Remote Prospecting?

[Geowizard]

Looking for Eldorado;

Spanish Explorers ventured into North America 500 years ago looking for the Lost City of Eldorado. Fortunes in GOLD and Silver were shipped back to Spain. Spanish Explorers knew what to look for in the features of the land. Many were also trained in recovery and refining of precious metals, namely GOLD and Silver. There are remnants of crude smelter ovens in the creeks near Patagonia, Arizona where early explorers smelted Silver Ore.

Early American Explorers during the late 1800's prospected the Southwest looking for the same things the Spanish Explorers were looking for. Prospectors used a process of sampling creek beds and dry washes for placer GOLD. Then, they followed the placer GOLD up the washes until they found the source of the GOLD.

A rational Remote prospector might make the conclusion that if the old timers followed the GOLD up-hill, that the opposite is true.

Geomorphology;

Over the course of Geologic time, the GOLD that was deposited in the hills and mountains erodes into creeks and washes. The GOLD follows an "Erosion Model".

This premise lays out the direction for Desert Placer GOLD prospecting; Find the LODE GOLD DEPOSITS, apply simple geomorphology and establish an erosion model. Follow the GOLD.

GOLD often is locked up in sulfides. Sulfides eventually decompose and release almost microscopic granules of GOLD. This represents a new paradigm in GOLD prospecting. Traditional panning may NOT be effective in recovery of this very fine GOLD.

Don't go away, there's more!

- Geowizard

[Geowizard]

Looking for Eldorado today;

Considering the exploration work done on, in and around all of the major GOLD deposits and most, if not ALL of the minor GOLD deposits, in the continental US and the developed parts of the rest of the world, the probability of making a NEW discovery is approaching ZERO.

Existing UNDISCOVERED GOLD deposits are referred to as "Blind deposits". These deposits are hidden beneath overburden in the form of rocks and gravel that have eroded from high ground. We cannot "see" them with our eyes.

The challenge to all prospectors including Remote prospectors is finding the right tools to be able to see into the ground. Metal detectors have been around for many years. The technology has improved with the development of microcomputers, low noise amplifiers and improved circuit designs.

The limitation is DEPTH;

Each new generation of detector technology seeks to increase depth of penetration. Limited transmitting power and limited sensitivity of the receivers limit the depth response to inches and not more than a couple of feet.

What do GOLD exploration companies do to overcome this apparent limitation?

Stick around and find out!

- Geowizard

[Geowizard]

It fits in a shoe box;

Thirty years ago, I was prospecting a silver deposit. I was contacted by a Junior Exploration company. They wanted to obtain a lease on the mining claims to look for SILVER!

We negotiated the terms of the lease. A few weeks later, I decided to drive up to the mine and do some looking around. I arrived early in the morning just after the sun came up. In my rear view mirror, I saw another vehicle following right behind. As I reached a wide spot, I pulled over. The vehicle stopped and out appeared a bespectacled gentleman we will call Dr. S. After a brief discussion, Dr. S. explained that he was employed by the exploration company and was there to "do an SP survey". He had an assistant that came along with him to help.

When he opened the back of his SUV, he showed me the equipment he planned on using and explained he had gotten his PhD degree in Geophysics at the Colorado School of Mines. His wife was also a teacher there. His geophysical prospecting system fit in a shoe box! He had done surveys all over the world and became a leading expert in using the SP method to survey sulfide deposits.

The principle of this method is based on the fact that sulfide deposits have similar chemistry as a wet cell battery. When minerals containing sulfides react with moisture in the ground they produce a voltage. All that you need to do a(n) SP survey is a digital volt meter that can measure small voltages in millivolts, a spool of wire and two electrodes.

Stick around!

Next, I will provide details on how to make a DIY SP outfit to measure "Self Potential" or as sometimes referred to as "Spontaneous Potential" so YOU can find buried mineral deposits!

- Geowizard

[Geowizard]

This is all you need;

Wire: Boundary Wire For Electronic Dog Fence.

DVM: Any reasonably good Digital Volt Meter.

Probes: Two probes. The probes can be bought online or hand made. These are the same as used in cathodic protection systems.

You only need 100 feet of the wire. So, spool 100 feet of the wire onto another spool. Connect one probe to the end of the wire hanging off the spool. Connect the other probe to the positive lead of the DVM. Connect the DVM to the other end of the wire.

To measure the "Spontaneous Potential", dig one hole at the starting point and connect one end of the wire. Place one probe on that hole. Unspool the wire 100 feet and dig a second hole. attach the probe to the wire and place the probe in the hole. The probes need to make good contact with moist soil.

Write down the voltage potential at five or more places along a straight line. Use a hand-held GPS receiver to note the mid point of each of the measurements. Higher potentials are an indication of higher concentrations of sulfide minerals.

- Geowizard

[Geowizard]

The SP response;

The DVM should be set to read DC Volts. The measured response will be in millivolts. The more millivolts, the more sulfide mineralization there is in the ground. Readings may range from a few millivolts to hundreds of millivolts.

I use this wire: https://www.amazon.com/Breadboard-B-30- ... 929&sr=8-3

Remember, sulfide minerals are often associated with GOLD.

- Geowizard

[Geowizard]

Improved SP outfit;

I made a wooden box big enough for the wire spool to fit into with an open top and open front. I drilled a hole on opposite sides (left and right) to put a piece of all-thread through to serve as an axle. Nuts with washers can be used to tighten the axle to the "reel". A handle can be made that attaches to the axle like a fishing reel.

A second improvement:

Alligator clips can be attached to the wire to make it easy to clip onto probes and the DVM.

Now YOU can go out and find hidden GOLD deposits!

- Geowizard

[Geowizard]

Drilling deeper;

The World Wide Web allows prospectors from all over the WORLD to come here and read all about the many varied topics related to GOLD prospecting!

In light of that, I would like to share more information that will be of interest to Remote Prospectors all over the World. Anyone that reads about exploration (prospecting) and mining for GOLD has probably come across terms like "Resistivity" and "IP". These are two exploration methods that are used by people seriously involved in exploration for GOLD. In the next few posts, I will provide details of how YOU can make your own geophysical exploration systems and go out and find hidden GOLD deposits just like the pros!

You need some tools;

The tools required are simple hand tools like a screw driver, wire cutters and a pair of pliers.

Materials;

You need to collect wire and batteries.

Preparation;

1. Go back a few posts and make the SP outfit. The SP outfit will be used to read the voltages produced when you use the Resistivity and IP methods.

2. Bone up on basic math skills like adding, subtracting, multiplying and dividing.

The Pima Copper-Silver-Gold Mine was one of many deposits discovered using these methods.


Stay tuned for more details!

- Geowizard

[Geowizard]

Many good examples;

A good example of a company that provides IP and Resistivity surveys is Zonge International.

http://zonge.com/geophysical-methods/el ... arization/

Note: This does not represent an endorsement of any product or service. I am not in any way connected to or receive financial benefit from this company.

Realizing that there are many companies available that sell this equipment and routinely perform these services to exploration and mining companies lends credence to the concepts and theory involved. For further in-depth study, I recommend doing a search online. Books and other reference material can be found online.

- Geowizard

[Geowizard]

DIY hookup;

To measure, remote prospectors need to have a few relatively simple components. The components mentioned earlier will work for the voltage measurement. The only remaining component is a source. For that, several readily available 12 volt batteries can be used.

The batteries can be connected in series to add up the number needed for creating current to flow. The current is usually only one ampere. The current probes are made by digging a shallow hole, laying out a sheet of aluminum foil in two holes and shoveling the dirt back on top of the foils. Sometimes pouring salt water onto the soil will provide better contact with the ground. Current is measured and recorded after connecting the power (batteries) to the two foil sheets. Be sure the meter is connected with the batteries and selected to measure the current. Good practice suggests using low voltages and making all connections with the batteries disconnected. Adding a toggle switch to the current circuit simplifies turning off the battery voltage.

The value is the distance between the two electrodes and is used for the placement of the other electrode pair that measures voltage.

Look at the drawing in the link above to get an idea of the arrangement of the probes.

The two current probes can stay in one location and the voltage probes can be moved in increasing steps along a line. If each pair of probes are feet apart, then the steps are foot steps.

In the next installment we will wrap this up.

The measurements can provide prospectors with information about the subsurface to depths from a few feet to hundreds of feet!

Stay tuned for the final episode.

- Geowizard

[Geowizard]

The final touches;

We can call the "measurement" it receives then produced in the earth caused by the earth.

Another point is that as the receiver gets farther away from the transmitter, the voltage at the receiver will get smaller. The measurement compensates for the volume of earth.

Using the dimensions, a correction can be made.

Example:

If we are using a probe separation 0 feet and we have moved the receiver;

So... If you had a current of 0 amps and a voltage of 0 volts.

Note: In order to keep the numbers in the realm of "usable" numbers, the result may be divided. So, in this case, dividing by 0. To be consistent always divide the result.

You can plot the results on the illustration at the respective dot and the given pair. Repeat the process for all of the possible spacings to form a picture of a vertical section of the earth!

Note: As in any technical endeavor, there are purists that would add "pi" to the equation. If you are only using this for your own purposes, multiplying your answer by pi doesn't change the relative highs and lows that represent a potential anomaly. Most of the World which has a HIGH.

Now, YOU can go out prospecting to find GOLD!

- Geowizard