10/8/21 | 500 & 240 Foot Levels
During the month of September 2021, five (5) sill channels were cut from the 500E Drift during rehabilitation and rail installation. These channels targeted the remnant vein exposure in the sill. It is believed that no mining has occurred below the 500 level in this area of the mine. Two samples, BH500SEB-017-BKXCHK and BH500SE-017-TRG, were taken in place of a traditional sill channel, where the vein was not accessible. BH500SE-017-TRG was a trench with fractured rock and muck and BH500SEB-017-BKXCHK was a back channel taken above the trench in the visible vein. BH500SE-SQL was 100g of certified reference material SQ88 for quality control/quality assurance. Additionally, Samples were cut from mineralized intervals of cores BHU21-07, BHU21-08, and BHU21-09. These core samples are cut in half with a tile-saw so that one half remains on-site for archive purposes. Channel samples were cut utilizing a battery-powered angle grinder, chiseled out and collected into sealable sample bags.
All of the samples were shipped to American Analytical Services, Inc. in Osburn, Idaho on September 21st, 2021 and were received September 23rd, 2021. Fire assay analysis with gravimetric finish was performed and the results of the analyses were received on October 8th, 2021. The results are presented in Tables 1 & 2, from Analytical Job No.: BFM_09232-1-F.
All cut samples are 1 inch wide, .75in deep, and a reported length (unless otherwise stated)
MAG stands for Magnetite, a magnetic mineral
TRG stands for Trench Grab, only one sample utilizes this label as the sample was pulled from a trench of vein material, not explicitly cut.
500SE stands for 500 Level Sill East
500SEB & BKXCHK stand for Back Channel Cross-Check Sample
SQL is random letter assortment designation for the QA/QC certified reference material sample
BH500SE-010: 24in channel, from the Hanging wall rib to the center of the drift, of heavily mineralized QSP alteration, dominantly pyrite.
BH500SE-011: 20in channel, from the center of the drift, massive coarse pyrite and some QSP alteration surrounding it.
BH500SE-012: 22in channel of massive coarse pyrite from the center of the drift.
BH500SE-015: 12in channel of fine to medium grained pyrite with mineralized alteration and possible chalcopyrite; located in the center of the drift.
BH500SE-016: 16in channel of fine to coarse cubes of pyrite along with mineralized, silica-rich alteration. Some chert seen in the alteration. Possible chalcopyrite.
BH500SE-SQL: 100g of RockLabs Certified Reference Material SQ88.
BH500SE-SEB-017-BKXCHK: 10in channel of visible vein in the back, directly above the trench in 017-TRG. Fine grained pyrite with minor chalcopyrite and a blue-green chalcanthite precipitate.
BH500SE-017-TRG: 15in of fractured rock and muck from a 2ft deep trench in the center of the drift, mostly mineralized alteration and some vein material.
BHU21-07_15.5-16.0_MAG: 6in interval with visible magnetite stringers that magnets are attracted to, no other mineralization seen.
BHU21-07_72.0-74.0_H: 2ft interval of mineralization including galena, chalcopyrite, pyrite and quartz. Chert-like quartz seen along with some red hematite.
BHU21-07_78.5-79.0_H: 6in mineralized interval with pyrite, galena, chalcopyrite and quartz surrounded by crumbling QSP alteration.
BHU21-08_21.0-21.75: 10in interval of fine pyrite and vuggy quartz
BHU21-08_27.75-28.0: 3in veinlet of coarse-grained chalcopyrite along with galena, pyrite and quartz.
BHU21-09_24.0: 2in veinlet of pyrite with chalcopyrite, hematite, and vuggy quartz.
BHU21-09_25.5-26.0: 6in interval encompassing a 2in veinlet of pyrite, chalcopyrite and quartz. Multiple pyrite stringers surround it.
Observations, Discussion, and Continuing Work
With regard to the 500E Sill channels, it is difficult to characterize the vein and the potential for producible grades of ore. The vein seems to be sporadic, undulating and changing dip/strike frequently. The vein appears to be within the foot-wall under the first large stope of the 500E level and further inby the raise to the 430 level it appears to be in the hanging-wall. To sample the vein in the ribs, a small core drill setup or jack-leg test holes may be the only way to successfully reach the vein and provide data. Another factor considered is the amount of muck compacted on the sill along with the large amount of water in the drift. This creates an extremely difficult sampling situation where trenches must be dug deep down and the water pumped out.
With regard to the 240 core samples, the smaller veinlet intercepts appear to be of lower grade; however, identifying these veinlets is extremely beneficial as they may swell and create mineable targets at depth; naturally, further core drilling at the deeper stations is planned and has already commenced on the 350ft level. Additionally, the data indicates that magnetite may be un-related to the main ore-bearing mineralization.
Continuing work will consist of sampling the remaining cores from 240 and the forthcoming cores from 350, continuing the 500E sill channel sampling, and additional exploration sampling as areas are explored and deemed safe.
QA/QC Program Notes
The certified reference material sample, BH500E-SQL, returned a value with a -2.1% relative standard deviation from the certified value (negative meaning the returned value is under that of the certified value). This is categorized within the top category or “good” for gold assays with a concentration over 1.0 opt. As more certified reference material samples are sent out, the database will grow, displaying the accuracy and precision of the assay labs, further lending confidence to our assay values as appropriate for modern data analysis.