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

We're officially on the Titus Canyon leg of our larger Death Valley trip—a round trip odyssey that will take us to and near a number of places. This section of our journey began with the last post, which was centered around Beatty. I’ll be complementing my February photographs with photos from a similar journey MOH and I took back in the late spring of 2009. So, let's get on with it! We'll begin by leaving Beatty.

There are two ways to get to the Titus Canyon road from Beatty. I usually forget that fact because it's generally been years between journeys into the canyon. Consequently, I seem to end up on this route one time, and that route the next time, alternating routes without really thinking about it. Then I wonder why the road, the signs, and the overall lay of the land don't look the same as the last time I passed through the area.

Beatty's main intersection: a 4-way stop.

We went one way in 2009, turning left at Beatty’s main intersection, which kept us on U.S. 95 as we drove east and then south through and out of town. We passed the dirt turnoff to Fluorspar Canyon (might there be some fluorite up there?) and passed into the Amargosa Narrows. Not far beyond the Narrows, we turned right onto the unsigned paved road to the Beatty Airport, which goes by an obscure ghost town, Gold Center. Airport Road turns to dirt beyond the airport.

The Amargosa Narrows: Precambrian Z rocks crop out on the right, left, and straight ahead.

We went the other way this past February, going straight on Nevada S.R. 374, the Daylight Pass road, at the same intersection. This paved road winds through a bit of the Bullfrog Hills, going by Velvet Peak and Paradise Mountain. It then meets up with Airport Road near the Bullfrog pit of the currently inactive Bullfrog open pit gold mine.

The Bullfrog pit, as seen from the dirt portion of Airport Road, looking across a sea of blooming creosote (from the early May trip, 2009).

The Bullfrog gold mine—AKA the Barrick Bullfrog gold mine—was in operation from 1988 or '89 through 1998, when it produced about 2.4 million ounces of gold from two main open pits, the Bullfrog pit and the Montgomery-Shoshone pit, and from at least one related underground project, the North Extension. Discovery of these ore deposits began in 1982 with St. Joe Minerals Corporation (overall history is described in some detail here, here, and here). The exploration property then passed through several companies in quick succession through a series of acquisitions or buyouts, going from St. Joe to Bond Gold Corporation, then to Lac Minerals Ltd (or LAC Minerals Ltd, depending on the year—this company went back and forth with its name several times in a few years), and then to Barrick Gold Corporation.

The deposit is hosted in Tertiary volcanic rocks, mostly ash-flow tuffs that are cited by Castor et al (1989) as being correlative with the Miocene Timber Mountain Tuff, which has age dates ranging from about 10 to about 15 Ma (Geolex). In fact, the host formation was mapped by Maldonado et al (1990) as the Rainier Mesa Member of the Timber Mountain Tuff.

I had a tour of the Bullfrog pit back in the late 1980s or in 1990, while I was working for Former Mining Company. Bond Gold was probably the operator when I was there, and the mine was just called the Bullfrog mine. We learned then that much of the overall low-grade ore is concentrated in veins, breccias, and stockworks, and we thought at the time the deposit would be fairly difficult to make money at. It later surprised me that a large company like Barrick got involved in the mining. (I have no idea how the economics really played out; so much can depend on the up front expenditures a company has made and the price of gold during production.)

The deposit formed near the end of an extreme extensional event that took place in the area between 11.4 and 7.6 Ma (Castor and Weiss, 1992; Weiss et al, 1995; Castor et al, 1999). Although ore is partly hosted in and controlled by structures in the upper plate of the Bullfrog Hills detachment fault, it's not generally considered to be a detachment-related type of ore deposit (although knowledge of detachment faulting and related structural models would be indespensible for making discoveries in the Bullfrog mining district).

A little farther down the Daylight Pass Road, about six miles from the center of Beatty, the Titus Canyon dirt road heads WSW toward the Grapevine Mountains.

Turnoff to the Titus Canyon road.

The Titus Canyon road is a dirt road of variable character, narrow and washboardy in many parts, and entirely one way east to west. It isn't possible to turn around once you get going, and from asphalt to about "Tan Mountain," [name from Panoramio photo no longer available] there are few pullouts. It's possible that one could exit the road in two or more places within this first section, but it's not clear to me that any of these possible exits are really roads.

High clearance 4x4 vehicles are recommended!

Although 4WD is not usually necessary along most sections of the road, high clearance is a must, and 4WD can become necessary at any time (especially during bad weather). I think the road is blocked from the east when bad T-storms or flash flooding are expected, but I'd always want to check the weather to avoid getting stranded during a bad washout, like the kind the Death Valley area experienced in October, 2015.

This is what the October flooding looked like, during and after:

Don't get caught up in one of these!

Somewhere between the Titus Canyon warning sign and the Death Valley sign, you can look off to the north and see some classic Nevada ash-flow tuff formations, in this case tilted moderately along two detachment faults. The visible roads and workings are in the area of the Original Bullfrog mine, a little less than four miles west, as the crow flies, from the Bullfrog open pit.

Tilted volcanic rocks on Bullfrog Mountain (the highest point in the photo), with the Original Bullfrog mine not far left of center.

Wildflowers and creosote are in bloom in this May, 2009 photo. More precise photo and location information can be had by perusing the map near the end of this post.

I got to fooling around, saving this Google Earth image of Bullfrog Mountain from a similar angle as my photo above.

Google Earth image of Bullfrog Mountain.

Then I fiddled a little more and shortly had a geologic map overlay of Bullfrog Mountain. The two USGS maps used here are the Geologic map of the northeast quarter of the Bullfrog 15-minute quadrangle (Maldonado et al, 1990) and the Geologic map of the northwest quarter of the Bullfrog 15-minute quadrangle (Maldonado, 1990).

The same Google Earth image with two kmz file overlays.

What fun! Okay, this was so much fun, I went ahead and made the image match my photo more precisely, and then added a few geologic labels.

The photo, again, for comparison with the image below.

Geologic overlay of Google Earth (G.E.) image, labeled.

This is a good part of the Bullfrog Hills in which to see the results of the extreme extension that occurred in the area during the Miocene, although I'm not sure if its possible to actually place a finger on the main (or secondary) detachment surface. For the most part, the detachment faults are shown on the maps as dashed beneath Quaternary cover. In only three areas is either detachment fault mapped in the hills where we might be able to go look at the fault planes, and in only two places are dip measurement shown, and both sites are in the low hills to the east of the photo and images.

As for the rest of the local geology, the mylonitized lower plate Precambrian rocks are easily reconnoitered in the light colored hill on the far left of my photo (lower left of the G.E. geologic image), and the tilted volcanic section is easily walked in the hills above the Original Bullfrog mine. The main volcanic formations, oldest to youngest (west to east, left to right), are as follows: Ts3, mostly sandstone, shale, and conglomerate; Tql, quartz latite lava flows; Tlr, the Lithic Ridge Tuff; Tbt2, bedded tuff; Tcb, the Bullfrog Member of the Crater Flat Tuff; Tbt3, bedded tuff; Tpc, the Tiva Canyon Member of the Paintbrush Tuff; Tbt4, bedded tuff; and Tmr, the Rainier Mesa Member of the Timber Mountain Tuff. The Op on these maps is the Ordovician Pogonip Group, here consisting of limestone only 60m thick. The Zm consists of Late Proterozoic metamorphic rocks that have mid- to late Miocene cooling ages related to the regional extension.

Bullfrog ore.

The lower trenches at the Original Bullfrog mine used to be a great place to stop when driving through the area. (The location dot in the last image shows the site of the original mine, not the lower trenches; the lower trenches are more easily seen in the last photo as the small color anomaly below the location of that dot.) The easily unearthed quartz-amethyst veins contain v.g. and other neat minerals (see this post and next week's post). Much of the mineralized material was mined out in the 1980s (or earlier?), and a bunch of it was placed on a nearby heap leach pad. I doubt that leaching was an efficient way of recovering gold and silver from this ore, and we used to bemoan the placing of all this great specimen material out to leach. Not long after my first introduction to the area, which was probably in about 1986 or a little later, someone—no, I really can't won't say who—came and scraped the leach pad, removing all the rock in order to recover and melt the gold and electrum down for a wedding ring (at least that's the story I've heard). I visited the area most recently on the last day of the last millennium (depending on when we say the millenium started). I camped on one of the drill roads after wandering around the roads, trenches, and prospects. I didn't find much. If you ever happen to stop by the area, remember that you're probably on patented (private) ground, at least up near the original mine site, although I don't remember seeing any signs.

The Death Valley National Park boundary on the Titus Canyon is marked by signs, a fence, and a cattle guard.

Here's where we'll stop our journey today, right at the eastern boundary of Death Valley National Park (as an oldtimer, I keep wanting to call it a National Monument).

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

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

Death Valley Trip, Getting There: Black Rock to Lida Junction to Beatty

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

Death Valley Trip, Part 3: Northward, and over Daylight Pass

We're still on the road in Death Valley and have stopped between the turnoff to Natural Bridge and the southern entrance to the one-way Artist's Drive to look northeastward toward the Black Mountains.

Geology is everywhere in Death Valley, whether you look up or down, north or south, east or west. Consequently, although MOH and I were there mostly to see this year's "superbloom," the lion's share of the photos we took show a lot of geology, which I could only arm-wave or guess at when driving through. I've done a bit of research in these several days after getting back, read a few things, and looked at a map or two (see references below), thereby reacquainting myself with the general geology of the area. For this post, I'll mostly be using the geology, including formation abbreviations, from this USGS map and accompanying report.

So, what do we see in the first photo, besides a nice carpet of desert gold on the alluvial fan in the foreground? Well, I see a seemingly messy pile of white, buff, gray, and brown slope-forming rocks in front of reddish and brownish cliff-forming rocks, with the highest parts of the mountain topped by white, gray, pink, and brown layers. I suspected that the lower, rounded hills would correlated with the ashy layers occurring along Artist's Drive (the Miocene Artist Drive Formation), but I was wrong. Workman et al. (2002) mapped the lowers hills as Tvg: These are part of the 5.4 to 6.0 Ma Greenwater Volcanics, which consist of rhyodacite flows and ash-fall tuffs. The dark rocks in the cliffs behind the low hills are 8 to 12 Ma rhyolitic to andesitic flows and tuffs, mapped as Tar, with a couple thin, lighter-colored layers of what they map as Ts4: undifferentiated Pliocene to Miocene sedimentary rocks. Ts4 seemingly includes the Miocene Artist Drive Formation, although they don't specifically mention it in their report. The mountains are capped by the same ashy volcanic rocks that are in the low hills, possibly offset by faulting: The map shows two presumably normal (though not labeled) faults between the Tvg of the low hills and the Tvg capping the cliffy part of the Black Mountains.

Now, at the same location as in the first photo, we're looking north toward Artist's Drive, which is in the low area just left of center.

The low, dark hills in this second photo are composed of the Greenwater Volcanics (Tvg). Everything else is a jumble (or dog's breakfast) of lighter-colored  rocks mapped as Ts4 and brownish gray rocks mapped as Tb—i.e., a pile of faulted and interbedded (?) Artist Drive Formation (mapped as Ts4) and basalt (Tb).

Once again, MOH and I drove quickly through the Furnace Creek area without stopping, to continue northward. We finally came to the turnoff to the Daylight Pass cutoff at Beatty Junction. The next photo is from just after the turn onto the cutoff road.

Looking NE, with a  low part of the Grapevine Mountains in the background.

The low, dark brown hill beyond the desert-gold-carpeted alluvial fan is underlain by Ts4 (Artist Drive Formation?). The intricately dissected, crinkly hills just beyond, with numerous alluvial fans covered with desert gold, are underlain by what is mapped as QTa, or "oldest alluvium," thought to be middle Pleistocene to late Tertiary (Workman, et al., 2002a). The jagged-looking hills beyond, a low part of the Grapevine Mountains, are underlain by various Cambrian sedimentary formations.

As we drove a little farther up the road, the light was getting low.

Here we're looking southward toward the the 11,048-foot high (3367 m) Telescope Peak, barely visible behind closer ridges. Wildrose Peak is the rounded peak on the right; the peaks to the left include several unnamed ones along and above Colville Ridge.

Now we're standing on what looks like average desert pavement, with a little desert gold growing in a small rill.

It turns out that this graveled hill is underlain by what has been mapped as Qlc, "old lacustrine deposits" (Workman, et al., 2002), which are late to middle Pleistocene in age. In fact, this is one of two linear ridges, as seen below in a Google Earth image. These might be old spits or bars, and they are marked by lines that might be shorelines.

Google Earth image showing two linear ridges (Google Maps link). The pin marks the approximate location of 3DV006-009 (the previous two photos and the next two).  

Bright desert gold (Geraea canescens) on brown, wrinkled hills of QTa (oldest alluvium). The dark hill on the right is part of the Death Valley Buttes, which is underlain by CZw, the Cambrian-Precambrian Wood Canyon Formation.

Desert gold along one of the rills running southward off the linear ridge.

The dark brownish, low hills beyond the lacustrine ridges and alluvial slopes are composed of more Ts4 (I'm not qualified to say it's Artist Drive Formation), and the high country beyond is part of the Funeral Mountains, largely underlain by late Precambrian and Cambrian rocks. The tilted rocks in a hill or mountain just right of center is shown as Cnbc on our map: the Cambrian Nopah, Bonanza King, and Carrarra Formations. In general, it's the lower far hills and the mountains to the left that are underlain by Precambrian rocks.

While we were stopped at the roadcut through the liner ridge, a photographer told us we should look out for a particular desert five-spot that he had put a rock ring around, which would be up ahead near Milepost 8. Apparently the five-spot is considered one of the more beautiful of the myriad desert flowers, and it is sometimes described as rare.

We drove north up the cutoff road, diligently looking for Milepost 8. Just when we had given up on seeing any mileposts (where were they? hidden? were we distracted by wildflowers and geology??), we found MP 6. From there we counted our way slowly, and pulled over right next to MP 8. Where was the rock ring?

It wasn't far uphill from MP 8, right alongside the road.

Desert five-spot (Eremalche rotundifolium) inside a circle of rocks.

A closeup of the same plant.

The location of this plant (and all the photos) can be seen in the embedded MyMaps map, below.

The sun was low, we were hungry, so onward and upward we rolled, turning back to take one last photo or two looking south toward the mostly shadowed Death Valley.

Looking south toward the Death Valley playa.

Once again, the low, dark brown hills are underlain by Ts4; the wrinkly hill of oldest alluvium that we saw earlier can be seen to the right of the dark hills. Telescope Peak is the faintest, snow-covered peak in the distant Panamint Range, on the right; the Badwater and Mormon Point Turtlebacks can be seen in silhouette on the left, far down the basin toward and beyond Badwater.

=========

This post ends the first day of our Death Valley wildflower trip, although I haven't yet posted about the Titus Canyon leg of this journey. Part 1 was here, Part 2 here. This is Part 3. There has been a geologic component to all of these posts, so far. How could there not be?

I will probably now move all the way back to the beginning of our trip, which began two days earlier and miles to the north under cloudy skies. I'll work my way south to Titus Canyon, which may take more than one post. (Titus Canyon is huge, for geology!)

Selected References:
Greene, R.C., and Fleck, R.J., 1997, Geology of the northern Black Mountains, Death Valley, California: U.S. Geological Survey Open-File Report 97-79, 110p.

Hunt, C.B., and Mabey, D.R., 1966, Stratigraphy and structure, Death Valley, California [pdf]: U.S. Geological Survey Professional Paper 494-A, , 162 p.

Lengner, K.E., 2009, A trip through Death Valley's geologic past: Deep Enough Press, 66 p.

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

Miller, M.G., and Pavlis, T.L, 2005, The Black Mountains turtlebacks: Rosetta stones of Death Valley Tectonics [pdf]: Earth Science Reviews, v.73, p. 115-138.

Troxel, B.W., and Wright, L.A., eds., 1976, Geologic features, Death Valley, California [pdf]: California Division of Mines and Geology Special Report 106 [several articles].

Troxel, B.W., and Wright, L.A., 1987, Tertiary extensional features, Death Valley region, eastern California [pdf]: in Hill, M.L., ed., DNAG Centennial Field Guide v. 1, Cordilleran Section: Geological Society of America, Boulder, p. 121-132.

Workman, J.B., Menges, C.M., Page, W.R., Taylor, E.M., Ekren, E. B., Rowley, P.D., Dixon, G.L., Thompson, RRA., and Wright, L.A., 2002, Geologic map of the Death Valley ground-water model area, Nevada and California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2381-A, Pamphlet text, Sheet 1, Sheet 2.

Wright, L.A., Otton, J.K., Troxel, B.W., 1974. Turtleback surfaces of Death Valley viewed as phenomena of extensional tectonics [abs.]: Geology v. 2, p. 53-54.

Bonus Photos:

The crinkly, wrinkled hills in a wider view.

A zoomed view of desert gold and the Panamint Range, with Telescope Peak a little more apparent than in the earlier, wide-angle view.

A wide-angle view from the linear ridge.

All photos in this post were taken on Leap Day, 29Feb2016.