Hog Heaven Silver-Gold Project Summary
Hog Heaven is a wholly owned silver-gold-copper-lead-zinc epithermal vein-breccia deposit with historical high-grade silver production.
Video featuring the Hog Heaven Project @ The Silver and Gold Summit, San Francisco (Nov 2017):
Location Map of Hog Heaven Project:
The property is located in Flathead County, 55 miles south-southwest of the town of Kalispell, in the northwest portion of state of Montana, USA. The property is easily accessible by driving 10 miles of gravel road from the highway.
Total metres historically drilled on the project is 57,498m from 722 drill holes as rotary, reverse circulation and diamond drill core. Interestingly, while most of the holes were assayed for both silver and gold, 68 percent of the intervals were not assayed for copper and 34 percent of the intervals were not assayed for zinc and lead.
The Plan and Long Section Maps (below) plot the two mineralized zones where most of the drilling has been conducted, the Main Mine Zone and the Ole Hill Zone. Generally, drill depth is fairly shallow and only a few deeper holes were drilled at the Main zone. At the Main mine 40,775m have been drilled with an average drill hole depth of 121m with the deepest hole to 509m. The total number of drill holes at the Ole Hill zone is 380 with an average depth of 43m with the deepest hole to 583m for a total of 16,456m of drilling. Mineralization remains open in several directions and at depth. Most of the drilling was completed as vertical holes to define the near surface mineralization.
Silver Intervals versus Silver Equivalent Intervals Long Section Main Mine Area:
A table of the highlights from the historic assays of silver verses silver equivalent from 722 holes reviewed to date:
Note: The Qualified Person (“QP”) for Brixton cannot verify the drill results reported in the tables above or the other technical information set out in this news release. The precise location of the drill cores from the program is presently unknown and they have not been inspected by the QP, and therefore Brixton has not undertaken any re-logging, resampling or check assays; however, Brixton has no reason to doubt the results and considers the results relevant and suitable for disclosure. Data from the above drill results are historical results and it is unknown what type of quality-control programs were performed at the time. The QP also advises that true width of the above results cannot be determined at this time.
*Silver Equivalent values (AgEq) were calculated using the formula AgEq = $1,200 x Au g/t ÷ 31.104 + $17 x Ag g/t ÷ 31.104 + $3 x % Cu ÷ 100 x 2204.63 + $1 x % Pb ÷ 100 x 2204.63 + $1.20 x % Zn ÷ 100 x 2204.63/$17 x 31.104. This method assumes full metal recoveries. Metal prices used in this calculation include: $17 per ounce for Ag, $1200 per ounce for Au, $3 per pound for Cu, $1.2 per pound for Zn and $1 per pound for Pb. ** These intercepts have incomplete assay data for Cu, Pb and Zn.
Geology Summary: The Hog Heaven Project is located in a field of Oligocene (30.8 – 36 Ma) volcanic and volcano-sedimentary rocks knows as the Hog Heaven volcanic field. The volcanic rocks consist of high potassium dacite-rhyolite flow domes and dykes, ash flow deposits and volcaniclastic rocks. These rock types intrude or unconformably overlie a basement of Late Proterozoic Belt Supergroup strata. The volcanic suite is comprised of a flat to gently inclined volcanic sequence, including a basal ashflow tuff unit, pyroclastic and epiclastic rocks, intrusive and extrusive dacite porphyry, diatremes and a late trachyandesite flow.
Dome and dyke emplacement as well as Ag-Au-Cu-Pb-Zn mineralization was controlled by north-northwest, northeast and northwest-trending extensional faults and fractures. Mineralization is also localized by permeability contrasts, such as the steep, north-trending diatreme breccia-dacite porphyry contacts, within flat-lying permeable pyroclastic and epiclastic units and along the contact between Belt strata and overlying volcanic rocks. Highest grades occur within zones of intense silicification and acid leaching. Mineralization styles include breccia-hosted, replacement, veins and stockworks as well as open-space fill. There is a strong vertical and lateral metal zonation with increasing Au-Cu grades at depth. Within flat-lying ore bodies, a core of Ag +/- Au is haloed by Pb and Zn +/- Cu.
Alteration is characterized by acid-sulphate, with widespread argillic and advanced argillic alteration and vuggy to massive silicification.
Mineral deposits at the Hog Heaven project are classified as Ag-rich high sulphidation type.Geology map and mineralized zones of interest:Geophysical Surveys: Historical ground magnetics, VLF-EM, IP and gravity surveys were completed and the company is in the process of digitizing and reprocessing of these data sets. Planned work includes a deep IP-resistivity and LIDAR survey. The magnetics-VLF-EM and LIDAR survey are expected to help identify structures that may control mineralization and vector new zones of mineralization. The IP geophysical survey should image the known sulphide and siliceous resistive zones and potential expansion area drill testing.
Quality Assurance Quality Control: Brixton has completed assay data entry for all of the drill holes and has developed the first 3d model for the project. The Company plans to collect and submit the previously drilled intervals that were not assay for base metals and analyze for the full suite of elements. In addition a select number of check assays will be analysed for comparative purposes according to industry standards. Ongoing work includes completion of the drill log data entry and a re-logging campaign of select cored intervals is planned. Brixton is also working with a qualified engineering firm to convert the mine grid based historical drill data to Universal Transverse Mercator (UTM) coordinate system.
Permitting: The Company has submitted an initial drill plan to Montana Department of Environmental Quality. Brixton has posted reclamation bonds in the amount of USD$120,000 for its planned exploration drilling and for the transfer of the existing Operating Permit (inactive) from the previous operator.
Resource Estimates: The Hog Heaven project does not have a NI-43-101 compliant resource estimate. The first significant milestone for the Company will be to establish a maiden resource on the project. The Company shall engage one or more Qualified Person’s as defined by the NI-43-101 to author a report when it believes it has completed enough work to provide a resource statement with enough material to generate a positive preliminary economic assessment report.
Other Exploration Targets: In addition to the Main mine and Ole Hill targets, nineteen historic adits and workings have been identified within the area (see geology map at link above). Two of the prospects occur at the contact between the Tertiary intrusive and volcaniclastic rocks, similar to the Main mine. Three of the prospects occur in the Late Proterozoic Belt Supergroup rocks which Mauk (1983) believed to be part of the Revett Formation of the Ravalli Group.Three large gold-silver-in-soil geochemical anomalies have been identified by previous operators. Two of these remain to be drill-tested and the third has only been tested locally.The northern soil anomaly is located about 1.3 km north of the Main mine area and is underlain by Tertiary volcaniclastic rocks. The southern soil anomaly is located about 1.7km SW of the Main mine area and is located near the contact between Tertiary intrusive and volcaniclastic rocks. The Central soil anomaly is located 200m NE from the Ole Hill area and is underlain by Tertiary intrusive rocks and volcanic flows which also have a corresponding geophysical target. Eight geophysical targets have also been identified within an area of 3km by 1.5km. These targets have been defined primarily by magnetic lows occurring along the margins of gravity lows, where one of the targets cover the Main mine area.These targets have a northwest trend coincident with the orientation of a northwest trending interpreted graben structure, thought to control the emplacement of dome complexes and mineralization.
Metallurgical Work: The Company is planning to undertake additional work in order to confirm and expand on the historical metallurgical studies conducted at the Hog Heaven project by the previous operators. During the phase 2 exploration program, two holes for metallurgical studies are planned.
Planned Drilling: Next steps for Hog Heaven include conducting geophysical surveys and resampling historic core/cuttings. The initial 10 holes shall be to confirm some of the previous drilling results and to test the high-grade feeder zones to the Main Mine Zone and the Ole Hill Zone. Phase two drilling will focus on expanding the known mineralized zones, infilling areas of sparser drilling and testing some of the nearby compelling targets. Brixton’s objective is to complete sufficient drilling over the next few years to establish a maiden resource and then rapidly move towards a preliminary economic assessment.
The Hog Heaven mine historically (1928 – 1975) produced 6.7M oz Ag at an average grade of 29 troy ounces of Ag per ton, 3,000 oz Au, 23M lbs Pb, 0.6M lbs Cu from 230,000 tons and an additional 49,700 tons grading 9.35 troy ounces of Ag per ton. The ore was shipped directly to smelters. The mine was operated by Anaconda from 1929 to 1946 and by a lessee from 1963 to 1975.
A Feasibility Study was completed in 1988 by American Mining Services (pre-dating Ni-43-101) using a silver price of US$6.50/oz and a gold price of US$400/oz. A total of 6.4 Moz Ag at 26.6 oz/t Ag were mined and directly shipped to a smelter (1929-’46).
A historic silver and gold resource estimate exists for the Hog Heaven Project:
(1) Based on a historical estimate for Hog Heaven prepared by Gregory Hahn, Chief Geological Engineer for CoCa Mines Inc., a previous owner of the property, in a report titled “Hog Heaven Project Optimization Study” dated May 1989, prior to implementation of National Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI 43-101”) (as disclosed in a prior owner’s resource statement [click to see News Release dated June 22, 2017] and based on diamond drilling. While Brixton considers these historical estimates to be relevant to investors as it may indicate the presence of mineralization, a QP for Brixton has not done sufficient work to classify the historical estimates as current mineral resources as defined by NI 43-101 and Brixton is not treating these historical estimates as a current mineral resource.