Things You Find in the Field: Metal Bars, Mine Dump, and Adit

Going up the trail of our old hiking hill in eastern Nevada...

...we'd run right below this old mine dump kind of sprawled across the terrain, with large piñon and juniper trees growing around it and small piñon, sagebrush, and ephedra growing on it. I suspect the trail is partly an old miner's or mule trail put in to access the small mine.

At the base of the dump lie a few pieces of metal.

The metal bars are flat and elongate, with drilled holes at some undefined or irregular spacing. I have no idea what these were used for. At first I thought they had something to do with an old rail-and-cart mining system, but closer examination shows they are too flat to be regular track of any sort.

UPDATE 31Mar2013: The metal bars may be pieces of "strap rail," which would have been attached to wood to create an inexpensive rail system. H/t Guy Starbuck in the comments below; be sure to check out his fine website and blog, Starbuck's Exploring | Exploring historic mine camps and petroglyph sites of the Southwest.

The trail then goes uphill to the side of the dump...

...and peters out into a somewhat slumpy area of soft talus. We usually continue up to the top of the hill from here on a poorly defined trail, but today, let's go examine the top of the dump.

A small opening at the top of the mine dump goes into limestone bedrock.

Let's look a little closer!

Standing on the somewhat caved material at the adit portal, looking inside...

...we see one of those mysterious pieces of metal [see update above] sticking out from limestone debris lying on the sill (what a layman might call the "floor").

Not sure what this writing is all about.

The iron bar points down the adit.

In the back and upper ribs of the adit ("top" and "sides"), a darker, less oxidized limestone can be distinguished from a lower, yellowish orange limestone. This contact would be mappable underground only where it crosses the right rib at waist level, which it might right near the adit portal.

Using the flash of my camera, we can see that the adit continues quite a ways into the hillside.

Now, back on the mine dump, we look south toward Ward Mountain
in the Egan Range.

Looking over the edge, we see the metal bars [strap rail?] at the base of the dump. Shall we go back down?

I don't remember if this was a great boot-skiing dump. I think I went around the side to get back to the bottom.

Three metal bars in the sun.

Closer view: metal bars and ephedra.

Looking back toward the metal bars, we decide to hike back down the hill.

A Mini-Rant about Mine Dumps

"The briefest description of waste rock dumps is from Western Australia—all you need to know in two pages. [May not be original link; also condensed here to one page.] The most comprehensive description of a waste rock dump is in the EduMine course Design and Operation of Large Waste Dumps. In practice no definition is needed; simply see the picture on the front page of this review."

— Jack Caldwell, from Waste Rock Dumps, rev. 28 June 2006

A mine dump, or waste rock dump, by definition consists of waste rock from a mine — whether it be an underground or surface mine — that has been dumped somewhere, usually quite close to the mine, sometimes even inside a surface or underground mine, so as to minimize motorized or track haulage costs.

Old mine dump.

A heap leach pile (or leach pile or heap) is not a mine dump: the rock consists of ore that is (or was at some time) being processed by some form of leaching. A leach pile sits on a leach pad liner, and can't be moved without placing it on another liner (environmental requirements).

Tailings should not be called mine dumps, either: they are the tails that have come out the back end of the ore processing plant; the heads went in the front end. Tailings (or tails) were once ore, not waste, or they wouldn't have gone into the mill for milling and then processing. They are usually found behind tailings dams (although not always). Tailings shouldn't really contain any ore, but sometimes — perhaps if the mill or recovery plant isn't operating properly or if the ore going into it is of an unexpected or unusual character — some amounts of the ore mineral may get through to form ore-bearing lenses behind the tailings dam. Sometimes — usually in the future when (if) the price has gone up, unless your mill is currently letting through too much unprocessed mineral all the time (therefore right now and also in the future) — the entire tailings mass may comprise a low-grade ore deposit. Many tailings deposits have been sampled or drilled as potential ore. Tails near Kalgoorlie have been mined; Eldorado Gold plans reprocessing of tailings at its Olympias, Greece, project.

Mine dump inside old, inactive open pit.

Many mines stockpile various kinds of ore, often ore that is in an intermediate low-grade category below one cutoff grade and above an absolute minimum cutoff grade. For these "low-grade" stockpiles, the plan is to process them through the mill or on a heap leach pad at some later date, either when (if) the price goes up or toward the end of the mine when many up-front mining and processing costs have been paid off. Sometimes these stockpiles become waste (and therefore become part of a larger mine dump or waste pile) simply because they don't get mined: the price doesn't go up, or end-of-mine costs aren't low enough to make them worth re-hauling, or mining is shut down for whatever reason before the low-grade stockpiles are processed. Other types of ore stockpiles include those made of high-grade ore or some particular type of ore that is recalcitrant to your usual processing. These piles may require special processing or blending with other types or grades of ore.

Mine dump in fog at sunrise.

Waste on mine dumps can become ore at a later date if mining and milling technologies improve or if the price of the commodity of interest goes up. Material on leach pads theoretically becomes non-ore as the metals of interest are leached out, but again, the material is subject to future price and technology changes, and leach pads fail to produce sometimes, leaving the original metals intact or partly intact (it could be argued that the leach piles with unfavorable recovery rates were technically not ore in the first place). I suppose that one could argue that the material on already leached pads is now waste rock, and therefore the old leach pile is a mine dump, but as I mentioned before, the pile is probably on a liner, and it therefore has to be handled differently from any other piles of rock around the now inactive mine.

One could also, perhaps, argue that the tails or tailings are now waste and therefore a mine dump, but I cringe at this idea, because there really is a specific name for that material: tails or tailings. Tails can become ore after their creation if mining technologies improve or if the prices of commodities contained within go up. One hopes that a mill isn't putting too much metal out in the tails; that usually implies a poor recovery rate, and poor recovery rates are usually unfavorable to profitable mining. And mining has to be profitable, or the individual mine owner or individual miner (yes, there are a few), the mining company, or the shareholders of a mining company would be better off putting their money into a bank or a mattress instead of investing in the mine.

Old mine dump.

Most of the mine dumps I see out and about are waste piles and dumps near an old working: a shaft, decline, adit, glory hole, or other old and inactive complex. When I'm working at or near an active mine, I can usually recognize the mine dumps because the haul trucks are actively dumping loads of waste. It can, however, be difficult to look at any given mine and know which piles of rock are currently in the waste or ore category.

I do get tired of hearing every single pile of rock near a mine being called a mine dump.

/rant

Things You Fnd in the Field: Holes in the Ground #1

While out wandering around here and there in Nevada, and other places throughout the west, you might run across mine dumps and associated various holes in the ground — adits, shafts, declines, and other irregular openings — put in, usually, by old-style prospectors and small or individual miners.

Small irregular opening with small mine dump.

Larger mine dump: Let's go see what's there!

It's a small shaft with old timber as shoring. The round-headed wire nails suggest that this is a relatively recent shaft: probably post-1910. 

Openings like this are, nowadays, often blocked off with chain-link fencing or other barricades, which is a fine thing for preventing random people from falling or driving in — often those who happen to be wandering around after dark, or who might be driving across the hills without a good idea of where they are (an old mining district), where they are going (cross country where there isn't a road), or what they are doing (possibly out for so-called fun after a couple beers) — but they make it difficult for people like me to figure out what the old-timers were digging on, and why, and can prevent sampling the rock, vein, or structure to determine its geochemistry. Barricades can also prevent me from going into accessible adits for sampling and underground geologic mapping, and can prevent or at least hinder other geologists with the know-how and right equipment from going down shafts for sampling and geologic reconnaissance or mapping.

This particular hole was unbarricaded.

Beyond the timber and the rock overhang, the small shaft appears to end only a few feet below the surface, although my photo doesn't show whether an underground drift takes off from the area hidden by the rock at the opening. Enlarging the photo reveals several narrow, parallel white lines across the photo that make it clear that it was raining that day. Enlargement also suggests that a drift does take off from the far side of the shaft, as does the relatively large size of the associated mine dump (second photo).

You always have to ask this question: What were the old-timers digging on? A few, narrow, high-angle fractures or structures can be seen above the first irregular opening or adit. Iron-staining and possible veining (silica? calcite?) can be seen in the rock at the shaft. Did they mine anything? Hard to say without doing a little more research into the area or more work in the field.

Upper Champion Mine Workings

Now we've turned the corner from the lower workings of the Champion dumortierite mine area and are looking straight up the old, now impassable road that once led all the way to a prosepct at the top of the hill. The dump for the uppermost prospect — with small juniper tree growing on it — is barely visible on the far left end of the uppermost outcrops in the left part of the photo, just beyond and behind the reddish brown, cliffy outcroppings of the middle foreground.

After hiking up the wash a little ways we came to this old ore bin, which is still connected to the upper workings by cables.

Looking inside the ore bin via the chute.

I looked inside the ore bin to see if there was still any ore. What I found, besides a few patches of thin snow, were a few small pieces of purplish blue (or lavender) dumortierite, which I'll show later. These chips, and a few similar ones lying around on the ground below the chute, were a different color than the standard purplish red (or rose) dumortierite I've always seen in the area, and it made me wonder if the bluish color indicated anything significant to the miners, or if it was just a chance find on my part, or if it indicated a possibility that the upper workings were entirely in the purplish blue variety of the mineral.

An adit next to the ore bin. 

A few of the cables going from the upper workings to the ore bin are bolted into the outcrop above the adit.

Closer view of the opening to the adit, its door more than half open.

Looking at the upper workings from the ore bin, the cables strung overhead.

At this point, we decided our hike and prospecting of the area was done for the day, so we didn't make it up to the upper dumps. We saved the area for later.

Instead, we had this view of the upper workings when we stopped at the Humboldt Queen (mentioned here) before driving on to Rochester Canyon.

Google Earth view of the entire Champion Mine area.

Related Posts:
Friday Photo: Dumortierite
The Road to the Champion Mine
Rock Walls at the Champion Mine Lower Workings
Dumortierite at the Champion Mine, Nevada

Rock Walls at the Champion Mine Lower Workings

We had just started up the hill to the lower workings of the Champion Mine in the Rochester mining district, Nevada.

Three rock walls.

The lower workings are a mess of mine dumps, scattered junk, and locally heavy brush amidst three well-defined rock walls below a cliff of Rochester Rhyolite.

Corner of the lower of the three walls.

The rock walls are built of dumortierite-sericite schist from outcrops of the Triassic Rochester Rhyolite, part of the larger Koipato Group of Triassic volcanic and volcaniclastic rocks. I'm guessing that the walls were possibly used to provide flat places for mining activities near the workings on the very steep slopes, rather than as foundations for shelters, buildings, or mills: we found no signs of such structures.

View from the lower wall, looking WSW down Rolands Canyon.

The second or middle wall as seen from below.

The third or upper wall, medium brown in the upper left of the photo.

Standing on the second wall, the third, or upper wall becomes apparent, high on the slope, nearly blending into the cliffy outcrops of Rochester Rhyolite. The funny, corrugated, white to beige or orange-brown outcrop at the far end of the flat platform contains dumortierite in fibrous masses, which we'll see in a later post.

View from the upper or third wall, with the first and second walls below.
My jeep is no longer visible.

Now we've gone back to the bottom of the hill, and are looking straight upward at all three walls.

From just above the jeep parking location, only the first and second walls can be seen.

But, before we had made it all the way back to the parking area to drive away toward continued adventures, MOH and I had turned and walked up the very old, impassable road to briefly investigate the upper workings.

To be continued...

The Road to the Champion Mine

We came in from the east or north, depending on how you view the direction of I-80 as it traverses the entire north-south length of the west flank of the Humboldt Range from Florida Canyon to Limerick Canyon northeast of Lovelock.

The Oreana–Rochester exit from the north on I-80.

We took Exit 119, turning off onto the Oreana–Rochester road, a paved road that goes up Limerick Canyon to Spring Valley Pass and the turnoff to the Coeur Rochester Mine.

The I-80 underpass near Oreana.

Go straight ahead, under the underpass, do not turn left back onto the freeway, unless you'd prefer to go to Rye Patch or points north.

The junction of the Limerick Canyon and Rochester Canyon roads.

To get to the Champion Mine, stay left at this junction, on the paved Limerick Canyon road. Don't take the dirt road to the right, which goes to Rochester Canyon. After the junction, you will take the first dirt road to the left, a fairly decent alluvial fan road. The right turn onto the road to the Champion Mine is marked below in my newly added location section, above the blog tags or labels (if clicked, the location will open in Google Maps).

No trespassing sign.

The dirt road up Rolands Canyon to the Champion Mine is a narrow, high clearance road with lousy turnouts in case you happen to meet someone coming up or down. You'll pass a small No Trespassing sign, which is there because of the spring and an old, not presently used (AFAIK) trailer at the cottonwood tree.

Rolands Canyon should be Rowlands Canyon, named after R. H. Rowland, who had some claims in the area of the Humboldt Queen Mine and Humboldt Queen Canyon back in the 1920's (NBMG Bull. 8, p. 10). Humboldt Queen Canyon is not named on topo maps of the area, but lies between Rolands Canyon and Limerick Canyon (MSRMaps location; USGS TNM Viewer topo).

We took a little side road to the Humboldt Queen, which gave us this view of the spring...

...and this view of the Champion Mine, high on the hill above Rolands Canyon.

A long time ago, on one of my first mineral collecting and mine visiting trips in Nevada, I went to a dumortierite prospect or old mine high on the western range front of the Humboldt Range up some long and narrow — and I thought rough — 4WD road. A long-time grad student with plenty of Nevada and 4WD experience was driving; he exhorted me to always drive with my thumbs on the outside of the steering wheel when traversing backcountry dirt roads.

Most 4WD trucks (all?) lacked power steering back then, and if you hit a rut or rock, the steering wheel could twist radically, and thumbs could get sprained, or worse. (Ford introduced power steering in trucks in 1959 (or 1954?); it became an option in their 4WD trucks in 1979 (or standard by 1977?).)

I still drive with my thumbs outside the wheel on dirt roads.

View of the main Champion Mine workings from a very old road.

The road to the Champion Mine has few pullouts in its steepest and curviest spots, and someone coming downhill when we were going up had to (begrudgingly, it looked like), back up and pull over into a large bush-tree to let us continue going uphill. (A Rule of the West: Drivers going uphill have the right of way on dirt roads, although it seems like very few people know that these days.)

When MOH and I walked up the part of the road that is now completely impassable, I thought the old road, now washed out and heavily overgrown, looked like it hadn't been used for at least 50 years. (But it's been quite a while since I actively knew the ages of old roads and had a lot of practice with road-age estimation.) And when I couldn't identify a road going right to the main dumps, I was became convinced that this wasn't the same dumortierite mine I went to back in '76. (Air photos do indicate a road going to the upper dump, coming in from the direction I remember, so it *is* possibly the same mine.)

Current end of the road, as seen from some lower workings.

And so, we had reached the end of the road and turned around and parked leaving room for someone else to turn around if they came up while we were hiking and prospecting. And we had hiked up the old, overgrown road and climbed the hill to look at the lower workings.

To be continued...

Back to Midas

At long last, we're back on the Tuscarora Loop, with the turnoff to the small town of Midas just up ahead. On our loop trip, taken way back in early June, MOH and I passed Midas by, in favor of making it all the way to Tuscarora. At the time, I had been to neither place, but Tuscarora seemed more out-of-the-way, and therefore more exotic, so down the road we went.

We came back in mid-July, and instead of following the main road, old S.R. 18, to the right, we took the side road up the canyon to the left.

Signs at the turnoff to the Midas road.

Sign at the entrance to the town of Midas, and green trees.

Acme Beer sign, reportedly dating to about 1936.

I was on the lookout for a bar that had been open in 1979 or 1980, a bar I knew as Kirby's Midas Bar, a name given to me by a friend of mine, a young woman who was working as a geologist while staying in Midas in a company trailer. Seeing the old sign for Andy's Midas Bar made me somewhat hopeful about finding either Kirby's or Andy's bar, although Acme Beer dates back primarily to the early 1950s and before. Acme Beer did have a short revival in 1975 to 1979; could it have possibly been being sold in Midas while my friend was in town?

While in Midas, my friend could make or receive phone calls on one of the two phones in town, which had the phone numbers of Midas #1 and Midas #2. Phone numbers like these were fairly common in the 1970s and early to mid- or late 1980s in the small, outlying towns of Nevada. These numbers confused operators outside the state to no end. To place a call into Midas or Getchell, for example, you would dial 0 for an operator and then ask for Midas #1 or Getchell #2 as needed. If dialing in from out of state when trying to reach one of these types of numbers, one learned quickly to ask the out-of-state operator for a Nevada operator, because many outside operators didn't believe that phone numbers like that could even exist.

While I was looking for, and not finding, the bar I'd heard of long ago, MOH and I were hoping that the one known-to-be-operating establishment in Midas, the Midas Saloon and Dinner House, would be open, but it wasn't. This became a concern during a later, uphill, in-the-rain adventure of ours.

Mine dump, ore cart, and portal (?) a little ways up Midas Creek.

Old cabin, garage, or storage shed.

Road to somewhere.

After a quick pass through town, we headed up the hill to the west on this relatively innocent-looking side road. The partly cloudy weather became more and more threatening as storms to the south moved in, creating an unexpectedly muddy situation.