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Geology of Lode Gold Districts in the Klamath Mountains, California and Oregon
By PRESTON E. HOTZ
GEOLOGICAL SURVEY BULLETIN 1290
 
page 29:
 
POCKET DEPOSITS

An uncertain but probably considerable amount of gold produced from lodes in the Klamath Mountains was taken from small localized concentrations near the surface which are commonly referred to as pocket deposits. Southwestern Oregon, especially, is considered by prospectors and miners to be pocket country. The genesis of these gold pockets is poorly understood.
 
Gold pockets are small, shallow, relatively high grade deposits of free gold with little gangue. They apparently have little or no lateral or vertical continuity, because little effort was made to explore possible continuations of a pocket once the rich, easily attained gold had been extracted.
 
In the southeastern Klamath Mountains Hershey (1910) and Ferguson (1914, p. 40-43) described pocket deposits in the Minersville and Whiskeytown districts that occurred at the contact between slate of the Bragdon Formation and the Copley Greenstone, or at an interface between slate and a dike of diorite porphyry. Veinlets of manganiferous quartz and calcite accompany the gold, which is described as occurring in thin sheets in some places. At three localities the Eldorado, Mad Mule, and Five Pines mines the pockets are sufficiently large and close together to have warranted rather extensive work along the contact; all the workings are within a few hundred feet of the surface. Most commonly, however, pocket deposits have been mined for only a few feet below the surface and abandoned after the obvious gold had been exhausted; most of the pockets in southwest Oregon were seldom mined to depths of more than 25 feet (Diller, 1914). The yield from individual pockets in the Minersville and Whiskeytown districts was from $2,500 to as much as $45,000 (Ferguson, 1914, p. 56, 74). The most famous pocket mine in southwest Oregon was the Gold Hill pocket, which yielded approximately $700,000 worth of gold within a depth of 15 feet (Diller, 1914, p. 45-56). Many other pockets have been mined in the Klamath Mountains from which gold worth a few hundred to several thousands of dollars was extracted before pockets were exhausted and forgotten.
 
Hershey (1910) concluded that the pocket gold was deposited by gold-bearing meteoric water. He postulated that the gold was dissolved from weathered auriferous pyrite and precipitated by reaction of the solution with carbon in slate of the Bragdon Formation. Ferguson (1914, p. 41-43; 1915) also subscribed to a theory of supergene origin with precipitation being caused by carbon in the black slates. He suggested, however, that acid waters dissolved gold from low grade manganiferous quartz veins in metavolcanic rocks through the agency of manganese dioxide. After traveling in solution a short distance, the gold was deposited in irregularities along slate-metavolcanic rock contacts where small calcite lenses neutralized the solutions.

Studies by Krauskopf (1951) and Cloke and Kelly (1964) support Hershey's and Ferguson's hypotheses. These studies indicate that acid meteoric waters containing Cl~ and Mn02 can dissolve and transport gold. In the presence of H+ the Mn02 oxidizes the gold, which then combines with Cl~ according to the reaction:

2Au + 12H- + 3Mn02 + 8C1~ = 3Mn++ + 2AuCl4 - + 6H2O (Krauskopf, 1951, p. 862).
 
Supergene processes may have been responsible for the formation of some of the pocket deposits, but it seems unlikely that the exceedingly rich Gold Hill and Steamboat pockets in Oregon were formed this way. Under certain conditions, where gold precipitation takes place in response to hydrothermal alteration of country rock by veinforming solutions, it is expectable that rich zones or pockets would occur in conjunction with lean or barren zones (Helgeson and Garrels, 1968). It is also unlikely that gold would be transported a very great distance before neutralization of the solutions would cause precipitation; hence, supergene deposits probably are not far from the original hypogene deposits. The presence of carbonaceous sedimentary rocks may not be necessary to the formation of pocket deposits, because in southwest Oregon gold pockets also occur in areas where there are no carbonaceous rocks (Wells and others, 1949, p. 21). Probably many pocket deposits are irregular and discontinuous shoots along hypogene veins and veinlets which have been enriched by supergene processes.

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Here is a picture of the actual Gold Hill Pocket I took in 2012.

And a picture of a 4 oz nugget found on the other side of the Gold Hill pocket in the Rogue River dredging in 2012. Yes, that is my hand holding the big nugget!

The Rogue river is on the backside of the Gold Hill pocket in the pic and it was fed by many many small pockets and a large pocket complex that ran from inside the river all the way to the top of the next hill over from the Gold Hill pocket and stops at the bottom of a house's basement on top of the hill with an explosion of red iron oxide dirt that the pocket complex is contained in (contact zone).

On both sides of the pocket complex are two different types of dirt, bushes and trees. Tale tale signs of a large contact zone. The less rich side of the pocket complex can be identified just by looking at the dirt, good farming type dirt. (dark brown color). The richer side (gold) of the complex the dirt is high in iron, quartz and drives a VLF crazy and is red and more deep orange color. Even the vegitation is different on the rich side.

This is where I find gold in every piece of quartz I pick up (after crushing). Very thick quartz veins that ran across the river here contained large quantities of gold. This is the epicenter of the beginning of the gold in that area. Go 2 miles up river - no gold...

Thanks for the info Steve. I really like pocket gold hunting with a metal detector. I know of 5 rich strikes within 40 miles of this Gold Hill pocket in 2014. I mean rich...sworn to secrecy though. Its still out there folks! GPZ 7000 anyone?? Oh yea...

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I have a little booklet on the subject, How to Hunt for Pocket Gold, by Verne H. Ballantyne,only 23 pages but a good read,stories of old time gold pocket hunters,how tos,tips  

Nice nugget Bearcat, guess it can't hurt to try map dowsing the Gold Hill area? How does one tell the rich gold red dirt from barren red dirt or is it just hit or miss and luck? Got any photos of your rich quartz rocks? How do you crush them?

 

-Tom

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Hi Tom, I just used a large mortar and pestle for crushing with classification around minus 30 mesh during the crushing. The contact zones and the dirt color just pop out at you that something is different. Plus the amout of quartz is definately a sign to investigate. I dont think I have any pics of the quartz, but I look to see if I do...

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I'd like to see some contact zone photos too, near and far, so I know what to look for in the field?

Thanks.

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Tom bohmker up in oregon wrote a couple books about pocket gold.  One was "the elusive pocket gold of s w. oregon and "finding pocket gold in California's klamath mountains.  I believe those titles are right.  I also seen on a canadian gold forum ( cant remember the name) so good post about the geology of them. And also the Australian forums have some good post about them. although I think they call them reefs. alot of prospectors find gold that is from a pocket and have no idea it did. Whether it is on a hillside or in a stream. most of the gold that I collect is from pocket deposits. they are a very interesting subject good luck

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On 3/6/2015 at 7:14 AM, Bearkat said:

 

I use the SDC 2300 to scan quartz that has been pulled out of mines...as well as the ATX. Hard to beat the gold bug 2 for this doing though, prob the best to use for this...

The Falcon MD 20 isn't too shabby either for checking discarded quartz & quartz float material.

Good thread. :)

Good luck out there

JW :)

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