Richmond Summit Project

Location


Redstar Gold Corp.'s Richmond Summit project consists of 72, 100%-owned unpatented mining claims covering 2 square miles within the central Carlin trend (sections 16 and 20 of T34N/R50E) in Eureka County, Nevada. The project lies 4 miles northwest of the Mike copper-gold deposit within the Gold Quarry (Maggie Creek) district and 5 miles south of the Carlin gold mine, both areas operated by Newmont Mining Corporation. Lands surrounding the project are largely controlled by Newmont. Gold production and reserves/resources in the Maggie Creek district total at least 29 million ounces, with at least 10 million ounces in the Carlin mine area (including the West Leeville and Pete deposits).

Geologic Setting


The property lies at the southern tip of the Lynn window, an area exposing carbonate (calcareous) rocks in the lower plate of the regional Roberts Mountains thrust fault. Lower-plate carbonates host most of the gold mineralization along the Carlin trend, although mineralization locally extends into the overlying upper-plate rocks. The lower-plate Roberts Mountains formation is exposed within 1,000 feet of the project. Although rocks exposed on the project are dominantly upper-plate siliciclastics, thick sections of carbonates believed to part of the lower plate have been intersected in drilling and are locally exposed as thrust slices within the upper-plate rocks. In addition to this favorable stratigraphic setting, the project lies on the southern extension of the Post fault, which crosses the northeastern portion of the project. The northerly-trending Post fault system is a major structural control to world-class gold deposits in the northern Carlin trend north of the project such as Post-Betze (Goldstrike) and Meikle. The project contains numerous north trending, Late Eocene rhyolite and andesite dikes which follow the Post fault trend. These dikes can be traced north along the Post fault system from the project through the Genesis, Deep Post, Goldstrike and Meikle gold deposits. Carlin-trend gold mineralization occurred during emplacement of these dikes, which are common within the gold deposits. At Richmond Summit, known gold mineralization (see below) occurs along the margins of these dikes and within adjacent wallrock. A regional northeast-trending fault, the Richmond Summit fault, also crosses the project.

Project Gold Mineralization


Carlin-type gold mineralization on the project occurs in several widely-spaced areas within upper-plate siltstones and greenstone along the margins of dikes. The strongest gold mineralization identified to date occurs in the Main Zone, where select surface samples reach 7.75 ppm Au (0.226 opt [ounces per ton]). The mineralization is poorly exposed, but historic sampling in trenches returned 3.048 ppm (0.089 opt) gold over 20 feet, 4.960 ppm (0.144 opt) gold over 10 feet and 3.59 ppm (0.104 opt) over ten feet. Limited drilling in the area (prior to 1991) intersected shallow gold mineralization within 200 feet of surface, including 0.074 opt Au over 10 feet, 0.064 opt over 5 feet and 0.028 opt over 5 feet. The mineralization is hosted in greenstone and shale adjacent to and locally within a north-trending andesite dike and is accompanied by strongly-elevated arsenic (to 2.7%), antimony (to 450 ppm) and mercury (to 3.3 ppm), a signature consistent with Carlin-type gold mineralization. Prior to the 2008 exploration program (see below) the Main Zone had seen limited drilling, with only three holes deeper than 400 feet; the deepest (1,100 feet) is 500 feet from the exposed mineralization.

Other mineralized areas include the Ridge Zone, 1,200 feet west of the Main Zone, which contains anomalous gold at surface to 1.97 ppm in siliciclastic rocks and greenstone adjacent to a rhyolite dike; a float sample from Ridge returned 3.7 ppm. Several other areas contain anomalous gold at surface in siliciclastic rocks and altered dikes, with values reaching 0.755 ppm. Anomalous gold to 0.950 ppm over 5 feet with locally high As, has been intersected in scattered drilling outside of the Main Zone.

2008 Exploration Program

    Summary
    • The 2008 program included trenching, a gravity survey, a ground magnetic survey and eight widely-spaced drill holes consisting of five reverse-circulation drill holes for 4,680 feet and 3 core holes for 3,868 feet.
    • The work defined a dike-filled, north-trending structural corridor extending the full length of the property (one mile); the structural zone is the southern extension of the Post fault system, which localizes world-class gold deposits of the northern Carlin trend about 7 miles to the north; dikes range from rhyolitic to andesitic and are locally strongly altered and mineralized.
    • Drilling in upper-plate rocks within the structural corridor intersected altered dikes with anomalous gold to 700 ppb and arsenic to 2600 ppm.
    • At the Main Zone, where surface gold reaches 7.75 ppm in historic trenching, drilling intersected an argillized and pyritic dike along a north-trending fault; strongly-anomalous gold-arsenic occurs within the dike and in adjacent upper-plate shales; the results are considered evidence of underlying Carlin-type gold mineralization; only one drill hole in the 2008 program tested the Main Zone and it was incompletely assayed; no trenching was completed in 2008 at the Main Zone, which is unexposed.
    • Main Zone Target: An historic drill hole approximately 1,500 feet west of the Main Zone bottomed in a thick sequence of carbonate rocks believed to be part of the lower plate. The intersection of the gold and arsenic bearing dike-filled structure with this carbonate sequence has not been tested and provides a high priority target for future drilling.
    • The 2008 exploration program was completed by Gold Fields Netherlands Services BV, a subsidiary of Gold Fields Ltd.

    Details

    The magnetic survey, trenching and drilling during 2008 identified two, unexposed, north-trending andesite dikes that traverse the entire mile-long northeast part of the property. The andesites were not previously recognized and are distinct from better-exposed rhyolite dikes, which are non magnetic. The western andesite dike zone crosses the main gold zone within 100 feet of the mineralization exposed in historic trenching (samples to 7.75 ppm Au). Only one hole (core) tested the Main Zone but was incompletely sampled; the 1,300 feet hole tested to a vertical depth of 1,255 feet. The hole intersected anomalous gold to 400 ppb with strongly-anomalous As to 2,600 ppm and anomalous but weak Hg and Sb along sulfidized and argillized to silicified margins of an andesite dike and within adjacent shales. Two gold anomalies in the hole exceeding 200 ppb with high As do not have adjacent sample intervals for more than 10 feet on either side of the samples. The andesite dike occupies a newly-recognized north-trending fault, which is apparently a significant control to the Main Zone mineralization. Several 2008 drill holes (e.g., RC3 and RC4) outside of the main zone also intersected anomalous gold (to 706 ppm) with anomalous As (to 1,100 ppm) in and near dikes in upper-plate rocks.

    Exploration Targets

    The results are encouraging in indicating that mineralization is following a significant dike-filled fault along the southern extension of the Post fault system, that strong Au-As "leakage" along the dike extends to the depths tested and that mineralization in lower-plate carbonates could occur at greater depth. The potential for deeper carbonate-hosted mineralization is indicated by an historic hole about 1,500 feet to the west, which intersected limestone from 1,585 feet to the bottom of the hole at 2,700 feet; the limestone underlies greenstone. This deep Main-Zone target is similar to the geology of the world-class Meikle deposit along the Post fault system to the north. Plotting Meikle at scale on cross section and plan through the Main Zone shows that a deposit of its magnitude could easily fit in this target. Further, a broad gravity high in the Main Zone area may indicate the presence of a relatively shallow and thick block of lower-plate carbonates. The target is considered to include the parallel eastern andesite dike zone, which remains untested about 1,200 feet east of the Main Zone dike.

    Considering the strength of surface gold mineralization, the favorable geology, the similarities to productive gold deposits along the Carlin trend, and the location along the Carlin trend, the Richmond Summit project offers an opportunity to discover significant Carlin-type gold mineralization. The presence of gold-arsenic mineralization along northerly-trending dikes is a key vector to potential deeper mineralization and is similar to productive mineralization along the Carlin trend. Redstar believes the project warrants a second phase of surgical drilling at the main zone and elsewhere to test the intersection of altered and mineralized dikes with the underlying carbonate sequence.

2009 Exploration Program

    Summary

    Work in 2009 by Fronteer Development Group (now Fronteer Gold) included:
    • Reconnaissance geologic mapping,
    • Rock-chip sampling (56 samples),
    • Soil survey (877 samples),
    • Trenching at the Ridge zone, Main zone and east of the Main zone (132 samples),
    • Geophysical analysis of 2008 ground magnetic survey,
    • Relogging of the three Goldfield core holes,
    • Conodont dating, and
    • Drilling of 4 holes: 10,230 feet total; holes ranged from 2,216 to 2,777 feet in length and were vertical at the collar.

    Key Findings

    1. Widely-spaced deep drilling confirmed the presence of lower-plate carbonates (Popovich and Roberts Mountains Fms) under the Main zone (one hole) and elsewhere; however, no significant mineralization was intersected. Conodont dating, textures and lithology within the carbonate sequence, and comparisons to lower-plate carbonates elsewhere along the Carlin Trend were used to make this call.

    2. Mineralization at the Ridge zone was upgraded with a ~480-foot long interval of anomalous gold in trench 1, largely hosted in altered greenstone, with gold values in spot samples to 1.97 ppm gold. Other surface samples beyond the trench returned a high of 3.7 ppm. These values exceed the previous high of 676 ppb. Fronteer considered that this mineralization may be controlled by a N45W/45SW fault. Fronteer proposed drill-testing of this structure with holes angled to the east, collared west of the Ridge zone.

    3. A soil geochemical anomaly was identified in the northwest corner of section 16, with values to 385 ppb gold and 84 ppm As. This anomaly is in an area of rhyolite dikes (sills?) which are altered and weakly mineralized (97 ppb gold); a nearby quartz-veined siltstone runs 123 ppb. There has been no drilling in this area. This gold anomaly is the strongest within the Fronteer soil survey. Fronteer proposed but did not complete further work in this area.

    4. Rocks exposed in the extreme northeast corner of section 16 are considered the Rodeo Creek Fm, a transitional unit at the top of the lower plate sequence.

    5. The deep drilling intersected significant thicknesses of intrusive rocks, mostly felsic, quartz+biotite-bearing rocks, which have locally stoped out large volumes of the lower-plate stratigraphy.

Remaining Targets

    Redstar believes that there are three main targets worthy of continued exploration:
    1. Main zone feeder,
    2. Ridge zone feeder, and
    3. Northwest section 16 anomaly.

    Fronteer's 2009 program significantly enhanced the quality of the Ridge zone anomaly, yielding a high of 3.7 ppm. Both the Ridge and Main zones host upper-plate multi-ppm gold anomalies separated by about 1,300 feet. Each zone contains one deep drill hole which is considered to have intersected the lower-plate sequence; however, no significant mineralization has been intersected in these holes. Therefore, drilling to date has not successfully intersected the roots of the two anomalies within the lower plate, assuming that mineralized roots exist. At the Main zone, the shallower 2008 core hole DD3 (incompletely assayed) did intersect anomalous gold to 400 ppb and strongly-anomalous As along the sulfidized margins of a dike. This dike is believed to be the cause of a major north-trending magnetic linear high and the probable fluid path (feeder) for the shallow upper-plate hosted mineralization. Other anomalous zones were intersected deeper in the hole. Viewing the drilling along the trend of the dike, it would appear that Fronteer's one Main Zone hole, FRS1, may have passed into the lower plate east of this possible feeder dike. Further, most of the lower-plate section in FRS1 is diked out. One target, therefore, is to more surgically test the intersection of the mineralized dike with the lower plate on the west side of FRS1's lower-plate intersection.

    Fronteer recognized that the Ridge zone may be inadequately drill tested. Based on the strong gold in their trenching and other surface samples, and the evidence for west-dipping mineralized structure, they proposed drilling two deep holes angled east from the west side of the anomaly.

    The soil anomaly in northwest section 16 reaches 385 ppb Au with anomalous As. Weakly-altered felsic dikes (sills?) in this area contain anomalous gold to 97 ppb, and quartz-veined siltstone nearby contains up to 123 ppb. There has been no drilling in the area.

Maps


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Photos