley's geomorphology. That resulted in the squiggles seen in the first image: an incompletely labeled map with missing contacts but with pediment gravels outlined in great detail.

Then, I moved up to Carlin Canyon and—unsuccessfully in my opinion—tried to plot the unconformity contact. (See Ron Schott's Gigapan of the Carlin Canyon unconformity here.) And then I moved to the Carlin Formation east of the Carlin Tunnels. The Carlin Formation forms golden-brown outcrops and cliffs right alongside the highway, great examples of tafoni weathering, so close but inaccessible. I wanted to see if any roads led into the area, and there are none, but I drew some squiggles for the geology in that area anyway, and then moved south of the highway to draw in a few more areas of the Carlin Formation, because once I've started on something, it's hard to get me to stop.

An expanded version of my GE squiggles.

And that's what it all looks like at this point. Hopefully I'll be able to grab a few great photos of the pediment surfaces later this summer, when I move back into the area for another round of work way out there.

By the way, the completed geologic map (Smith and Ketner, 1978), published in color, can be viewed here (but without a kmz file).

More From the Road: Tilted Every Which Way?

I stopped while driving through the Virgin River Gorge in northwest Arizona to take this picture of some of the dipping sed rocks that are common through the greater Colorado Plateau area. (This area, lying barely within the Basin-and-Range province, is just outside the Colorado Plateau proper, but the rocks here are correlative to those throughout the plateau region, and they have been subjected to some of the same tectonic forces.)

It looks like the sedimentary layers are dipping every which way!

This second photo zooms in just a bit, focusing on the far hill, which shows a slight bend in some of the layers.

I've drawn in a few of the beds, as before, and point out a dip slope formed on the top of the reddish layer.

This Google Earth image of the area shows the photo location in purple.

I decided to see whether the beds were really dipping every which way. I used beds I could identify in Google Earth, picked out two points along the beds that were at the same elevations, and drew strike and dip symbols from these two points (method described here). The dip slope labeled above is the small lens-shaped hill beneath the central strike-dip symbol. It became apparent from looking at Google Earth that the primary reason the dips in the photos look cattywampus is because the rocks in the foreground are dipping toward the photographer (to the WNW), and most of the other beds are dipping in a more northerly direction (NW, N, or NE).

The same Google Earth image with some hypothetical strike-dip symbols.

So, how did I do on the strikes and dips? And is there anything else going on in the area? Well, okay (ish) and yes.

Map I-2165 (Bohannon et al, 1991) courtesy USGS, overlain on Google Earth.

The Cedar Wash high-angle reverse fault cuts right through the area, separating the strata dipping toward the west (the foreground strata in our photos) from strata dipping in a northerly direction. You can see, by clicking on the several images and going back and forth between them, that I did well on the strikes on the west and east, and not so well (in general) on the strikes in the center. Either that, or the strikes of beds in the center varies more than shown on the map (I'm pretty sure I did pretty well on the labeled dip slope, but I will never climb that hill to check it out!)

Read a little about the Cedar Wash fault and the general geology of the region here.

Titus Canyon Road: A Little History and a Few Maps

Now that we've arrived at Red Pass, and we've even taken a little hike, let's stop, absorb the view, and reminisce a bit.

The view west from Red Pass.

My experience with Titus Canyon probably dates to the early or mid 1980s when I was working for Former Mining Company down in the Mojave Desert of California. At that time, my minerals exploration work consisted of operating and running reconnaissance and project work, the latter of which generally consists of geologic mapping, surface sampling (rocks, soils, stream sediments), an occasional geophysical survey or two, and drilling (back then, all the drilling I did as part of gold exploration and evaluation was RC drilling, see more here).

Over the years, I've used the road into and through Titus Canyon mostly to get from here to there by way of a more scenic passage, a route that runs close to the geology (sometimes within arms reach). This alternative course can't really be called a short cut because the main roads into the Mojave, 95 and 395, are usually more direct and almost always much faster. Because of Titus Canyon Road's relative inefficiency in getting me to my destination, I haven't driven it more than a handful of times over the past three-plus decades, and two out of those maybe 5 to 6 total times have been within the last ten years. Back in the day—when I took this out-of-the-way "short cut" mostly from Beatty, Nevada, to Baker, California, when I was likely heading for Baker (yikes!), Barstow, or Ridgecrest—I generally drove the road alone in a half-ton, 4WD Ford pickup truck with a regular cab and full length bed. (I may have driven the road once or twice with a field assistant as passenger...maybe.)

“Short cuts make long delays.”
– J.R.R. Tolkien, The Fellowship of the Ring

My present-day impressions of the road and canyon are probably heavily biased by whatever state the road was in back then, and perhaps they are affected by the relatively long wheelbase of the truck I was driving. At least in my imperfect memory, Titus Canyon Road (the TCR) was largely untraveled back then, meaning that on the entire one-way trip (which, like I said or implied, I usually made as quickly as possible with very few stops because I was on my way to a destination still a few to several hours distant) I doubt that I saw as many as four vehicles—and I really don't remember seeing more than one or two. In other words, the TCR was a back road that few people knew about, or if they did, they didn't bother to use it. The road was only for true Death Valley or Saline Valley aficionados (the road to Saline Valley is a real 4WD road, one not to be scoffed at, while the TCR rarely requires 4WD, depending on one's vehicle and off-road skill level).

As you know if you've been reading my recent Death Valley blog series, the last time I went down the TCR was with MOH back in late February of this year. There were several vehicles parked at Leadfield when we arrived, and there were many more vehicles quite a ways behind us (I was driving relatively fast on the road, once again trying to make it through to reach a particular destination: the superbloom down near Badwater). I just don't recall the road being so heavily traveled back in the 80s, when I probably would have been on it mostly in December through May at the latest.

“I met one other fella' on the trail...”
– Ronald Swartley, 26 'spilling' miles to Death Valley, Am Motorcyclist (1978)

Note: I would personally hesitate to drive the road from mid May through sometime in October, November, or December (depending on the local weather) without a SPOT, which of course we didn't have back in the 80s. An equivalent type of safety backup back then might have been a car phone, although I personally had very poor luck with such a device in the late 80s down near the fairly populated (by Nevada standards) area of Victorville, Apple Valley, and (ugh!) Lucerne Valley (link to a great description of the seedy place at the Urban Dictionary; matches my remembrances of that sh**hole to a T).

My memories of the TCR center mostly around the awe-inspiring views from the heights of Red Pass and the incredible twisting, winding, and dropping of the road into the valley at Leadfield. The curves seemed tighter in a full length pickup than they do in a Jeep (or the current road is wider). My clearance over the rocks on the final steep pitch approaching Leadfield has always been fairly good, but I may have had to dodge them a little more assiduously back then (I wonder if the road was maintained as frequently?). Most recently, I've been surprised both times at the length of the first section of the trip, from the pavement of Nevada S.R. 374 to the apex of Red Pass. Oh, and of course the slot canyon near the end has always been fun. It's become quite a popular hiking area, something I don't really recall from earlier days, either. Another Note: the NPS say the Titus Canyon road is the most popular backroad in Death Valley National Park.

A cabin at Leadfield.

I regret, once again, that I haven't ever stopped to get a photo of the worst section of the road, the bedrocky part where you have to dodge a few rock masses sticking up out of the road in quite an inconvenient fashion, but I'm usually too busy driving...and dodging...and then it's over.

While doing a little research for this rambling post, I stumbled across a factoid previously unknown to me. As recently as 1978, Red Pass was known by some, including the National Park Service, as Bloody Gap—presumably because of the red color of the rocks rather anything because of anything nefarious in its history. I first noticed Bloody Gap being used in the caption of this old postcard [no longer available]. It was mentioned in this descriptive bit about Leadfield in Desert Magazine (1968), in this L.A. Times article (1969), and in this American Motorcyclist story (1978). The USGS, however, doesn't list Bloody Gap as an alternate name for Red Pass.

On my way to finding every mention of Bloody Gap that I could (including a few more links to selling old postcards on Ebay or what-have-you), I looked at old maps to find Bloody Gap, and also to see if another old name for part of the canyon, "Lost Canyon," was ever published.

By 1954, the TCR was shown as one way.

1954 Death Valley 1:250,000 sheet, courtesy USGS

And in 1961 and 1964, Titanothere Canyon was shown as "Titanother Canyon."

1961 Death Valley 1:250,000 sheet, courtesy USGS.

In 1985, the 30x60 Saline Valley map showed Titanothere Canyon (with an "e" at the end) and Red Pass. No Bloody Gap. No Lost Canyon. There was, however, quite a gap in map making between 1964 and 1985!

1985 Saline Valley 1:100,000 sheet, courtesy USGS.

For reference, here's a bit of the most current 7.5' topo map with everything as we know it today:

1988 Thimble Peak 1:24,000 map, courtesy USGS.

We'll be dropping from Red Pass into the eastern branch of Titus Canyon next time.

Related Posts:

Beatty: Old Buildings, A Fold, and Onward toward Titus Canyon

The Approach to Titus Canyon: Amargosa Narrows, Bullfrog Pit, and the Original Bullfrog Mine

Mineral Monday: Close-Ups of Bullfrog Ore from the Original Bullfrog Mine, Nevada

The Approach to Titus Canyon: Tan Mountain

The Approach to Titus Canyon: Up and over White Pass

The Approach to Titus Canyon: To Red Pass

The Approach to Titus Canyon: Just Below Red Pass

A Hike at Red Pass, Titus Canyon Road, Death Valley, CAcu

Approach to Titus Canyon: To Red Pass

It looks to me like you can see Quail Rock from White Pass!

We've gone over White Pass—btw, here's a gigapan looking west from White Pass—and we've gone across the flats in the east fork of upper Titanothere Canyon. The road has become a fairly normal dirt road, and although it's still a little narrow, there are places to pull over, or pass, if you happen to be traveling faster than someone ahead of you—although by this point on the road, there is plenty to look at, everywhere, all around, so going slow behind someone (back far enough not to eat any of their dust) is an acceptable option. All through this section, until about the unnamed pass between the east and west forks of upper Titanothere Canyon, the age of the rock formations is Cambrian to the south and Tertiary to the north. The unnamed pass is marked by "Gate" and a gate symbol on the USGS topographic map of the area (USGS TNM 2.0 Viewer)—not that I noticed a gate.

The geology changes a little at the unnamed pass, and the road goes into a series of curves, while also going up and down quite a bit. We've entered the territory of the Tertiary Titus Canyon Formation. The exposures right along the road from here to Red Pass will be either Titus Canyon Formation or Cambrian formations, though not much of the latter, and none that I have photos of.

This photo looks up the western branch of the western fork of upper Titanothere Canyon (Titanothere Canyon is not actually divided into forks and branches, but I've got to call them something!). A fault runs up this canyon, dropping the Tertiary section downward on the northeast (right) side.

You can see the southeast-northwest trending fault in this geologic overlay I made on Google Earth (G.E.). The geology is from Niemi, 2012. Using the "Add Path" feature of G.E. creates lines that hang up in the air above the topography in places, making the contacts as drawn look a little ragged. They also disappear behind topography, going in and out unexpectedly in places, so they are best used for quick visualization. My drawing of the contacts may not be precise, as Niemi's geologic map wasn't associated with an air photo (as published, anyway), and his topo base was digitized somehow, so it doesn't correlate directly with USGS topographic maps (TNM 2.0 Viewer), which can be directly correlated with air photos. I also may have modified some contacts based on what I was seeing on the air photos (G.E.).

Here, above and below, we can begin to see a little of the geology, including a lot of Quaternary alluvium (Q). Notice the terraces of older alluvium, especially the nice one up the canyon. And, by the way, I use blue for faults.

I've labeled the foreground units, from EOgtc to Q (Quaternary undivided). I've emphasized the southeast-northwest trending fault I mentioned earlier by thickening the blue line to the right of the little canyon we're looking up.

Most of these formations were described in a little detail in my last post. Briefly, the Trp is the Miocene Rhyolite of Picture rock, a rhyodacite to latite flow; the Tw is the Miocene Wahguyhe Formation; the Tg is the Miocene Panuga Formation; and the EOgtc is the latest Eocene to Oligocene Titus Canyon Formation. What is shown as Tg in these posts (and on Niemi's map) was once considered to be the upper part of the Titus Canyon Formation, a section known as the Green Conglomerate facies, which sits atop a disconformity on the Variegated facies of the Titus Canyon Formation, formerly considered to be the middle unit of the Titus. All that changed with the publication of Snow and Lux's Tectono-sequence stratigraphy of Tertiary rocks, California and Nevada in 1999, when the Green Conglomerate facies was assigned to the Panuga.

Below, you can see the sort of thing one can work with if geologic contacts are transferred to Google Earth.

This map is a small portion of Niemi's 2012 geologic map of the central Grapevine Mountains.

This image overlays Niemi's map (above) fairly well. I'm sure there is some distortion, and I didn't mean to leave my photo locations turned on!! I've extended a fault or two based on the air photo imagery in G.E.

Not far past this stop, beyond the sharp curve shown in the second photo and the images above, the road crosses a fairly major fault. (This fault is shown as "Fault Zone" in the portion of Niemi's map shown above; it's actually labeled "Fall Canyon Fault Zone" on the full map. I'm not sure if that is really correct, since the Fall Canyon Fault is actually in Fall Canyon, quite a ways to the west. Possibly this fault is considered part of a much larger Fall Canyon Fault Zone: It is parallel in part to the Fall Canyon Fault. (There are at least a couple "drafting" boo-boos I noticed on the map, besides this possible glitch. Labeling and coloring mistakes on published maps is really not uncommon, if you look closely.)

We're getting closer and closer to Red Pass. MOH and I decided to pull over in a slightly wide spot near the next curve so we could hike around a little and look at rocks. I took the next photo just before that curve, primarily to grab a shot of what appears to be an example of two normal faults forming a small, asymmetrical graben on the hill beyond the curve.

Is this a small graben?

A closer view of the hypothetical graben.

The top of the crystal tuff (xtl tuff) formerly marked the change from middle Titus Canyon Formation to upper Titus Canyon Formation. This generally greenish formation is now assigned to the Panuga Formation (Tg).

Looking around from various angles on Google Earth, I have to conclude that there is definitely something going on up there, probably more than two intersecting joints, although the offset on both structures is quite small.

The two hypothesized faults, as seen from a different angle thanks to G.E. The lower, lighter cyan line marks the base of the crystal tuff seen in the last photo.

The crystal tuff has been correlated with the 15.7 Ma Tuff of Unconformity Hill (Snow and Lux, 1999).

A bit of the Titus Canyon Formation, I'm not sure which part.

Here's a nice piece of gneiss (yes, we geologists really say things like that), a boulder that was once a rounded clast, probably in the Titus Canyon Fm, but possibly in the overlying Panuga Formation. "RUB" in Rubicon for scale.

From this same spot, we get a great glimpse of our next section of road: the climb up Red Pass.

We're looking in a southerly direction at the main switchback going up Red Pass. You can see why it's called Red Pass!

The road through here is in the Variegated facies of the Titus Canyon Formation, according to Lengner and Troxel (2008). I'll have to trust them on this. It is within the lower portion of the Variegated facies that late Eocene to early Oligocene fossils have been found (Lengner and Troxel, 2008), including the fossil Titanothere (Protitanops curryi) for which Titanothere Canyon was named. Read more about the Titanothere and other fossil finds here at Geotripper.

With this next photo, we've begun to climb the east side of Red Pass. We turn back around, after pulling over to the side, to see where we've been. The unnamed pass is right at that little white bit of road nearly at the center of the next photo. Just below that section of road, you see the Cambrian part of the latest piece of our journey: The jagged reddish brown rocks on the right side of the photo (south) are Cambrian Zabriskie Quartzite dipping northward (left), overlain by a thin, dark gray section of rock mapped as Cambrian Carrara Formation (although on G.E. the rock looks about the same as the Cambrian Bonanza King Formation did near White Pass).

We're looking northeast into the part of upper Titanothere Canyon.

With that view, we'll stop for now. We'll climb up Red Pass next time. While you're waiting, check out this great gigapan by Ron Schott, which looks like it was created at about the same spot I took the last photo.

A Few References:
Lengner, K., and Troxel, B.W., 2008, Death Valley's Titus Canyon & Leadfield ghost town: Deep Enough Press, 175 p.

Niemi, N.A., 2012, Geologic Map of the Central Grapevine Mountains, Inyo County, California, and Esmeralda and Nye Counties, Nevada: Nevada, Geological Society of America Digital Maps and Charts Series, DMC12, 1:48,000, 28 p. text.

Snow, J.K., and Lux, D.R., 1999, Tectono-sequence stratigraphy of Tertiaryrocks in the Cottonwood Mountain and northern Death Valley area, Californiaand Nevada, in Wright, L.A. and Troxel, B.W. eds., Cenozoic basinsof the Death Valley region: Geological Society of America Special Paper 333, p. 17–64.

Location map

Related Posts:
Beatty: Old Buildings, A Fold, and Onward toward Titus Canyon

The Approach to Titus Canyon: Amargosa Narrows, Bullfrog Pit, and the Original Bullfrog Mine

Mineral Monday: Close-Ups of Bullfrog Ore from the Original Bullfrog Mine, Nevada

The Approach to Titus Canyon: Tan Mountain

The Approach to Titus Canyon: Up and over White Pass

Death Valley Trip, Getting There: Coaldale, Black Rock, Lone Mountain, and the Boss Mine

Onward! Onward! How far will we get this time?

Coaldale, as seen in August, 2010.

With Boundary Peak still in view, MOH and I rounded the corner at Coaldale Junction, and pulled in briefly at Coaldale. This particular ghost town, which was first a small mining town and later a roadside waystation with a tiny population, holds a few minor memories for me, dating back to my early days at Northern Exploration Company in the late 70s and early 80s. For some reason, it always seems like a depressing place to stop, and I can rarely bring myself to take a photograph or to get out of my vehicle to take a close look. This time was no different, so I've uploaded a photo I shot back in 2010.

A few miles on, we pulled in at Black Rock, a spot which may originally have been just a little prospect pit in some black chert of the Ordovician Palmetto Formation, but which is now a semi-convenient place to stretch your legs (although it doesn't really offer much cover as a pit stop, and the Millers rest area and the town of Tonopah aren't too much farther down the road).

Coming to Black Rock from the west, Google Street View.

Lone Mountain as seen from Black Rock, looking ESE.

From the south side of Black Rock, we had a good view of Lone Mountain beyond the playa and salt flat of the southwestern end of Big Smoky Valley. A tiny bit of the Weepah Hills is in shadow off to the right (west).

A closer view of the southwest to northwest side of Lone Mountain.

In this photo, the lighter colored rock formation toward the right (west) is the ЄpЄ Reed Dolomite, which, as I noted earlier, is usually listed as Precambrian or Precambrian to Cambrian, and sometimes as Cambrian only. Here it's on top of a thin, dark section of Precambrian Wyman Formation. Underneath the Wyman, and to the left (east), the Cretaceous Lone Mountain pluton forms the bulk of Lone Mountain.

A couple ways in which the Cretaceous may have intruded the Precambrian so sharply and neatly are developed by Maldonado (1984) in the explanation of his map of the Lone Mountain area. I personally think the contact is structural: a low-angle fault (detachment, anyone?), and, in fact, the area is noted as being part of the Silver Peak-Lone Mountain detachment system (Oldow et al, 1994) or Silver Peak-Lone Mountain extensional (or core) complex (Oldow et al, 2009). Also, this map shows the contact as a detachment fault  (Hulen, 2008, between pages 4 and 5). In the few places that I've seen the Wyman-pluton contact on Lone Mountain, I've noted shearing, faulting, or other complexities—and along the north and west side of Lone Mountain, the top of the pluton looks somewhat planar from a distance, and other planar features (jointing?) are apparent from some angles. If you're driving by, a good place to pull off to see these planar features (I'm really not sure what they are) is at the turnoff to the dirt road going to the northern Gilbert mining district a few miles east of Black Rock  (Google Maps location).

Google Earth image from the perspective of between Black Rock and the turnoff to the northern Gilbert district, and up in the air a bit.

Approximate mapped contacts of the three major rock formations, from Maldonado, 1984.

The same image with a few pink lines added.

I'm not sure what the pink lines represent, other than that they are supposedly entirely within the Lone Mountain pluton. They may be joints in the pluton; they may be Tertiary lamprophyre dikes, as on the 1984 map. Another possibility is that the intrusive-sedimentary contact is mixed, like it is on Mineral Ridge, where Wyman and intrusive rock alternate near or just below the detachment fault (or detachment faults). Or maybe all three possibilities come into play. These are just a few ideas to take with you if you happen to go hiking in the area.

Turning back toward the highway, I stumbled across a few interesting rocks.

Breccia.

The rock is a veined and brecciated chunk of Ordovician Palmetto Formation—chert or siliceous mudstone to siltstone. While walking around, I wondered what the remnant of an old mine dump was all about. Maybe this rock holds a clue.

Here's a zoomed in view of the same rock, focusing in on the quartz vein right and center.

The quartz vein contains brown blades of a relict mineral that has now gone to iron-oxide and silica. Possibly the mineral was calcite, and if so, the resulting mineral or texture is often referred to as "bladed quartz" or "bladed quartz after calcite," or more properly, "quartz [or silica] after bladed calcite." The texture can be indicative that you're in the right part of an epithermal system to find an economic gold or silver deposit. Most of the quartz after calcite I've seen has been crystalline; this silica is microcrystalline.

In fact, several smallish gold deposits have been found in the immediate area, and one has been mined (so far only one deposit has been considered economic).

The Boss mine, a small gold deposit mined in the late 1980s, can be seen just across the road from Black Rock.

A zoomed-in view of the open pit area of the Boss mine.

The Boss produced about 32,000 ounces of gold from 600,000 tons of ore (Diner and Strachan, 1994). That would mean the ore grade was about 0.053 ounces Au per ton (o.p.t). The other deposits, including the Black Rock zone, are described here and here, along with the geology of the Boss mining area. Gold is reported to occur mostly in both Tertiary rhyolites and andesites.

And that will be it for today!

Location map

Related Posts (in order of posting):
Death Valley, "Super" Blooms, Turtlebacks, and Detachments
Death Valley Trip, Part 2: More of the Badwater Turtleback Fault
Death Valley Trip, Part 3: Northward, and over Daylight Pass
Death Valley Trip, Getting There: Wave Clouds beyond the Sierra
Death Valley Trip, Getting There: A Hike to Pleistocene Shorelines

Death Valley Trip, Getting There: Walker Lake, Road Stories, A Bit about Copper, and Some Folds near Luning

Death Valley Trip, Getting There: A Jeep Trail, Folds and Cartoons of Folds, Even More Folds, and Boundary Peak

Death Valley Trip, Getting There: Highway 95, Redlich, Columbus Salt Marsh, and Another View of Boundary Peak

Selected References:
Diner, Y., and Strachan, D.G., 1994, Geology of the Boss mining area, Gilbert district, Esmeralda County, Nevada: Econ. Geology v. 89, no. 5, p. 1176-1182.

Hulen, J.B., 2008, Geology and conceptual modeling of the Silver Peak geothermal prospect, Esmeralda County, Nevada: unpublished report for Sierra Geothermal Power Corporation, 23 p.

Maldonado, Florian, 1984, Bedrock geologic map of the Lone Mountain pluton area, Esmeralda County, Nevada: U.S. Geological Survey Map I-1533, 1:24,000.

Oldow, J.S., Elias, E.A., Ferranti, Luigi, McClelland, W.C., and McIntosh, W.C., 2009, Late Miocene to Pliocene synextensional deposition in fault-bounded basins within the upper plate of the western Silver Peak–Lone Mountain extensional complex, west-central Nevada: Geological Soc. America Special Papers 447, p. 275-312.

Oldow, J.S., Kohler, Gretchen, and Donelick, R.A., 1994, Late Cenozoic extensional transfer in the Walker Lane strike-slip belt, Nevada: Geology v. 22, no. 7, p. 637-640.

Strachan, D.G., 1988, Economic geology and exploration potential of the South Boss prospect, Boss gold mine, Esmeralda County, Nevada: unpublished report on file at Nevada Bur. Mines and Geology, 11 p. and notes.

Death Valley Trip, Getting There: Wave Clouds beyond the Sierra

Our trip began like this, although I didn't get any photos the first day, as we drove south, then east, then south again under fabulous wave clouds. It began with a bit of a rumble: The Jeep went into a noisy, rattling shimmy upon reaching 45 mph, and we had to pull into a tire shop. We got the tires balanced, ate lunch at a local diner—a lunch that included two large, old fashioned chocolate milk shakes—and went on.

We drove south with the high wind aloft evidenced by continuous and co-mingling stacks of wave clouds coming off the long linear range to the west. The waves were stacked almost indefinitely out over the Honey Lake basin and beyond, where they were coalescing into a high, thick stratus layer.

Approaching the first Red Rock turnoff, with Peavine not yet in view, the lenticulars came into their own, at first disintegrating from a near mass into many wispy and shredded lenses, and then turning into three or more parallel roads in the sky: the primary wave off the Sierra Nevada and the Carson Range, the secondary wave perfectly parallel to the first and a little ways off to the east, and the tertiary and quaternary waves ... well, they were there, but they were beginning to merge together, or to merge with the primary and secondary waves off the Virginia Range—close in they would appear as individual sets of stacked waves, farther out they would pile up against each other in a kind of jumbled mass, and even farther still they would metamorphose into a fluffy, wavy blanket.

The way it looked, sans color, when we began our trip down to Death Valley, looking south near Reno or Carson, 27Feb2016.

A couple times, as we drove south and then east, I reached a state of mind that I first noticed a long time ago when flying in some airplane: In this case, sitting in a Jeep while effortlessly driving, I seemed to be standing still while the mountains, clouds, roadcuts, and other drivers moved—instead—around me, as though I was in the middle of some 3-dimensional movie with the props being rapidly changed for my benefit. When I feel this way in an airliner, it seems as though I'm not going anywhere; instead, I'm just in some giant, crowded box, and people outside, who I can't see, are somehow shaking the box to simulate vibrations and turbulence, while they also somehow roll a scenery tape by my window. Before I got on the plane, the props (buildings, streets, people, everything) made the place look like Reno; by the time I got off, all the props had been changed to make it look like Alaska (they changed the buildings, streets, and people, and added steeper mountains and maybe some snow).

At Dayton, we drove under the secondary wave off the Carson Range, which was now a vivid, grayed yellow, almost the color I associate with incipient funnel clouds.

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The cloud overhead was colored something like this.

A few tiny sprinkles hit the windshield of the Jeep, barely dusting it. The stacked lenticulars to the southeast, out over the Pine Nuts and beyond the river route to Ft. Churchill and Weeks, turned bright golden yellow, then faded to soft peach mixed with salmon, then faded even more to a soft pink. The distant hills past Talapoosa turned bright pink, lit by the last bit of alpenglow.

The river route from Dayton to Weeks (Weeks is the spot where the Carson meets Alt-95). The map is courtesy USGS. We didn't take the route, though it can be a nice drive. It can also be long and washboardy and is best driven during the day (unless you know the road).

Dark colors took over the skies as we turned SE onto the Ramsey-Weeks cutoff, and darkness set in. We drove into headlights, coming finally to a town we hadn't intended to stay in (we thought we would reach Tonopah the first night, but our delay at the tire shop changed our expectations). We had an average Mexican dinner, accompanied by exceptionally hot salsa and lackluster margaritas. We found a nice, cheap room and settled in for the night.

You can see the first part of our trip on this map, although the default view will change with more recent posts, so you might have to page around to find the first, northern leg. The two photos were taken at Honey Lake rest stop on 3Mar2016.

Related Posts (in order of posting):
Death Valley, "Super" Blooms, Turtlebacks, and Detachments
Death Valley Trip, Part 2: More of the Badwater Turtleback Fault
Death Valley Trip, Part 3: Northward, and over Daylight Pass