I am a petroleum geologist who has been advancing the Great Basin geological survey initiated by Shell Oil Company in the early 1950’s, since organizing Cedar Strat in 1984. My theory that gold was absorbed onto activated carbon (dead oil in limestone fractures and tiny carbon particles in an organic-rich shale) from gold pregnant cyanide solutions was confirmed when we found elevated (5-9ppm) concentrations of gold in two samples along a 16-mile-long thrust fault contact of limestone thrust over shale. The gold pregnant cyanide solutions are the result of tremendous amount of carbon compounds, including cyanide, that began to be expelled when organic-rich shales, the richest and thickest shales on earth, were pushed into the oil generating thermal window by thrust loading and leaching 45,000 feet of strata for 65 million years.
Thirty additional samples along the thrust fault confirm the elevated gold concentrations in the first two samples. The samples were analyzed with a Niton XRF analyzer calibrated with certified concentrations of gold. However, when ten of the samples were sent to a world-renowned geochemical laboratory in Reno Nevada for certified analyses, they reported that only one sample contains 0.005 ppm Au and that the other nine samples contain less than 0.005 ppm Au.
Fortunately, I attended PDAC and found three other XRF manufacturers willing to analyze the ten samples with their instruments. Last week I received the results from Elvatech who found nearly double the gold concentrations that we found with our Niton analyzer. Elvatech also calibrated their instrument with certified gold analyses.
I am waiting for a response from the Reno laboratory asking them if they would consider treating the samples to desorb the gold from the carbon before running their gold fire assay on them. I suggested milling the samples much finer, enclaving the samples, heating the samples with microwave, striping the gold from the carbon by contacting of gold loaded carbon with hot, caustic cyanide solutions or stripping the gold using ethanol, isopropanol, ethylene glycol, sodium hydroxide and demineralized water or other gold elution processes to extract gold from the activated carbon by desorption and electrowinning.
Do any of you have any other suggestions? If we can certify that we have the gold concentrations that are indicted by our XRF analyses, then our 28th of 35 gold prospects may be the largest gold deposit in the Great Basin of Nevada and western Utah. We found the 35 gold prospects by analyzing only a few hundred of the 6000 shale samples collected by Cedar Strat geologists for oil source rock analyses.
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Thirty additional samples along the thrust fault confirm the elevated gold concentrations in the first two samples. The samples were analyzed with a Niton XRF analyzer calibrated with certified concentrations of gold. However, when ten of the samples were sent to a world-renowned geochemical laboratory in Reno Nevada for certified analyses, they reported that only one sample contains 0.005 ppm Au and that the other nine samples contain less than 0.005 ppm Au.
Fortunately, I attended PDAC and found three other XRF manufacturers willing to analyze the ten samples with their instruments. Last week I received the results from Elvatech who found nearly double the gold concentrations that we found with our Niton analyzer. Elvatech also calibrated their instrument with certified gold analyses.
I am waiting for a response from the Reno laboratory asking them if they would consider treating the samples to desorb the gold from the carbon before running their gold fire assay on them. I suggested milling the samples much finer, enclaving the samples, heating the samples with microwave, striping the gold from the carbon by contacting of gold loaded carbon with hot, caustic cyanide solutions or stripping the gold using ethanol, isopropanol, ethylene glycol, sodium hydroxide and demineralized water or other gold elution processes to extract gold from the activated carbon by desorption and electrowinning.
Do any of you have any other suggestions? If we can certify that we have the gold concentrations that are indicted by our XRF analyses, then our 28th of 35 gold prospects may be the largest gold deposit in the Great Basin of Nevada and western Utah. We found the 35 gold prospects by analyzing only a few hundred of the 6000 shale samples collected by Cedar Strat geologists for oil source rock analyses.
[email protected]
