Tuesday, May 18, 2010

Bedrock Gold Recovery Tips: Watch Those Drop Offs

(Kane Fisher sampling a bedrock drop off in New Mexico's San Pedro Mountains.)



Drop Offs Can be Good Producers

Bedrock drop offs are another very important location to check thoroughly when you are out in the field, especially if your primary mining focus is crevicing or sniping. Like many other placer gold deposition points, drop offs can be very good gold producers if you know what to look for.

OK, right off the get go I think I know your first question. "What the hell's a drop off?" Here's my answer to you:

Drop offs are spots along a given stream course (wet or dry) where auriferous material passes over and then pretty much straight down in a stair-step fashion. For example, most waterfalls are extreme examples of drop offs and by the same token, are not good gold producers for a number of reasons including the height of the drop and excessive turbulence below it.

All Shapes and Sizes

A much better example of a decent-looking drop off can be seen in the photo at the beginning of this post. Here Kane Fisher (my erstwhile mining "pard") samples a final bedrock drop off in a series of small drop offs along this stretch of wash.

Drop offs come in all shapes and sizes and some are formed from the local bedrock itself or from build ups of trapped rock and gravel above. In terms of size I think the smaller (4"-12" in height) drop offs are the best producers, especially in dry washes and in smaller wet placers. My statement here is based on many, many years of mining experience and direct observation out in the field.

The Best Drop Offs are "Just Right"

I'm not entirely sure why this is so, but I suspect it has to do with the force that the height of the drop creates as material slides over and down it. Too slight a drop and the material tends to wash out downstream and in too high a drop much the same condition prevails.

The best drop offs tend to be those that are like Little Bear's porridge in the nursery tale, "Goldilocks and the Three Bears." In other words, they are "just right."

Wave Your Hands in the Air and Shout!

Once you've found a drop off or series of drops offs that are "just right" in terms of height, take a close look at what lies beneath the drop off or series of drops. Is only a slight bit of gravel or rock resting atop bedrock that is partially visible and smooth looking? If so, pass this drop off by because the gold has headed for a better drop off and trap.

Gold Prospecting Books

However, if you spy a small drop off that has gravel, heavy pieces of black sand, and perhaps some clay and roots all packed tightly beneath it, then brothers and sisters lean back, wave your hands in the air, and shout "Hallelujah!!" You done hit the good stuff!

What This Means in Real Terms

What this means in real terms is that beneath that drop off is probably a depression, crack, or crevice that is acting as a trap for anything the drop delivers below. For a bedrock sniper this is another form of very good gold ground and you want to clean that material out thoroughly from beneath that drop off.

You don't need fancy gear to do this either, and that's one of the nice things about working drop offs like this. Just a good gold pan (Garrett's "Gravity Trap" or "Super Sluice"), a 5-gallon bucket, a few crevicing tools, and perhaps a crevice sucker or suction bulb. Oh, and don't forget....something to put those coarse flakes, chunkers, and small nuggets in.

Good luck out there my friends.

If you liked this post, you may want to read: "Bedrock Dreams" Donation Drive Raffle: Win 1 of 3 Great Prizes"


http://goldbedrockgold.blogspot.com/2010/05/bedrcok-dreams-donation-drive-raffle.html

(c) J.R. 2010

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

2 comments:

  1. You are dead on with the just right aspect of looking for drop offs. On a particular stretch of river that I have worked several times, there is this one drop off that consistently produces gold each year. Nearby are other drop offs that do not produce as well. The others are just slightly too shallow of a drop off.

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  2. Thanks much for your comment James and the validation it brings. I too have seen decent drop offs consistently produce time and time again...unfortunately, they are often overlooked by many would-be placer miners. J.R>

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