Gold Prospecting Forums - General => General Gold Prospecting Forum => Topic started by: GPEX admin on January 26, 2008, 12:09:19 PM

Title: GPR (Ground Penetrating Radar)
Post by: GPEX admin on January 26, 2008, 12:09:19 PM
On every placer minerís wish list for sure - - has anyone here owned such, used such, or could recommend the more optimum brand, while taking cost factors into consideration?

Title: Re: GPR (Ground Penetrating Radar)
Post by: RocksForBrains on February 25, 2008, 12:53:33 AM
Noticed the unit in the miners mall, and am also curious to hear of anyone's experiences.
Title: Re: GPR (Ground Penetrating Radar)
Post by: C.Morgan on March 13, 2008, 09:25:06 AM

 Strange serindipty. I find this site while seeking a recreational gold property and find people asking about my specialty.  ;D

 I should clarify, I have used GPR systems over the years but have done so exclusively in Arctic oil exploration. I currently am on a barge on the Beaufort Sea on a 3D seismic project.

 We use the GPR units to measure the thickness of the ice in order to safely move our equipment around on it. It is very effective for that.

 I will paste an example of GPR data below.


 The data in the picture is what I see when I have downloaded, mixed it with the GPS positions and picked out the ice points.

 On the left there is dry land and no line is visible. As the unit has moved on to ice, the black line shows up. That is the radar refraction on the water. It is acurate within a couple inches. The depth is listed on the right hand side in meters.

 To put it simply, the frequency is set to refract on water. Ice is very easy to deal with as there is a very distinct difference in density between water and ice. The frequency will pass through the ice and will reflect on the water.

 I then build maps with access in color coding based on ice thickness so that people know which areas may be safely accessed by which units.

 The display shown above is very similar to what is seen on the monitor in the field as well.

 I have not dropped one to the bottom of the sea yet so I must be somewhat good at it.  ;)

 I have only used the GPR units in this application. I have recreationally done placer mining over the years and it struck me this year that there could be some valuable data to be aquired with these units regarding placer deposits.

 Bench deposits and bedrock depth should be fairly clearly identified and mapped with this unit. Having not used it on land, it will take some experimentation to find the ideal frequency settings and some practice to see what deposits look like. There will not be as much distinction between gravel, clay and bedrock as there is between water and ice so the pictures will not be as clear cut as the one I posted above. I see no reason why these units would not be very accurate with the proper settings and practice though. I look forward to trying them out.

 Larry has kindly sold me a property where I can begin my experiments.   ;D

 Of course I still have to get my backside south of the Arctic circle in order to begin. That will be at the least a few weeks away.

 If anybody else has worked with these units in this application and has any tips, I would be more than happy to hear them.
Title: Re: GPR (Ground Penetrating Radar)
Post by: shiver on March 14, 2008, 12:17:30 AM
Welcome C.Morgan!!

Thank you for the very interesting post,   

I would be quite interested in your research into this. If at all possible please do keep us informed on the results of your experiments.

Enjoy a safe trip home,
Title: Re: GPR (Ground Penetrating Radar)
Post by: GPEX admin on March 14, 2008, 03:38:17 AM
Hey Cory.... great post, and welcome aboard.

I'm sure most everyone will be following your experimentations and application of the GPR.  To smoothe the transition from ice/water application to placer, during my hundreds of thousands of hours of research, I have come across a fair bit of data on the GPR's usage in the placer mining world.  A simple Google search will bring up a good many articles on the topic.... and I'm sure for someone like yourself having advanced knowledge on this facet of science, would enable you to sort out the intracies that would otherwise baffle the lay person (self included).

Looking forward to more of your posts.... on this topic and any others you wish to engage in.  And good luck on your claim.
Title: Re: GPR (Ground Penetrating Radar)
Post by: C.Morgan on March 14, 2008, 08:15:18 AM

 I have been searching with google as advised. I have a great deal to learn on this one, but you sure can't beat the internet as a resource.

 The units I have are Sensors and Software Noggin 500Plus. From what I can gather, lower frequencies are ideal. I can drop the frequency on mine as low as 250 MHz, but even lower would give me more depth. I would lose a degree of resolution too though.

 I am chomping at the bit to get back down south to play with this, but of course have to put my current contract first. Surveying is my bread and butter and it funds things such as my experiments.

 The first thing I will do when I get out there is build a detailed map of the claim. With 3D elevations, I will be able to target the areas I want to hit. I want to try to find a variety of formations. A great deal of it will simply be trial and error and repetition.

 I will post my progress as I go over the course of the next few months.

 I look forward to digging more on these forums for mining tips and methods. There is so much to learn.

Title: Re: GPR (Ground Penetrating Radar)
Post by: RocksForBrains on March 14, 2008, 07:44:47 PM
Great to have you here....very cool stuff {cool^sign}
Title: Re: GPR (Ground Penetrating Radar)
Post by: Feldwebel Wolfenstool on March 31, 2008, 06:33:13 AM
GPDR for finding amethyst vugs, ya...but what I think y'all'd MUCH RATHER HAVE, being much more useful, would be the BM-8, the BEEP-MAT.  No-one here EVER uses GPDR for precious metal prospecting...
Title: Re: GPR (Ground Penetrating Radar)
Post by: shiver on March 31, 2008, 01:01:01 PM
That BEEP-MAT does look neat Feldwebel! Scanning the ground 10 feet deep at 30 km/h is quite productive...have you used it?
Title: Re: GPR (Ground Penetrating Radar)
Post by: Feldwebel Wolfenstool on March 31, 2008, 06:47:47 PM
.....'bout 5 years ago, the local MNDM office ran an afternoon course in how to operate the gizmo.  Quite easy to use, actually.  Emits a rather sad, dissappointing sound when hovering over magnetite....but it squeals like a gleeful pig when over precious metals.  It's referred to as a sulphide detector.  They flew a new set of aeromag surveys over the Shebandowan Greenstone Belt, results that they released around the same time.  The new survey is so discrete, the maps actually have a depth component, indicated on the black anomolies they plotted onto the you do is look for all the ZEROES, first, right?  The ones at zero depth....then we went just up the highway here a mile or two, to try them out.  Amazing the resolution of the mag survey.  Part of the course illustrated how you could discrimate a conductive graphite vein from a nearby "cultural anomoly"...a relic auto carcass in the bush, a mere 15-20 feet away....they both appear as conductive bodies on the surface, on the map......ONE BIG DRAW BACK, takes a lot of tequila to run one of these devices, on a steady basis...they have THREE LOANER UNITS, that when can mooch gratis for one week periods...