The recently acquired Cold Springs property is drill ready with great access. The property consists of 19 Federal Lode Claims located just off of US Route 50 in Churchill County, Nevada approximately 80km east of Fallon. It is located in the western Great Basin of Nevada and hosts high-grade epithermal gold-silver mineralization. The property is underlain by mid-Tertiary aged, altered and silicified rhyodacite tuffs and breccias exposed on a hill top. Four large sub-parallel, gold and silver-bearing low sulphidation epithermal veins up to 70m long and 2m wide have been identified within a 500m by 200m area of silicification.
Selective grab sampling to date has yielded high-grade values of up to 69.4 g/t gold and 1,770 g/t silver from the veins and material sampled from historic mine dumps, trenches and workings. There are also indications from historic drilling and surface sampling of widespread zones of strong hydrothermal alteration on the property, often associated with lower grade gold mineralized halos in the wall rock surrounding the veining.
This indicates the potential for both near surface low grade, potentially bulk minable, gold mineralization on the property along with the potential of the high-grade gold in veins.
Limited historic RC drilling has been completed on the property to date. Most of the drilling has consisted of clusters of shallow vertical holes mostly drilled in areas of historic adits and shafts, a number of which were abandoned in underground workings. A number of other holes appear to have been drilled into the footwall rocks below the mineralization and therefore did not test the mineralized exposures on the hill.
There has also only been limited deep drilling on the property targeting the feeder structures to the surface veins. The drilling to date has not adequately tested or located the source of the mineralizing system. The mineralization at Cold Springs requires a systematic exploration approach to unlock the full potential of the property.
Previous geological mapping and drill results indicate that the host tuffs, the large area of silicified breccia and the high grade veins dip west towards the Cold Springs valley and are likely down-dropped beneath alluvium across a range front fault. The mineralization exposed on the hill at Cold Springs is interpreted to be merely the eastern periphery of a larger epithermal system.
A 2018 geophysical survey identified a large resistivity low west of the range front fault in basement rocks beneath the alluvium cover. This is interpreted to be argillic alteration and/or sulphide mineralization surrounding the core of the hydrothermal system.
In October 2018, Silver Range Resources also completed a three-dimensional induced polarization and resistivity survey over a grid centred west of the mineralization and extending for approximately 400 m west of the range front fault.
This survey identified a large, compact zone of low resistivity (< 35 ohm-m) approximately 200 m west of the range front fault and west of exposures of second stage high-grade low sulphidation veins on the west flank of the central hill. This resistivity feature is interpreted to represent argillic alteration and/or sulphide mineralization associated with the core of a hydrothermal system.
Supernova intends to focus its initial drilling program on better definition of the extent and nature of the mineralization on the exposed hill top, work to identifying the potential source of the mineralization and test the identified geophysical anomaly to the west of the known mineralization which aligns with the interpreted geology on the property.
An initial 2,000 m drill program is planned to both test the geophysical anomaly and the prospective area west of the range front fault and begin to define potential resources within the veins and silicified tuffs exposed on the hill. Specific drill targets are currently being defined for an upcoming 2020-2021 program at Cold Springs.
The Cold Springs property is located 80 km east of Fallon and 66 km west of Austin in Churchill County of Arizona. Records from 1935 indicate that the property was explored since the 1860’s while staking records date from 1907. It was explored intensively by G. Peer from 1950 to 1980 with 400’ of shaft sinking, 2000’ of underground drifting and CAT trenching. There have been four rounds of drilling on the property: Phelps Dodge (1981), ASARCO (1983), WX Syndicate (1987-88) and Northern Abitibi Mining (2006-2007) with a total of 47 holes completed. The property was restaked by Silver Range Resources Ltd. (TSX-V: SRN) in 2016 and explored by prospecting, sampling, geological mapping and geophysical surveys in 2016 and 2018. Supernova has optioned the Cold Springs Silver project from Silver Range Resources, see news release dated Aug. 17, 2020.
The property is underlain by a west to southwest dipping sequence of rhyodacitic tuffs, grading from a crystal tuff at lower elevations (Tt-xl) through a lithic-crystal tuff (Tt-lc)to a lithic tuff breccia (Tt-bx) capping the hill on which exposed mineralization is centred. The capping tuff-breccia is cut by internal cataclasites (Tt-cat), likely primary features generated during slumping of an over-steepened hot volcanic pile. Gold mineralization occurs in the upper unit and a portion of the underlying lithic-crystal tuff and consists of two phases of silicification. An early phase is widespread, pervasive and consists of centimeter-spaced quartz veinlets and interstitial quartz flooding. This style of mineralization contains subeconomic gold and silver, averaging 0.113 g/t Au and 2.81 g/t where thoroughly drill tested in the centre of the property. The second phase of mineralization consists of quartz-chalcedony veins, exposed for up to 70 m in the west face of the central hill and up to 2 m thick. These are classic low sulphidation epithermal veins showing quartz after calcite (QUAC) texture, brecciation and annealing, ginguro banding and clots of pyrite and silver sulphides and sulphosalts. Historic grab sampling of these veins returned assays up to 64.9 g/t Au and 1,280 g/t Ag while initial sampling by Silver Range in 2016 returned grab samples up to 20.1 g/t Au and 1,770 g/t Ag from similar material. A vein drill intersection by ASARCO in 1983 (CS83-03) returned 3.05 m @ 4.25 g/t Au.
Silver Range has acquired and analyzed all of the known drill data from the property, covering the period from 1981 through 2007. The area under the central hill on which the high-grade mineralization has been exposed has been extensively tested at shallow depths and deeper holes have been completed to test for steeply dipping feeder veins beneath the hill. The drill data indicates that the precious metal mineralization is shallow, limited to elevations above 1750 m ASL. This finding, together with the fact that all of the major second stage precious metal veins are moderately west to southwest dipping indicates that the mineralization at Cold Springs is peripheral to a larger system, likely down the hydrothermal hydraulic gradient to the west.
Gold mineralization at Cold Springs is truncated on the west flank of the central hill by a north-striking range front normal fault which has down-dropped the western portion of the hydrothermal mineralization to the west. Drill holes west of the fault suggest that bedrock depths beneath alluvial cover are in the order of 60 to 80 m within 100 m of the fault trace. The maroon tuff breccia capping the hill at Cold Springs has been encountered in two angled drill holes; these cut hanging wall rocks, passed through the fault and were completed in barren footwall rocks east of the fault.
In October 2018, Silver Range completed a three-dimensional induced polarization and resistivity survey over a grid centred west of the mineralization and extending for approximately 400 m west of the range front fault. This survey identified a large, compact zone of low resistivity (< 35 ohm-m) approximately 200 m west of the range front fault and west of exposures of second stage high-grade low sulphidation veins on the west flank of the central hill. This zone extends deeper than the detection limit of the survey (approximately 200 m below surface) and has a top at around 80 m, the inferred approximate depth to bedrock beneath alluvium in this area. This zone of low resistivity is interpreted to be a region of advanced argillic alteration enclosing the steeply dipping source of the hydrothermal system which includes the high-grade vein exposures on the central hill. Silver Range considers this zone of low resistivity to be a prime drill target, well supported by geology.