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Author Topic: Old Time Prospecting Methods  (Read 129234 times)

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Offline damionwaltz

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Re: Old Time Prospecting Methods
« Reply #20 on: August 24, 2013, 11:23:52 PM »
It is very exciting!  It is placer only, I have been looking into the history of the area and no mention of gold which can be good or bad.  I have discovered where the gold trail continues.  Its on the other side of the river along a dried up area that looks like it use to be where the river ran.  I panned under one rock and got an average of 4 flakes per pan which is the best I have seen so far (and it is getting coarser).  Crazy cause where i was digging is an area where people camp alot and on a trail.  Would have never thought to dig there if the gold trail didn't guide me there.  The worst part is I found this and ran out of time, now I have to wait till next year to continue my hunt.  Its a treasure hunt for sure and will be on my mind till I get there again.  In the mean time I will be studying the maps and looking for old maps of the river to see if my theory of where the river use to run is correct.  Its killing me just writing this not being able to follow up and see it to the end, hopefully the big pocket ;D

Offline tamarackman

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Re: Old Time Prospecting Methods
« Reply #21 on: August 26, 2013, 08:52:05 AM »
well the summer isn't over yet, if you want it bad enough anything is possible.

Offline EMF

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Re: Old Time Prospecting Methods
« Reply #22 on: November 06, 2013, 12:50:26 PM »
This may have been posted before in another spot, but I can't locate it with the search function. Easier to find here.

                                           
                                                 Searching for Hidden Veins
M & S Press
December 27, 1902

   The difficulties which beset the pathway of the prospector are many. The pioneer of the desert region has many hardships and troubles, but his work,  that of searching for veins, is comparatively easy, for each vein usually outcrops strongly, and may be readily traced along the surface. Very different, however, is the work of the prospector in the north country, where the mountain sides are densely covered with timber, standing and fallen, and thick accumulations of debris, overgrown with moss and  underbrush, hide every vein, often beneath several feet below the surface. The alluvials of the neighboring canyons and gulches may give abundant evidence that veins exist on the adjacent hillsides, for the placer mines may have proven this to be so, which gives an incentive to the prospector.
   Sometimes in the course of placer working the miner discovers a vein crossing the gulch in the bedrock. His method is plain-he follows it into the hill, or sinks a shaft on the rim at a convenient point, but what of the searcher who has not this good fortune?
   In searching for blind veins, systematic work is usually the most expeditious and satisfactory, in the long run. The first thing to ascertain, wherever possible, is the true or probable strike of the veins of the district. Ordinarily, veins in any particular district have an approximate parallelism, and the direction of strike conforms nearly with the strike of the country rock, if the latter is at all slaty or schistose. Where rocks are mostly massive, that is, not slaty nor inclined to be schistose, the vein system is likely to be complex, the strikes running in many directions. In the latter case-fortunately not the most common, the difficulties of the prospector are multiplied.
   Having ascertained the strike of the country rock, which may generally be observed in the bottoms of the gulches of the district, it may be assumed that the greater number of veins coincide with this strike, and prospecting work would then be directed across this strike. The quickest and simplest way to expose blind veins on a mountainside is to sluice out trenches down the hillside, but this involves the presence of a ditch or reservoir above, neither of which are usually found in new districts. In lieu of this, excavation in pits must usually be resorted to. The place to begin operations is in the bank at the side of the canyon where it is exposed by the stream having cut through it. If good float is found here it should be sought at a point up the hill. If a pit dug several feet up the hillside fails to disclose several pieces of similar rock, the probability is that ore found in the bank at the bottom of the hill did not come directly down the slope, but has drifted down the gulch from some point above with its accompanying debris. Should similar ore be found in the pit first dug, without finding the vein, another should be excavated at a higher point on the hillside. Care should be taken to note the kind of material in which the pieces of detached ore are found and particularly the height above bedrock at which it is found. If this height is found to decrease as excavations progress up the hill, the indications are that the worker is nearing the vein. Generally, too, the pieces of float are found to be larger as the vein is approached. It is the relative height above bedrock, however, which forms the main guide. This is explained by the fact that a piece of ore detached from the outcrop of a vein, whether it be exposed on the surface or not, is, when first broken off, close to bedrock, but it slowly makes its way by gravity down the slope, a process requiring centuries, possibly, and becoming mixed with the other detritus of the surrounding rocks, some of which is finely disintegrated, forming, with carbonaceous matter, soil, the piece of ore gradually reaches an increasingly greater height from the bedrock as distance from its original position is gained. This process goes on much more rapidly on a steep slope than on a gentle one.
   The search for the hidden vein is simply a process of following the detached fragments up hill to the source of their origin. This is the general principle underlying the quest of minerals of all kinds where the veins are buried from sight. All trenches should be made to bed rock, particularly as the work progresses up the hill, that the worker may not be misled and pass over the vein for which he is looking. Where no float occurs on the hillside the difficulties are multiplied, and the chance for success is greatly lessened. In such cases, the absence of float may be due to the fact there are no veins, but some veins have a crystallized or comb structure and the outcrops disintegrate into material so fine as to attract no attention from the prospector. In the search for gold this condition is met in a measure by panning carefully for gold, and it will be found, where gold exists; it will act in much the same manner as float quartz as above described, though the quartz will rise to a greater height above the bedrock in a given distance than the gold. This indicates that the prospector may have to search much further to find the outcrop by following the gold than rather than the float. 
   The most satisfactory method of prospecting extensively for blind leads is by means of a tunnel with crosscuts, but this contemplates the expenditure of a large amount of capital-either money or labor, or both, and the prospector usually being only  able to supply one of these essentials, does not adopt a method requiring so large an outlay. Moreover, the tunnel is only justified when the outcrop of one or more valuable veins has actually been found.
   The prospector should be a close observer and a good “judge of rock,” that he may distinguish the various kinds of quartz or other rock that he meets, one from the other, and not be led to follow worthless rock by being unable to distinguish the different kinds of ore. The safest plan is to crush and prospect for gold, or have it assayed if for silver or base metals.” 

Offline alleyoop

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Re: Old Time Prospecting Methods
« Reply #23 on: June 30, 2014, 10:23:59 PM »
    Thank you very much for your extra work ,and get well quick  <-idea->

Offline tamarackman

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Re: Old Time Prospecting Methods
« Reply #24 on: July 06, 2014, 07:40:02 AM »
so any advances on your prospecting adventures damionwaltz? hope yer still on the hunt.  Thanks for the post EMF great to reread, every tidbit of advice helps and sinks to the bedrock of our consciousness to be mined and pulled out in nuggets of aid when the time is right.  <-good_>

Offline EMF

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Re: Old Time Prospecting Methods
« Reply #25 on: September 20, 2014, 11:52:38 AM »
I found a pocket mining article I don't remember seeing before in the Mining and Scientific Press. Here it is:

From the Mining and Scientific Press,  August 26, 1916

Pocket-hunting Applied to Prospecting By John B. Platts 
                                                                                                                                                                                                                                                                                                           A method commonly used for prospecting hidden veins that do not outcrop seems to be unfamiliar to so- called 'engineer-prospectors.' This is 'rimming' with a pan as practiced by the 'pocket-hunters' for gold. Gold pockets are concentrations near the surface, or at least in the oxidized zone. They commonly occupy a small space such as a vug in a quartz stringer or in a small, partly open fissure.

The gold is usually loose and free from gangue, which is likely to be clay and decomposed rock minerals mixed with oxides of iron and manganese and, in the deeper pockets, with secondary sulphides. In true pockets the proportion of gold to gangue is considerable, amounting to solid metal in extreme cases. Large placer nuggets are probably derived from such pockets. There is abundant evidence that these pockets are secondary deposits derived from near-by low- grade primary deposits. The gold-pockets are found in 'iron seams' and iron-bearing quartz veins and less often in calcite stringers.

 The pocket-hunter pays special attention to yellow spots or streaks in the alluvium, as these indicate a concentration of iron. Sufficient ferrous sulphate may be present to form a gold-pocket and not make a distinct coloration in the soil. Hence in a favorable-looking region or near where pockets have been found in the past, it is customary to do systematic prospecting over considerable areas regardless of the color of the ground. Ferrous sulphate is the most common precipitant of gold chloride in solution in meteoric water, the gold having been dissolved by chlorine set free by the action of oxides of manganese on soluble chlorides, this being the theory of  formation.

The word 'trace' is used by pocket-hunters, meaning the spill of gold in the surface-soil. The process of sampling a trace is called 'rimming' or tracing. When the pocket-hunter finds a yellow spot on an otherwise favorable hill-side, he spades up a shovelful of earth and pans it carefully. The presence of one or two fine colors is enough to cause him to thoroughly investigate the neighborhood. He takes a row of samples along the hill side, three or four feet apart and following a contour. If he is on a real trace several of these probably will show more or less gold, while the end-samples of the row will be barren.

 If a large number show gold, that is, if the trace is wide, it will mean one of three things: (1) that the pocket is some distance up the hill, (2) it is an unusually large one, and (3) the gold comes from a vein in which it is not concentrated in pockets. The first contingency is the most probable, and the third next; big pockets are rare. The pocket-hunter then takes another row of samples a short distance higher up the hill than the first row. It is not necessary this time to take the extreme end-samples much beyond the limits of the trace as shown by the first row of samples.

If the pocket is near-by, the strip of soil carrying gold will narrow rapidly as one goes up hill. If the trace comes from a true pocket it will contract to a width of a few feet as the prospector takes successive rows of samples. Here he must move slowly and cautiously, as the pocket may be in the surface soil and contained in a space no bigger than a shovelful. It is easy to overlook such a pocket, or unwittingly shovel it down the hill.

However the pocket is usually found in the bed-rock. A point will be found where no gold appears on the surface. Deeper digging for the next row of samples will show that the trace is still there, and a careful examination reveals a layer in the soil of a different color to the rest, commonly more yellow. The gold will be confined to this yellow layer and to a narrow strip of it. At this point the experienced pocket-hunter begins to pan the entire gold-bearing streak instead of only samples, to avoid shoveling the pocket over the dump. Inexperienced pocket-hunters lose much gold by neglecting to observe this precaution.

The gold-bearing layer will be found to approach bed-rock as it is followed until it lies upon it, and finally stops at an iron seam or quartz stringer or vein of calcite. After finding the vein that contains the gold, the prospector continues to dig and pan all the gold-bearing material until the pocket or pockets are unearthed. A single stringer will often contain several pockets. If the ground is flat the surface-soil is likely to be deep, and the amount of digging below the surface will be extensive. If the hill-side is steep, the surface-soil will be thin or absent in spots, and when a trace passes over a bare spot it is difficult to follow.

Surface slides often complicate traces. A close inspection of the colors with a lens will tell the experienced pocket-hunter whether a trace is worth following. True pocket gold is rough and ragged, often appearing like fragments of finely branched moss. Smooth grains like tiny seeds or flakes are likely to lead to unprofitable scattered deposits in talc or serpentine.

Pocket-hunters are sometimes embarrassed by over lapping traces, that is, traces from several sources mingled in the same soil. The expert can often untangle over-lapping traces by examining the gold and noting differences in color. Natural gold from different deposits is likely to vary more or less in the color due to alloyed impurities.

Go forth, and fill your pockets!

Offline sunshine

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Re: Old Time Prospecting Methods
« Reply #26 on: September 20, 2014, 09:12:06 PM »
For sure with pocket gold hunting, one has to be organized, persistent and consistent.  It sounds easy, but very difficult to do in the real world.  In the right area, it is very worthwhile for the individual prospector.  I bet there are people doing it successfully and making a very nice living....and keeping very quiet about it. 

Three comments about things that can complicate the search for a pocket.  (1) sometimes one is limited by the size of the claim.  ie. you cannot look further, because it belongs to somebody else, park, Native land, etc.  (2) Sometimes gold comes from multiple sources (multiple pockets).  The gold along the creek or hillside never really stops.  Unless the next source has different looking gold, or the quantity of colors significantly decreases and then increases again, it makes difficult to assess.  (3) the reason for the gold stopping might have nothing to do with a pocket source.  It may be glacial effect or where an ancient channel crossed or recrossed  the current stream.  An interesting read is how the Toop Nugget Mine was discovered in BC (lots of articles online).  It was also in an area where gold stopped, but not a pocket, and instead a change in direction of the older stream. 

I recall there was a book written years ago about pocket hold hunting (if I recall Washington or Oregon) and Glenn Leaver in his book called that one "the bible".  I no longer have my copy to look it up, but maybe somebody else can advise.  The other thing Glenn suggested was the Gold Spear detector was the perfect tool for pocket hunting.  It would save on digging and panning because it picks up on micron gold in the grass roots. 
See my YouTube channel for fun amateur video:
https://www.youtube.com/channel/UCnz8kX6AZOeZbRt0F9XqVJA

Offline EMF

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Re: Old Time Prospecting Methods
« Reply #27 on: September 21, 2014, 12:41:27 AM »
Yeah, like you say, it sounds easy, especially if you never tried it before. I was reading that account above, knowing that the guy probably used a donkey to carry the panning water for him. Just try going up and down the hill to pan the buckets of dirt you haul. And most of the time it is empty ground being tested. The gold spear can be a help in this, but it requires a gold particle density in the ground that is much higher than what panning can find in the begining stages. It should do great following a trail of microgold, but in the Klamath mountains gold coming out of pockets is commonly coarse, making it easier for the gold spear to pass between particles. It is probably better to use it after panning has located the presence of a trace.The pan can reveal one particle of gold in a shovel full of dirt, while the goldspear is not likely to find it diluted with that much soil.

 I remember reading an old timer's article discussing what kind of person can succeed at pocket hunting. First he had to be excessively optimistic. He needed plenty of intelligence, but not too much, a strong back was much more important. That one did not make sense to me until I got some experience. He also needed great patience, and persistence.

At least in this country, as long as it is open to mineral entry and unclaimed, which is a vast area that does cover a lot of pocket country, we are free to pocket hunt the country without claims or licenses as we go prospecting. If small pockets are found, we dig them and move on. For large ones, still no official registration is required, but if you want legal protection for your find during the time of the dig it is better to file a claim on it. And I found another kind of obstacle to those traces too. One canyon I had been prospecting was lined with slide deposits along the walls. No trace following up those walls!

 But I did find one possible pocket location by following veins above the slide zone, where the vein was cut by another and it was all shattered. I panned some dirt from that spot and found some gold. I had to map it and wait for later, much later as it turned out when I got sick. I found it in late summer and the soil was baked hard, and deer season was looming. That one is better left for spring when the soil is soft and there are no potential visitors.

But it is an incredibly fun quest, and as thinly prospected as some places are, no one can with good reason rule out the existence of huge pockets still left to be discovered. At the end of the 19th century a monster pocket was found by a couple of brothers about 35 miles from where I search, 60,000 dollars worth at 20 per ounce. They sold their claim and retired to a good life. Another pocket could never have been found but for a horse kicking up some ground, revealing one nugget. They traced out its source and found two monster sized pockets, one atop the other.

Offline sunshine

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Re: Old Time Prospecting Methods
« Reply #28 on: September 21, 2014, 07:40:38 AM »
Here is the (dumbed up) method to pocket hunt on the cheap that I know:

Pick a line of ground that is about the same height and maybe 1KM long.  Decide the distance between samples, such as every 50M.  Dig each sample hole the same depth, usually just under the grass.  Take the same amount of sample dirt from the hole and dry classify it.  Mark the hole with flagging tape and a number.  Dump the classified material into a big zip lock freezer bag and number it too.  Toss the sample into a backpack and move onto the next hole.  Once the 1 KM line is completed, go back to the start and move up hill the same distance (eg 50M) and run a new 1KM line parallel to the original.  For this line, start 25M in, so your new holes are between the ones below.  Now, this has already introduced a couple of problems: (1) when you classify, you are probably getting some sample contamination from the previous hole(s), in that a small fraction of the dirt was from before, and (2) material changes as you move, making it difficult to get really good similar samples.  Oh well.  This gets you some data which will have to be revalidated later.  Anyway, back at camp (or home), you need to pan out each sample and count the colours and describe in your notes any unique character the gold will have.  Plot the results onto a chart and map, so see if anything is developing from the data.  Ideally, you will see evidence of the count and size increasing and then stop.   On the next trip, you have the place to go to check higher in the hill with smaller gaps between test holes. 

See my YouTube channel for fun amateur video:
https://www.youtube.com/channel/UCnz8kX6AZOeZbRt0F9XqVJA

Offline sunshine

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Re: Old Time Prospecting Methods
« Reply #29 on: September 21, 2014, 07:56:44 AM »
Another couple of other comments.  It would be perfect employment for a couple of summer students (if you have the cash) to take the grab samples for you and they would have not idea about the results.  Secondly, if you are doing it yourself, you certainly get to know the area and will see things that you would not otherwise.  It forces you to walk almost every square inch and you might stumble across interesting trails, cabins or old workings that were not obvious when you walked the area taking "the easy route". 
See my YouTube channel for fun amateur video:
https://www.youtube.com/channel/UCnz8kX6AZOeZbRt0F9XqVJA

 


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