Status: Under Option to Vista Minerals Pty Ltd.
Millrock considers the Stellar Project to be a highly prospective property with excellent exploration potential for the discovery of significant, bulk-mineable copper/gold deposits including porphyry Cu/Au, skarn and intrusive-related gold.
Location and Setting
The Stellar Project is located in the Valdez Creek Mining District in the Central Alaska Range about 300 km (186 mi) north of Anchorage. The terrain is mountainous to hilly and development logistics are excellent. The Denali Highway is located approximately 13 km (8 mi) to the south and the Richardson Highway is located less than 45 km (28 mi) to the east.
Millrock Alaska LLC, a wholly owned subsidiary of Millrock Resources Inc., holds 211 contiguous State of Alaska mining claims in the district (Figure 1).
Geology and Mineralization
The Stellar Project straddles the Yukon-Tanana and Wrangellia terranes. The Upper Paleozoic Yukon-Tanana terrane is host to numerous metal deposits and occurrences including Cu-Au porphyry, Cu-Mo porphyry and volcanogenic massive sulfide types in both Alaska and the Yukon. The Wrangellia terrane docked with North America in the Cretaceous and consists of many different rock types of Later Paleozoic to Mesozoic ages. The accretionary processes and thermal effects of the long lived Wrangell volcanic event during the Cretaceous are responsible for many Cu-Au porphyry deposits throughout southern and central Alaska.
The Stellar project area contains multiple copper and/or gold prospects (Figure 2) including the Zackly prospect, a documented gold-copper skarn. At Zackly, geologic observations suggest a nearby altered diorite could potentially be part of a larger mineralizing system. Moderate chlorite and sericite alteration was noted in intrusive rocks with associated copper sulfide (bornite and chalcopyrite) mineralization.
The Zackly area was explored from 1981 to 1994 by several companies. Programs included surface sampling, trenching, geophysics and both core and reverse circulation drilling totaling approximately 40,000 feet (12,192 meters) in approximately 85 holes. Two historical estimates (1982 and 1987) have been completed for the Zackly “Main Skarn” zone, one of three known mineralized skarn zones located along the Zackly skarn trend.
Note to readers: the numbers presented in the table below are historical in nature. Readers are cautioned to carefully read the explanation and cautionary statements that immediately follow the tables.
Zackly “Main Skarn”: 1987 Reserves*†
Zackly “Main Skarn”: 1982 Reserves**†
*From Resource Associates of Alaska, 1987, 1987 Final Report: Exploration Results from Zackly Gold-Copper Skarn Prospect Alaska Range, Alaska Volume I, 141 p. This study utilized a modified polygonal method based on data from core drill holes, reverse circulation drill holes and surface trenches. Calculations were determined using a drill hole radius of influence of 200 feet and a 0.05 opt Au cutoff. In 1986 metallic screen assaying methods were employed on available reject samples from the 1982 Zackly drilling campaign. These data were not utilized in the 1987 study which constitutes the most recent reserve/resource study known to Millrock.
** From UNC Teton Exploration Drilling, 1982, Geology of the Zackly Gold-Copper Skarn Prospect Alaska Range, Alaska Final Report 1982, 281 p. Study utilized a modified polygonal method based on data from core drill holes and surface trenches. The radius of influence for drill holes was half way to adjoining mineralization or 200 feet around an intercept. Currently, the Company has access to the complete 1982 study only.
† The historical resource estimates mentioned from the 1987 and 1982 reports are for historical purposes only and are not compliant with CIM definition standards for Mineral Resources and Mineral Reserves, as defined under NI 43-101. The historical reserve estimates were prepared prior to the implementation of NI 43-101 and use terminology different from and not compliant with current reporting standards, including the terms “indicated and inferred reserves” which incorrectly implies economic viability. Reliability of the historical estimates reported in 1987 and 1982 is suspect based on poor recovery of the diamond core drilling and also the rotary drilling between 1981 and 1987 resulting in significant core loss within areas of mineralization, together with selective sampling, wide drill spacing between sections and the lack of a QA/QC assay protocol (Eden, K. A., 2011, Stellar Property, Valdez Creek Mining District, South-Central Alaska: NI 43-101 Technical Report, January 8, 2013, 113 p.). Though considered relevant by the Company, these historical estimates are not considered reliable. Dr. Eden, a qualified person as defined in NI 43-101, has done sufficient work to determine that it is not possible to use the historical estimates as current mineral resources or mineral reserves and the Company is therefore not treating the historical estimates as current mineral resources or mineral reserves. He has determined that it will be necessary to re-drill the holes to verify the historical estimates and to upgrade the estimate to resources that are compliant with NI 43-101, as described in Dr. Eden’s technical report which was filed on SEDAR (www. Sedar.com) on January 8, 2013.
Historical conventional soil sampling over the Zackly prospect area defined multiple, large, highly anomalous Cu-Au zones currently untested by drilling. Aeromagnetic anomalies encompassing Zackly extend both northwest and southeast of the prospect potentially reflecting extension of subsurface mineralization.
The historical “Kathleen-Margaret Mine”, located approximately 11 km (7 mi) northeast of Zackly, is also included in the Stellar Project. The Kathleen-Margaret mine was developed on a north-trending, steeply dipping, copper-rich quartz vein cutting volcanic rocks. Vein widths are reported to locally be in excess of 3.1 m (10 ft). Mining of the vein occurred primarily in the 1950’s with a reported production of approximately 4,900 lbs copper (Source: Kurtak, J.M., Southworth, D.D., Balen, M.D., and Clautice, K.H., 1992, Mineral investigations in the Valdez Creek mining district, south-central Alaska: U.S. Bureau of Mines Open-File Report 1-92, 659 p., 2 plates, scale 1:250,000).
Since 2010 Millrock has collected approximately 950 soil, 760 rock (for assay and/or spectral analysis) and 99 stream sediment samples throughout the project area. In 2013 Millrock also contracted for a new airborne EM/mag/radiometric survey over the property. This work resulted in the definition of at least seven additional copper and/or gold prospects and anomalies (Figure 2). These include the Mars prospect, located approximately 6.4 km (4.0 mi) west of Zackly. This prospect consists of altered gabbro/diorite intruding Triassic volcanic and lesser sedimentary rocks, locally containing extensive gossan exposures. The altered zones commonly contain variable copper mineralization. Soil sampling across the prospect has defined a +420 ppm copper anomalous zone measuring approximately 950 m X 1.7 km (Figure 6). Rock samples of altered volcanic rock have returned assays as high as 7.4% Cu. Anomalous gold-in-soil values are common within the area of +420 ppm Cu anomaly including multiple samples assaying +0.100 ppm Au (Figure 7). Assays as high as 1.78 ppm Au have been returned from rock samples. The Mars prospect is bounded on the northwest by a post-mineral(?) thrust fault. Potential exists for the discovery of additional mineralization to the northwest below the fault contact.
The Jupiter prospect is hosted in altered Triassic volcanic rocks near a contact with dioritic intrusive rocks. The prospect, located approximately 1.8 km (1.1 mi) north of the main Zackly skarn, is characterized by east- and northerly-trending, altered, Cu/Au-bearing fracture/vein zones. Soil sampling has defined a +420 ppm copper anomaly measuring approximately 800 m X 1.9 km. Anomalous gold-in-soil values are commonly associated with elevated copper values with assays up to 0.330 ppm Au returned.
The Gemini prospect, located approximately 5.2 km (3.3 mi) north of Zackly, appears to be hosted primarily within Triassic volcanic rocks. This newly discovered prospect was defined in August of 2013, the result of a wide-spaced, property-wide soil sampling program. The Gemini +420 ppm copper-in-soil anomaly, while variable in outline, averages approximately 1.0 km X 1.6 km (Figure 9). Anomalous gold-in-soil results tend to occur coincident with elevated copper values with gold assays typically ranging from 0.150 – 0.250 ppm Au (Figure 10).
The North Moonwalk prospect, located approximately 11.5 km (7.1 mi) north of Zackly, is a gold prospect consisting of altered granodiorite intruding mainly black shale. The intrusive rock and surrounding sediments are commonly altered with local zones of stockwork quartz-sulfide veining. Nineteen soil samples collected from the main altered zone average 1.15 g/t Au over a 400 m by 700 m area. Chip samples of vein material returned assays up to 30 g/t Au. In addition, a stream sediment sample approximately 2 km (1.4 mi) downstream from this area assayed 0.24 g/t Au and was accompanied by an outcrop sample of what appears to be altered and veined sandstone that assayed 23.0 g/t Au. Mineralized samples at North Moonwalk also tend to be anomalous in bismuth, arsenic and antimony, common trace elements associated with “Tombstone-style” gold deposits and prospects found within the Tintina gold belt of Alaska and the Yukon.
In 2012 Millrock acquired the majority of the historical Zackly data, including drill hole logs and reports. The company has digitally captured these data and imported it into its Geographic Information System. This effort has added to the understanding of the prospect geology, resulting in the definition of new drill targets. Proposed drilling at Zackly is recommended to expand skarn mineralization and test surface geochemical anomalies, both for potential skarn and intrusive-hosted copper-gold mineralization. Re-drilling of the Zackly “Main Skarn” will be required to determine if the historic estimate is in fact valid, and able to meet the requirements of NI43-101 for resource calculations.
The Mars, Jupiter and North Moonwalk prospects are considered drill-ready with multiple defined targets. Those targets could be refined through additional detailed geologic mapping, particularly at Mars and Jupiter. Additional sampling and geologic mapping is recommended for all other prospects with possible follow-up drilling dependent on results.
Agreement and Terms
Millrock owns a 100% interest in the Stellar property, subject to a 2% NSR royalty for gold, silver, platinum, palladium, and rhodium, a 2% royalty of Gross Uranium Final Sales and a 1% NSR royalty for all other minerals payable to Altius Minerals Corp. Millrock is currently seeking potential partners interested in an earn-in style Option to Joint Venture or Option to Purchase Agreement on Stellar. If desired, Millrock can serve as operator on behalf of an earn-in partner.
“THE TECHNICAL INFORMATION WITHIN THIS DOCUMENT HAS BEEN REVIEWED AND APPROVED BY GREGORY A. BEISCHER, PRESIDENT & CEO OF MILLROCK RESOURCES INC. MR. BEISCHER IS A QUALIFIED PERSON AS DEFINED IN NI 43-101.”