Wednesday, August 22, 2012

What You Really Need to Know About Tertiary Channels (Conclusion)

(Tertiary "drift" mining tunnel adit at California's Malakoff Diggings.)

We've discussed the effectiveness and the overall environmental impacts of using hydraulicking to mine Tertiary gravels in my previous post. In this post I'll be talking about another historical method for accessing and working Tertiaries, so read on.

"Drift" Mining

The other main method for accessing Tertiary gold-bearing gravels is "drift" placer mining. There's nothing magical about this approach since it closely parallels the type of tunneling common to hard-rock gold mines.

Here's how "drifting" for Tertiary gold was done in the old days:
  •  Miners would identify a likely spot where Tertiary gravels were visible (usually higher up on hillsides in California).
  • Next, they'd dig (using picks and shovels) an adit or tunnel entrance directly below or into the gold-bearing gravels themselves.
  • They'd follow paystreaks laterally or even vertically as those paystreaks "drifted" in various directions.
  • Gold-bearing Tertiary gravels were dug out by hand methods and then processed through rockers, sluices, or long toms. (In larger "drift" operations, wheelbarrows, ore carts, or windlasses were used to expedite the removal of "paying" gravels.)
That's Tertiary "drift" mining in a nutshell.

Imagine...

Both hard rock mining and "drifting" are similar in that both can be accomplished with one or two small-scale miners or alternately, with a concerted effort involving many miners and lots of gear and equipment. One of the main differences between the two approaches (hard rock vs. placer "drifting") however, is that Tertiary "drift" tunnels were rarely shored.

Mining Equipment
Gold Concentrates
Gold Concentrators

Hard rock mining can be scary in and of itself when you're tunneling into a hillside or mountain even when the walls are nearly solid rock and square-set timbering is used to prevent potential collapses. That said, imagine yourself digging into or underneath ancient river channel gravels with absolutely NO SHORING and where the overhanging ceiling and the side walls are nothing but boulders, rock, gravel, clay, dirt, and sand.

Stupid or Ballsy?

You can call the old timers stupid or ballsy but either way this sort of Tertiary tunneling or "drifting" was (and still is) very scary business. Collapses were common occurrences and many "drift" miners were crushed, buried, or suffocated as un-shored Tertiary gravel overhangs or walls collapsed.

I myself have had the dubious pleasure of checking out numerous "drift" placer mines over the years and I can tell you this...they are scarier than hell. I rarely, if ever, enter them completely but simply crawl or stoop into the adit to take a look around.

Barely Large Enough to Squeeze Through

In the Old Placers District (only 14 miles from my home here in Northern New Mexico), there are a number of "drift" locations where the old timers dug into ancient terrace gravels (18-22 million years old) to get at the gold. The adits of these are barely large enough to squeeze through and to do so you must crouch or wiggle through prone...a frightening prospect for someone even with mild claustrophobia like myself.

(Another old Tertiary "drift" mine..this one's filled with water now.)

Inevitably, these "drifts" open up into larger chambers surrounded by gravel and rock and covered with pick marks. These larger "rooms" still do not allow you to stand upright and numerous smaller "drifts" move off in various directions. The latter are so narrow and small you could only work these on your knees or completely prone.

No Way

Can you imagine yourself mining this way? Trying to wield a pick or shovel laying on your back or on your knees with tons of rock and gravel suspended over and around you?! No way, no how.

Sure, there are some placer "drift" mining operations still ongoing today in various parts of the United States. However, these mines are not small-scale endeavors per se and they must follow strict Federal and state safety guidelines in terms of exactly how they're operated.

An Admonition

So you see brothers and sisters, mining Tertiary Channels is not an easy undertaking. In fact, it's nigh on impossible for a single miner or mining duo to pull off and actually get large amounts of gold. That's the reality of the matter, no matter how much BS the dream merchants try to force feed you about striking it rich with "ancient rivers of gold."

One last admonition for you. Please, please, PLEASE stay the hell out of old "drift" mines. I understand your curiosity and your desire to get more gold, but as I 've said before...no amount of gold is worth dying for.

Good luck to one and all.

If you liked this post, you may want to read: "Working Bench Gravels (Part 1)"

(c)  Jim Rocha (J.R.)  2012

Questions? E-mail me at jr872vt90@yahoo.com

10 comments:

  1. Why aren't these types of old mines demolished? I understand some mines can be considered historical, but there are many that never really paid out and pose a hazard. They are neat to explore, but thats what gets you in trouble.

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    1. There are so many of these old mines and shafts scattered throughout the West and Southwest that's a nearly impossible task. However over the past 15 years or so, there's been a concerted effort by state and Federal agencies to seal some of these mines off, gate them, or bury them. J.R.

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  2. Jim, Very interesting stuff here! Any idea why they didn't timber them? Seems like the looser the rock, the more timbers you would use. I would at least..... Gary

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    1. I honestly believe the old timers didn't use shoring most drifts simply for the sake of expediency. It takes time to cut down trees, saw out or hew square sets, and it costs money to boot (time = money). They wanted to get at the gold the quickest way possible and were willing to take the risk. However, there were some Tertiary drifts where the gravels were pretty well cemented into place by clay or caliche (in dry placer locations). Best, J.R.

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  3. JR

    It terrifies us to think of all of the miners that have died while drifting only so much as a coyote hole.

    We're open to drift mining, but it certainly comes with dangers. Paul's got broad shoulders and to swing a pick he'd need lots of room. The running line between us is "Let's Blast." Ah the good ole days of buying dynamite at your local hardware store.

    Have you ever known any hard rock miners who have mined wearing oxygen tanks in case they run into bad air?

    Thank you for the fine info on Tertiary Mining. An expose that couldn't have been done any finer. We only hope we have the priveledge of running gravel with you someday.

    Amber and Paul

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  4. Amber and Paul, thanks for the good words and your comments. One thing you'd never want to do with Tertiary type drift mines is use dynamite. The blast would scatter the gravels and the gold everywhere. That's why the old timers dug systematically by hand or hydraulicked where they could "direct" the flow of gold-bearing gravels. I have not run into any small-scale hard rock miners using oxygen...so no on that one. One last thing...you and Paul stay out of any drift mines you come across, OK? J.R.

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  5. My family has been drift mining for years. Thank you for showing Much concern, SAFETY,SAFETY,SAFETY. can not be stressed enough.To enter any drift without the right gear is CRAZY TALK. am now 40 yrs young and just starting my turn at Mucker,,I will be seeking the ever elusive elephant,,

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    1. Yep, safety is first and foremost. "Seeing the elephant" is probably something most of the readers have never heard of. You and I know what that means though...that saying goes wayyyyyyyy back! J.R.

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  6. I am very thrilled to start working my family Drift. Safety is top priority..as it was first opened in 1856...

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  7. Best of luck to you and your family in working that drift. Let us know how you do. Best, J.R.

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