Goldrich Completes Chandalar, Alaska Phase I Exploration Drilling
Spokane, WA - Nov 30, 2011 - Goldrich Mining Company (OTCBB - GRMC) (the “Company”) is pleased to report the first diamond core exploration drilling on its Chandalar, Alaska gold property has exposed what it believes is a wide-spread system of gold mineralization at intervals from surface to depths of up to 120 meters (about 400 feet). The Company also believes the mass of rock affected by the mineralizing system to be large, as more than 50 gold showings are scattered over about six square miles (fifteen square kilometers), only a fraction of which has yet been drill tested.
The recently completed 25-hole, 4,404-meter (14,444-foot) exploratory program, using HQ size core, tested six prospect areas (see map below) located along a 4-km (2.5-mile) long northeast trending belt of gold showings. The drill cores contain a total of 56 mineralized intervals of 0.5 or greater grams per tonne gold (g/t Au) that average 2.3 meters (7.5 feet) in length and have a weighted average grade of 1.66 g/t Au (see table below). Gold-bearing intercepts were obtained in 72% of the holes, with many having multiple intercepts.
Drilling results draw the Company to focus particularly on two prospects – Aurora and Rock Glacier – which the Company believes are geologically associated and related to the same controlling mineralizing features. Intercepts include:
- 1.5 meters (5.0 feet) at 6.57 g/t Au in Hole LS11-0063 on the Aurora prospect;
- 2.1 meters (7.0 feet) at 6.02 g/t Au in Hole LS11-0041 on Rock Glacier
These and other intercepts listed in the table below are associated with much longer core runs of strongly anomalous gold (> 0.10 g/t Au) between 4.3 meters (14 feet) and 21.3 meters (70 feet) in length.
Also worth noting, while constructing a road to a proposed drill site, the Company encountered two zones of shearing with sheeted and stockwork quartz veinlets, approximately 5 meters (16 feet) and 15 meters (49 feet) wide. These zones are located 135 meters vertically above and 200 meters southwest of Aurora drill holes #61 to #64. Representative continuous chip sampling of these zones yielded assays of 2.8 g/t gold and 2.1 g/t gold, respectively. The Company believes the mineralized Aurora drill hole intercepts may represent an extension of these zones and that additional drilling could extend these zones even further.
While the silver (Ag) values associated with these and most of the other gold intercepts are generally less than 2 g/t, unusually, native silver is observed in one core interval of 0.46 meters (1.5 feet) from 80.01 meters (262.5 feet) to 80.47 meters (264.0 feet) in Hole LS11-0042, which assays greater than 690 g/t Ag (> 20.1 oz/st Ag [st = short ton]) with only a trace of gold. A second curious silver rich interval occurs in Hole LS11-0040 for 2.1 meters (7.0 feet) from 23.47 meters (77.0 feet) to 25.60 meters (84.0 feet), which returned 397 g/t (11.6 oz/st Ag), again accompanied with only a trace of gold.
The Company believes this silver mineralization may represent a separate mineralizing event within a large and complex precious metals bearing mineral system.
Chandalar’s wide-spread precious metal system is hosted by carbonaceous, pyrrhotite-arsenopyrite-pyrite bearing schist. Significantly, extensive intercepts of hydrothermal alteration manifested by massive chloritization and strong silicification of the schist are associated with the mineralization, and are often geochemically anomalous (> 0.05 g/t) in gold as well. The gold mineralization is believed to be mainly controlled by fractures and shears of various orientations within the schist. Mineralized intercepts have now been intersected by drilling over a vertical elevation difference of 550 meters (1,800 feet), with the lowest exposure being in the northeast at the Aurora prospect which is close to the Little Squaw alluvial gold deposit. The metamorphic strata hosting the gold are severely eroded at the higher elevations and either dip to the north or are down faulted, or both.
Additional core drilling is necessary to assess the continuity and extent of outcropping and any projection from the gold-mineralized intercepts as well as determine the limits of the mineralizing system.
In addition to drilling, the 2011 Chandalar gold exploration program included a grid soil sampling survey consisting of 1,150 samples for multi-element analyses. All of these analytical results are pending.
Also, a detailed airborne magnetometer survey was recently completed over the Chandalar property by Fugro Airborne Surveys Corp. of Toronto, Ontario, and is being evaluated by the Company. Preliminary data indicate a series of magnetic anomalies, some of which are clearly associated with areas of known gold mineralization. Of particular interest is a large anomaly on the north flank of the Aurora prospect.
The Company will integrate results from the soil sampling with the geophysical data and Phase I drilling results to define the next round of exploration drilling.
Bill Schara, CEO of the Company commented: “While the complex geology makes Chandalar a challenging project, we believe we have made good progress by encountering numerous significant gold intercepts in our initial core drilling program and materially increasing our geologic knowledge. We look forward to building on this season’s accomplishments as we plan the next stage of exploration drilling, which we expect to focus more sharply on the Rock Glacier/Aurora prospect area.”
The Chandalar drill program and sampling protocol were managed by Goldrich. The HQ diameter diamond drill holes were generally sampled using a five-foot sample length and overall core recovery averaged greater than 90%. Six quality control samples (one blank and five standards) were inserted into each batch of 120 samples. The drill core was sawn, with half sent to the ALS Minerals sample preparation in Fairbanks, Alaska, where the samples were prepared for assay and then sent to the ALS Minerals Lab in Sparks, Nevada for analyses. Gold was analyzed by fire assay and Atomic Absorption Spectrometry finish and a four acid sample digestion with Inductively Coupled Plasma Spectrometry method was used to analyze a full suite of elements. Samples were securely transported from the project site to the ALS Minerals preparation laboratory in Fairbanks via chartered aircraft hired by the Company.
Donald G. Strachan, Certified Professional Geologist and Goldrich’s contracted project manager for Chandalar, managed the drill program and confirmed that all procedures, protocols and methodologies used in the drill program conform to industry standards.