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Showing posts with label weathered. Show all posts
Showing posts with label weathered. Show all posts

Friday, November 11, 2011

The Benefits of prospecting during Cold Weather

A snowy owl in flight during cold weather, one of the best times for prospecting.



The greatest benefit of prospecting during cold weather is there aren't any black flies around to gnaw on your bones. There are also many other benefits, probably the second most important is there aren't any mosquitoes around either. These two critters can make prospecting during the warmer month’s sheer hell. Another critter that is missing during the cold months is snakes. Many snakes are harmless, but the onesyou are apt to encounter while prospecting may not all be. It is the venomous snakes like copperheads, coral snakes, cottonmouths and rattlesnakes that can raise hob within any prospecting expedition.  For the most part even bears go into hibernation during the coldest months of the year. 

That leaves some other critters that might remotely be a bother, but only members of the deer family and the mountain lion are truly dangerous.  Usually deer try to avoid contact with humans, but during rutting season in the late fall male deer have been known to attack humans.  I once had a late fall encounter with a bull moose, a member of the deer family that could have been dangerous, but the moose didn’t like the smell of my companion that I’d been after for two weeks to take a bath.  The other dangerous animal is the mountain lion; they look upon humans as lunch.  Most mountain lions are confined to really wild areas in the western United States or the Florida Everglades.  They are very rare, but I observed one in Connecticut about thirty years ago.  According to the Department of Environmental Protection in Connecticut there weren’t any mountain lions in the state.  This spring one was killed on the Merritt Parkway, and another was observed by a canine control officer in northern Connecticut.

The perfect thing to go prospecting in during the winter.  Vehicles like this are used extensively for prospecting in Canada and other cold places.  This is a prototype that was built in Montana during the 1970s.
Photo by Gyre


The greatest benefit of cold weather prospecting is you can see so much further when the trees are bare.  One of the greatest problems facing a prospector is being able to find bedrock.  No leaves or other vegetation make it so much easier.  If you are panning for gold in a stream you can still do so just by wearing rubber gloves.  When I was prospecting in the cold weather I used to wear the bright red gloves that were covered with rubber, and were insulated.  They kept the cold water out, and the heat in.

It’s also much easier to get around in the bush or muskeg when the ground is frozen; in fact in some places where you want to prospect can only be approached during cold weather.  You don’t want to get into muskeg during warm weather, you’ll still be there.

Even if you are not out prospecting it is still a good time to plan your next expedition by studying the literature about the area where you intend prospecting, and laying your plans.  Remember there are plenty of other minerals worth looking for besides gold.

Wednesday, December 15, 2010

Hard Rock Prospecting



Prospecting in hard rock is much different the prospecting in the bed of a stream all though valuable minerals are often found by tracing a trail of specific minerals up a stream until you reach a point where the minerals vanish. When you have reached this point you start looking at the bedrock to see where it had weathered from. Hard rock prospecting is much more complicated than finding placer deposits; it is also much more observational. In this case gold and the other valuable minerals are encased in rock of one sort or another. This enclosing rock is called by the German name “Gangue” a useless rock enclosing the valuable minerals that you are looking for. While quartz is the most common gangue mineral there are plenty of others like calcium carbonate, barite, fluorite and list goes on.

Gold on Quartz     Rob Lavinsky Photo

In many respects hard rock prospecting is a science of whys, why is that rock discolored, why is that water discolored, why is that vegetation stunted are only a few of the many things prospectors look for in the field. A good prospector will examine every outcrop of rock in the area where he is prospecting looking for signs that it might contain a valuable mineral deposit. The basic tools they uses for finding minerals in the hard rock are a geologists pick, and a magnifying glass usually a loupe having 10X. magnification.

The most common indicator of a valuable mineral because it looks exactly like rust, because it is rust, iron oxide that is called a gossen. Just like many other words used in mining and prospecting is derived from German in this case the word gossen means “iron hat.” This is caused by the weathering of iron bearing minerals usually pyrite, but pyrite often contains other metals in what is called a solid solution series. Because they are so obvious finding a gossen nowadays is virtually impossible.

Iron Staining (gossen) on the wall of Kidd Creek Mine Timmins, Ontario   NOAA

The most sought after metal and prospecting is gold, and the old saying goes, “Gold is where you find it.” Although it is usually found in quartz veins and stringers throughout any rock that is been affected by hydrothermal activity gold can also be found in many many other types of rocks. The world's largest gold deposits are found in the Witwatersrand in South Africa. For over a century the source of the gold has been debated, but it has been recently discovered the gold deposits in the Witwatersrand come out of fossil remnants of an ancient mountain range.

When he is in the field the prospector is always looking for rocks that are discolored by the action of hot water, rocks that are deformed, faults in the rock that are often the channel for mineral bearing hot water. When he finally finds an area that looks promising the very first thing he does is to collect several grab samples across the width of the presumed mineral deposit for later analysis in a lab. If the results are promising he will go back and chisel a channel right across the vain in several different places. The samples from each vain are kept separate and are also sent to a lab for analysis.

Prospectors in northern Chile

Sometimes it is virtually impossible to find any outcrops of rock in this case the prospector has to dig down through the overlaying soil until he reaches bedrock where he may find some viable mineralization by observing some of the indicators that are visible above the soil.

Although hard rock prospecting can be a one-man job more often it is left up to a team of explorers each of whom has his own specialty that is generally led by a geologist or geophysicist. An exploration team like this is capable of finding deposits of gold and other metals in many places that are beyond the capabilities of the single prospector.

Copper Ore   Hannes Grobe

One of the things the prospector always has to keep in mind is the odds are stacked against them because for every showing of ore only one in about 300 will prove to be viable for constructing a mine. There was a book published in the late 1900s titled, "Gamblers Ruin" a how to book about nine evaluation.although this particular book has been long out of print there are several good books on the subject that are still available with many of them up to date.