The Coquigold gold project was initiated late in 2018 in response to the discovery of a significant epithermal gold system by Westhaven Ventures Inc. at Shovelnose Mountain adjacent to the Coquihalla Highway, 30 kilometers south of Merritt, BC. Two claim blocks were staked to cover epithermal occurrences discovered by the British Columbia Geological Survey in 2008 and published in a subsequent open file report. The Red Vein Target covers a silica altered intrusive/volcanic breccia which is strongly anomalous in several epithermal pathfinder elements and silver. The Sinter Target covers a 500 meter long silica sinter and silica exhalite which is also anomalous in an epithermal suite of elements.
Red Vein Target
The Red Vein claims cover an area (the D Zone) where a sample of silica altered volcanic? was sampled in 2008 by the British Columbia Geological Survey and published in paper 2008-8. The sample was a composite chip from outcrop and subcrop over an area with a width of approximately 20 meters (before disappearing under overburden). It is described as a red oxidized silica altered volcanic containing minor bladed barite in a siliceous gangue. The sample returned 2,423 ppb silver (2.4 g/t), 173 ppm arsenic, 4,250 ppb mercury, 23 ppm antimony, 794 ppm lead, 623 ppm copper and <0.2 ppb gold.
Subsequent collection and analysis of several samples in 2019 by Cariboo Rose from the alteration zone included silver values to 43.1 ppm (43.1 g/t), arsenic to 559 ppm, mercury to 13.4 ppm (13,400 ppb), antimony to 101 ppm, lead to 2,593 ppm, copper to 933 ppm and gold to 2.0 ppb. Host rocks are interpreted to be dominantly brecciated quartz diorite with a possible minor component of volcanic rock. Alteration consists of pervasive chalcedonic quartz flooding, limonite/hematite/pyrite gossan on fractures with occasional malachite. The zone is attenuated in a north south direction and extends to the northern boundary of the claim (its continuation further northward is unknown). The present dimension of D Zone is approximately 40 meters by 100 meters with the zone disappearing beneath overburden to the west and northeast. Local limonite alteration zones in the quartz diorite occur on this same trend for 1,200 meters south suggesting a fault along this trend.
No evidence has been found of any additional sampling of this occurrence since its discovery in 2008 and staking by Cariboo Rose in 2018.
A second zone of alteration discovered and described by the BC Geological Survey in 2008 occurs 2.8 kilometers to the northwest of D Zone. This Zone, called the XYZ Zone is an area of bedded siliceous rocks (sinter) located within outcrops of porphyritic basalt rocks. An old trench and pit are located nearby (no MINFILE reference exists). Grab samples from the old workings returned anomalous values; copper to 792 ppm, zinc to 815 ppm, arsenic to 334 ppm and gold to 30.8 ppb.
Historic mapping identifying Eocene aged rocks on the west side of the claim block suggests the claims are situated on the eastern edge of the Eocene aged Fig Lake Graben, a narrow north-south trending feature related to the Coldwater Fault system (Thorkelson, Geological Survey of Canada, 1985 and 1989).
The discovery of at least three areas of hydrothermal silica (the D, XYZ and Castilian zones) on a graben edge warrants carefully continuing to explore areas in between (prospecting, soils and silt samples). Deeper or shallower paleo-elevations could host economic concentrations of gold and or silver. Further exploration of these targets is being planned.
The Sinter claims cover a silica sinter-exhalative occurrence discovered and described by the British Columbia Geological Survey in 2008 (open file 2008-8) with additional information published in 2016 (BCGS Paper 2016-1). The silica occurrences at the Sinter claims are described by The BC Geological Survey as follows: “A new occurrence characterized by stratified and strataform silica carbonate horizons, has been discovered within shallow–marine stratified volcanic and sedimentary rocks of the Late Triassic Nicola Group. Named the Castillian Creek Exhalite-Sinter, they have weakly anomalous signature for the epithermal suite of elements”. The sinter consists of several stacked layers extending for approximately 500 meters along strike through a vertical elevation range of approximately 100 meters (strike north northeast, dip 20-30º southeast). The sinter is exposed along strike for approximately 300 meters. The exhalite and sinter exposures appear to be interbedded with Nicola Group volcanic rocks. No evidence has been found of any additional sampling of this occurrence since its discovery in 2008 and subsequent staking by Cariboo Rose in 2018.
Mapping by the BC Geological Survey has interpreted the Castillian Creek Exhalite-Sinter to be Triassic age based on an age date of 224 Ma (Upper Triassic) of interbedded rhyolite tuff. An alternate explanation for the origin of the sinter/exhalite would be that it is younger than the interbedded Nicola rocks with the hydrothermal fluids having exploited porous stratigraphic horizons.
An optimistic analogue of a deposit style associated with a weakly mineralized to unmineralized sinter is the Fruta Del Norte deposit in Equator. Fruta Del Norte is a high-grade epithermal deposit discovered in 2006 that is currently being put into production by Lundin Gold Inc (5.02 million ounces gold @ 8.74 g/t). It is hosted in Jurassic andesitic to basaltic volcanic rocks and was a blind discovery. The sinter at Fruta Del Norte is anomalous in arsenic, antimony and mercury and very weakly anomalous in gold and silver. It sits stratigraphically on top of the deposit and is itself covered by unmineralized conglomerate and sandstone which infilled the graben.
The area to the south of the highway is considered more opportune because of better access away from the Coquihalla Highway (from the Comstock exit). A logical next step would be to establish a north-south oriented soil grid in this area.
The Lower Exhalite, located on the north side of the Coquihalla Highway, also warrants further examination because of its promising description by The BC Geological Survey (chalcedony, chert, jasper and interbedded carbonate including a sample described as being banded chalcedonic carbonate rock cut by a fracture containing chalcopyrite, exposed in a very old trench).