The Marmot Lake occurrence is located approximately 4.6 kilometres northwest of the former Baker mine (094E 026), some 280 kilometres north of Smithers. It lies within the Omineca-Cassiar mountains at the southern end of the Toodoggone old camp. The showing is situated within a Mesozoic volcanic arc assemblage which lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Tertiary sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins.
Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Takla Group andesite flows and pyroclastic rocks. Takla volcanics have been intruded by the granodiorite to quartz monzonite Black Lake Suite of Early Jurassic age and are in turn unconformably overlain by or faulted against Lower Jurassic calcalkaline volcanics of the Toodoggone Formation, Hazelton Group.
The dominant structures in the area are steeply dipping faults which define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high angle northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.
The occurrence area is underlain by andesite crystal tuffs, volcaniclastic breccias and hypabyssal quartz trachyandesites, part of a larger package of Toodoggone Formation volcanics assigned to the Metsantan Member and dacitic volcanic rocks of the Saunders Member. Other lithologies of the Metsantan Member include mostly latite lava flows with interflow lahar, and a mix of epiclastic and pyroclastic rocks (Bulletin 86).
Several major structures are observed disrupting the moderately dipping interbedded crystal tuffs and volcanic rocks underlying the occurrence. These structures are the southward extensions of major faults related to epithermal mineralization at the Silver Pond prospects (094E 069, 75 and 160-163) and the Lawyers mine (094E 066).
Mineralization at the Marmot Lake showing consists of disseminated pyrite with lesser chalcopyrite, galena and sphalerite in quartz veinlets within Toodoggone crystal ash tuffs.
Another zone of mineralization, referred to as the Marmot Lake East zone, is located approximately 500 metres east of the main Marmot Lake occurrence and comprises sulphosalt-bearing mineralization, silicification and potassic-alteration along north-northwest–trending faults.
Later work, circa 2019 and 2020, indicated that mineralization is associated with moderate to strong propylitic or potassic alteration, epidote veining and increased epidote and sericite in groundmass and is related to structure. The alteration zones are fault bounded with mineralization occurring proximal to fault gouge and breccias. Higher-grade intervals/zones are correlated with millimetre-scale metallic grey sulphide veinlets and quartz/chalcedony veins.
Work History
During 1971 through 1973, Kennco Explorations completed programs of geochemical (rock, silt and soil) sampling, prospecting and geological mapping on the area as part of the Lawyer property. In 1971, a rock sample (S34724) from an area of green porphyry hosting pyrite assayed 0.16 gram per tonne gold and 34.5 grams per tonne silver (Assessment Report 3416). Further sampling was completed the following year and identified zones of anomalous gold and silver values associated with facture zones trending 000, 040 and 325 degrees (Assessment Report 3837).
The Law 1, 2 and 3 claims were staked in 1978 by S.E.R.E.M. Ltd. (Serem). In part, this ground covers the old Lawyers claims on which Kennco Exploration mapped and conducted soil and rock geochemical surveys. The Serem work extended the Kennco geochemical coverage to the east and south on Law 1 and 2 and to the northwest on Law 3. Work done this done (1978 or 1979) consisted of soil surveys on all three claims. A total of 890 samples were collected, half these on the Law 3 claims and half on Law 1 and 2.
In 1980, Work done by Serem included two soil grids on the Law 1 claim. A total of 506 samples were collected over an area of 0.54 square kilometers. Also, at this time a ground magnetic survey was completed on the nearby Attorney claims by SEREM.
In 2007, Christopher James Gold Corp took 59 rock samples from an area hand trenched and drilled in the 1960 to early 1970s. Mineralization in the Marmot Lake trenches consists of pyrite, tetrahedrite, chalcocite, chalcopyrite and malachite within an argillic and carbonate altered zone surrounding a silicified hydrothermal breccia. Mineralized quartz stringer in silicified andesite breccia. Sampling of the historically trenched area yielded assay values of 50.6 grams per tonne gold and 24.8 grams per tonne silver over 0.7 metre in chip sample MA-08, located between the northernmost two trenches; a grab sample (MA-05) from the northernmost trench yielded 8.88 grams per tonne gold and greater than 100 grams per tonne silver, and another grab sample (GR9), taken north of the trenches, assayed 12.3 grams per tonne gold and greater than 100 grams per tonne silver (Assessment Report 29529). Also at this time, a 1- by 1-metre panel sample (MA-22) from the southernmost trench assayed 0.67 gram per tonne gold, 31 grams per tonne silver, 0.718 per cent copper, 0.027 per cent molybdenum, 0.697 per cent zinc and greater than 1.00 per cent lead (Assessment Report 29529).
In 2018, Benchmark Metals Inc. and PPM completed a program of geochemical (rock and soil) and biogeochemical sampling, a 1272 line-kilometre airborne radiometric survey, eight diamond drill holes, totalling 1493.0 metres, and 30 rotary drill holes, totalling 2623.0 metres. This work focused along the Layers mineralization trend, which is greater than 3 kilometres in length.
Two rock samples (575611 and Y445364) from the Marmot zone yielded 31.8 and 61.3 grams per tonne gold with 1590 and 3890 grams per tonne silver, respectively (Assessment Report 38447). An outcrop sample (Y445202) of oxidized feldspar andesite-dacite(?) hosting quartz veinlets with disseminated pyrite and a fine-grained dark sooty sulphide (acanthite?), taken approximately 450 metres to the southwest of the Marmot zone assayed 4.97 grams per tonne gold and 872 grams per tonne silver, whereas a subcrop sample (Y445206) of feldspar phyric tuff(?) with silica veinlets and weak limonite staining, located approximately 250 metres southeast of the Marmot zone, assayed 2.31 grams per tonne gold and 99 grams per tonne silver (Assessment Report 38447). An undescribed rock sample (Y445046), taken approximately between the previous two samples, yielded 23.1 grams per tonne gold and 67.4 grams per tonne silver (Assessment Report 38447). Also at this time, two other rock samples (Y445284 and Y445287), taken from the west side of a northeast-trending ridge located approximately 1.5 kilometres to the north-northeast, yielded 0.163 and 0.132 gram per tonne gold with up to 12.65 grams per tonne silver (Assessment Report 38447). No descriptions were provided for the latter two samples.
In 2019 and 2020, Benchmark Metals Inc. completed programs of geochemical (rock and soil) and biogeochemical sampling, ground and airborne geophysical surveys, 242 diamond drill holes, totalling 69 080 metres, and 191 reverse-circulation drill holes, totalling 28 395 metres, on the area as part of the Lawyers property. The majority of the drilling targeted the Cliff Creek, Dukes Ridge, Phoenix and AGB zones of the Lawyers (MINFILE 094E 066) deposit but five holes, totalling 1434 metres, were completed on the Marmot Lake occurrence.
During this time, rock grab samples from the Marmot Lake area are reported to have yielded up to 61.3 grams per tonne gold and 3890 grams per tonne silver, whereas five samples from the Marmot Lake East zone yielded from 3.63 to 24.2 grams per tonne gold and 129 to 1425 grams per tonne silver (P&E Mining Consultants Inc. [2021-06-28]: Technical Report and Updated Mineral Resource Estimate of the Lawyers Gold-Silver Property, Omineca Mining Division, British Columbia, Canada).
In 2020, drilling on the Marmot Lake zone yielded intercepts of up to 0.55 gram per tonne gold and 21.8 grams per tonne silver over 101 metres, including 9.83 grams per tonne gold and 375.0 grams per tonne silver over 2 metres in hole 20MLDD005 (P&E Mining Consultants Inc. [2021-06-28]: Technical Report and Updated Mineral Resource Estimate of the Lawyers Gold-Silver Property, Omineca Mining Division, British Columbia, Canada).
See Lawyers (094E 066) for further details of related work history.
