Brixton Metals Corporation (TSXV:BBB) (the “Company” or “Brixton”) is pleased to announce that it has completed field work at its wholly owned Thorn project in Northwestern British Columbia. In collaboration with the Mineral Deposit Research Unit and porphyry specialist, Brock Riedell, Brixton completed a program of core re-logging, geological mapping and sample collection for whole rock lithogeochemical analysis combined with short-wave infrared spectroscopy (SWIR). This is a cost-effective method to vector for copper-gold porphyry targets. Final results are pending however, Brixton reports its preliminary findings for the program.
Scope of Work for 2018
- Re-logging of 10 core holes from the Chivas Zone with an emphasis on vein types and distribution
- Determine alteration mineralogy patterns and trends at the Chivas Zone using SWIR
- Develop geochemical trends and a 3-dimensional zonation model for the Chivas Zone
- Expand geological mapping north from the 2017 program at the Chivas Zone
Highlights from Mr. Riedell’s work
The Thorn Project provides a district-scale opportunity centred on an incompletely explored porphyry Cu-Au-Mo system at the Chivas area. Support for temporal and genetic links among the various mineralized zones in the district includes the following:
- Metal ratios in soils and rocks show patterns that are consistent with known Au-rich porphyry systems (cf. Einaudi, 1990), see Figures 1 – 4
- The Chivas Zone represents the centre of the known system based on molybdenum to arsenic (Figure 3) and silver to gold ratios (Figure 1)
- Molybdenum to arsenic ratios clearly highlights the exposed Chivas stock (Figure 3)
A distinctive, crowded plagioclase-biotite-hornblende-quartz porphyry of probable quartz monzodiorite composition forms most of the principal Chivas intrusion and is also widespread at the Oban Zone (as host to and as well as most clasts within the breccias), Talisker Zone and Glenfiddich Zone. Relations observed in drill hole THN17-149 indicate multiple porphyry phases are present.
The Ag to Au ratio at Thorn is markedly reminiscent of patterns at the well know Bingham Canyon porphyry located in Utah, USA, where Ag to Au ratio increases from less than or equal to 10 in the porphyry centre to 100-300 near the outer edge of the Pb-Zn-Ag halo. The ratio then drops precipitously to less than 10 spatially outward from the Pb-Zn-Ag zone into the Au-As halo, which contains the Melco and Barney’s Canyon distal disseminated Au deposits near Bingham. The Outlaw gold zone at the Thorn Project appears to occupy a similar position to the Chivas zone. Porphyry-targeting ratios for soils are shown below.
Figure 1. Thorn Ag to Au Ratio in Soils Plot
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Figure 2. Bingham Canyon Ag to Au Ratio Plot (An Analog for Thorn)
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Figure 3. Thorn Mo to As Ratio in Soils Plot
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Figure 4. Thorn Au to Cu Ratio in Soils Plot
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Figure 5. Thorn Cu-in-Soils Plot
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Note the scale of the copper-in-soil anomaly at the Chivas Zone. Cretaceous age quartz monzodiorite intrudes Triassic Stuhini volcanics.
Figure 6. Thorn Au-in-Soil Plot
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Quartz and sulphide-veined fragments were noted within the Oban breccia (Figure 7).
Figure 7. Veined Fragment Within Oban Diatreme Breccia
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Since net movement in phreatomagmatic breccia is commonly upwards (cf. Sillitoe, 1985), these could help predict the location of underlying porphyry mineralization at depth at the Oban Zone. These will be complemented by application of the MDRU “porphyry footprints” metal and alteration zoning model (Halley et al., 2015) to estimate the location and depth of the likely porphyry centre(s). The Oban Zone diatreme breccia is located 4km north from the Chivas porphyry and the Outlaw sediment hosted Gold Zone is located about 4km to the northeast of the Chivas porphyry.
Chairman and CEO of Brixton Metals, Gary R. Thompson stated, “The Thorn Project is an exceptional example of a wide range of mineralization styles and metal enrichment that can form around porphyry systems. Despite having worked the project for years, Brixton continues to discover new mineralized zones and improve our understanding of this district scale system. We are looking forward to final deliverables from this season’s field work that we believe will provide vectors for a drill program during 2019. Clearly, the porphyry stock itself should be properly drill tested in the next campaign.”
Drilling in 2017 at the Chivas Zone targeted the gold-anomalous wall rocks cut material with relatively high pyrite to chalcopyrite ratios and sub-ore copper grades. Higher grades could also occur in “shoulders” of the exposed porphyry to the southwest or northeast. The Fugro magnetics and Mo-in-soil both suggest the stock remains open to the east and southeast.
Mr. Sorin Posescu, P. Geo., is a Qualified Person as defined under National Instrument 43-101 standards and has reviewed and approved this news release.
About K. Brock Riedell, Consulting Geologist
Mr. Riedell has thirty-nine years of field-based exploration experience for a variety of target types with focus on porphyry Cu-Au-Mo systems, including work with BHP Billiton and Newmont Exploration. He has planned and supervised programs leading to delineation of major porphyry gold and molybdenum deposits in British Columbia, western U.S., Argentina, and Chile. Mr. Riedell recognized open-ended ore northeast of the East zone at Red Chris deposit that led to drilling of hole RC09-350 (647.5 m of 1.50% Cu and 2.68 g/t Au, including 152.5 m of 4.12% Cu and 8.83 g/t Au).
About MDRU
MDRU (Mineral Deposit Research Unit) is one of the most successful integrated mineral deposit and exploration research groups in the world. Founded in 1989, it is a collaborative joint-venture between the minerals industry and the University of British Columbia, focused on solving mineral exploration-related problems and training highly-qualified personnel. MDRU has more than 200 alumni working through the industry and across the globe, and a proven record of accomplishment of delivering successful industry-supported research projects and training.
About the Thorn Project
The wholly owned, 997 square kilometres Thorn Project is located in the Sutlahine River area of northwestern British Columbia, Canada, approximately 90 km …read more
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