Sep 30 2013
Mammoth Resources Corp. is pleased to announce results from bottle roll tests on 23 drill hole samples from the 2008 Masupari Gold drill program (refer to the company's press release dated July 27, 2013, or the company website for drill locations) and 5 surface samples from the Los Carneritos target area on the company's Tenoriba project in the Sierra Madre precious metal belt in southwestern Chihuahua State, Mexico.
The tests were conducted by Inspectorate & Acme labs with sample preparation performed in Hermosillo, Sonora, Mexico and the assaying performed in Elko, Nevada. The results of these tests were reviewed by Dr. Efrén Pérez Segura at the University of Senora, Hermosillo, Mexico, who noted: "with a few exceptions gold shows an excellent recovery in the oxide zone up to a depth of sixty vertical metres. Thus, the gold & silver in the oxide zone is most likely to be recoverable by cyanide heap leach." Dr. Pérez also noted that: "The recovery in the oxide zone is generally greater than ninety percent. The most interesting is the speed of the recovery. The gold recovery is greater than fifty percent in twelve hours. In general there is a clear relationship between recovery and depth of the samples. The greater the depth generally the lower the recovery. This relationship appears to be a function of the depth of the oxide and primary sulphide zones in the areas where the samples were taken." Dr. Efren's entire report plus a technical report of all historical and recent work on the Tenoriba property performed by Mammoth Resources will soon be available on the company's web site.
Thomas Atkins, President and CEO of Mammoth Resources commented on these results, stating: "We were originally encouraged when the microscope work, performed on core samples by Dr. Pérez, suggested the possibility that these samples contained free gold. Based on these results we sampled the core more extensively for depth and a variety of gold grades, plus a number of surface samples, and performed the cyanide bottle roll tests. The results from this work give us further encouragement that precious metal mineralization at Tenoriba has the potential to be extracted via heap leach processing. This has huge implications on the economic grade potential of a deposit where precious metal values in surface rock chip samples are readily encountered over a 15 square kilometre area and where attractive precious metal values had previously been encountered to 100 metre depths in drilling. It's our intention over the coming months to further advance metallurgical tests to enhance our confidence that mineralized rock at Tenoriba may be processed by heap leach."
Bottle Roll Test Results and Analytical Processes:
Twenty-three core samples and 5 surface samples were selected from the Los Carneritos target area, for cyanide leach testing. Inspectorate & Acme lab's AuAg-1000-CN method was selected for this work with the Inspectorate bottle roll method applied for a period of 72 hours with samples taken every six hours. The first step in this process was to establish a head grade for the core samples (many of which were quarter split), plus rejects of the five surface samples through assay analysis by Inspectorate lab for gold and silver using Inspectorate's Au-IAT-AA & Ag-AR-TR methods. These assay results were compared with the original ALS Chemex lab results from samples taken by Mauparia Gold in 2008 (Table 1). As suggested by Dr. Pérez, from his prior microscope work, a nugget effect can be noticed in various high grade samples in Table 1.
Following performing the assay analysis on samples, a 1000 gram sample of the material from each sample was crushed to under 200 mesh and sent to Inspectorate's Elko, Nevada for the 72 hrs acid leach test (AuAg-1000-CN ). The recovery was calculated using Inspectorate's gold and silver head grade assay results (Au-IAT-AA & Ag-AR-AA-TR). A graphical plot of results from the oxide zone above 60 vertical metres and the Primary Sulphide Zone at depth are illustrated in figures 1 through 6 for 6, 24 and 72 hours intervals for both the currently interpreted oxide and primary sulphide zone from the historical 2008 drill core from the Masuparia diamond drill program. Where recoveries are greater than 100 percent, this occurs as a result of the recovery calculation being performed using the head grade from the quarter split assay and not with a residual assay of the leached 1,000 gram pulp used for the bottle roll tests. The drill core was stored in core boxes in a sheltered core storage facility since 2008.
Qualified Person / Quality Controls:
Richard Simpson, P.Geo., Vice-President Exploration for Mammoth Resources Corp. is Mammoth's Qualified Person, according to National Instrument 43-101, for the Tenoriba property and is responsible for and has reviewed any technical data mentioned in this news release. Analysis was conducted by Inspectorate & Acme labs with sample preparation performed in Hermosillo, Sonora, Mexico and the assaying performed in Elko, Nevada.
Assay Methods & Preparation:
SP-RX-2K sample preparation whereby up to 2.0 kilogram sample dried up to 24 hours, crushed to where greater than 70% -10 riffle split to a 250 gram sample and pulverized to greater than 85% passing 200 mesh.
Au-IAT-AA gold assay whereby one assay ton by fire assay with Atomic Absorption finish. Assay limits between 0.005 - 10 ppm. Over limits are analyzed by gravity finish.
Ag-AR-AA-TR silver assay whereby Aqua Regia - Atomic Absorption. Assay limits between 0.1 - 200 ppm. Over limits are analyzed by gravity finish.
AuAg-1000-CN analysis whereby a 1,000 gram (-200 mesh) +/- 10% sample is weighed to the nearest 0.1 gram, the weight is captured. The samples are transferred into an appropriate vessel. A CN/NaOH solution is then added to the vessel, and the vessel is securely sealed. The vessel is loaded onto a Bottle Roller and "rolled" (agitated) for 24 hours. Some solution is then decanted into a test tube, and centrifuged if necessary. The solution is analyzed for gold and silver on an Atomic Absorption Spectrometer. Results are uploaded and automatically calculated.
Press release avilable from http://www.marketwired.com/
Source: http://www.mammothresources.ca/