The TK 81 (U zone) is located on a north-northeast–facing slope, approximately 5 kilometres west of the Frog River and 19 kilometres north of the confluence of the Frog River with Geese Creek.

Regionally, the area lies on the western edge of the Omineca Belt near the Kutcho fault, marking the boundary with rocks of the Intermontane Belt. The area is underlain by Early Jurassic granodioritic intrusive rocks of the Pitman Batholith with minor roof pendants of metavolcanic and metasedimentary rocks. Early regional mapping correlated these rocks with the Devonian to Permian Asitka Group based on lithological similarities (Geological Survey of Canada Open File 483). Fossil evidence from later regional mapping dates least part of the sequence as Mississippian (Geological Survey of Canada Paper 80-1B, pages 207-211). A tentative age of Devonian to Permian is given to these metamorphic rocks.

Five stratigraphic units have been recognized and are, from oldest to youngest, feldspathic chlorite schist; phyllite, sericite and calcareous sericite schist; massive rhyolite, chert and sericite schist; carbonate and an upper feldspathic chlorite schist. The rocks are complexly folded and have undergone at least two phases of deformation. They are predominantly calc-alkaline with minor alkaline members. The sequence is similar in many respects to rocks of the Kutcho Formation in the southeastern corner of the Cry Lake map area (NTS 104I).

Locally, several molybdenite occurrences are found in metamorphic rocks composed of quartzite, and chlorite, sericite and biotite schists. Inclination of the metamorphic-intrusive contact decreases from vertical in the west, near the TK 81 occurrence, to 30 degrees south in the east. Schistosity is parallel to the attitude of the contact. Evidence suggests that the metamorphic rocks were intruded by the granite to granodiorite pluton, which at the TK 81 occurrence are massive, poorly fractured, blocky and frequently host pegmatitic dikes . The pegmatite dikes are up to 60 centimetres wide and are composed of feldspar, quartz, biotite, muscovite and magnetite. Some pegmatites contain crystals up to 5 centimetres . Fractures in the granite and granodiorite have been infilled with finer grained compositional equivalents.

The TK 81 (U zone) occurrence consists of several molybdenum-copper occurrences near the metamorphic-granite contact in a biotite monzonite gneiss. Molybdenite occurs as blebs and sheets parallel to planes of schistosity, replacement of mafic minerals in granite, and blebs and scales in widely spaced fault zones. A sericite schist unit contains the majority of the molybdenite, whereas granites contains sparse molybdenite blebs up to 0.6 centimetre in diameter. The main occurrence, referred to as the U zone, covers an area 23 metres long by 0.6 to 9 metres wide. In the immediate area of the U zone quartz veins associated with an altered granite host pyrite, chalcopyrite, chrysocolla, molybdenite and magnetite with minor to trace bornite, malachite, azurite and sphalerite mineralization.

At least two other minor molybdenite occurrences, referred to as the T and S zone and associated with two fault zones cutting across granite and schists, are located approximately 400 and 800 metres southeast of the main zone on the former TK 81 and TK 84 claims, respectively.

Another zone of minor copper mineralization, referred to as the L zone, is located approximately 800 metres east-southeast of the main (U) zone on the former TK 85 claim and comprises a 10-centimetre wide quartz vein with minor chalcopyrite and bornite mineralization.

In 1967, it was reported that the best grade from the U zone may run up to 1 per cent molybdenite, whereas a sample from a ‘high-grade’ zone, 3.6 metres high by several inches wide, from the T zone was estimated to contain 2 per cent molybdenite (Assessment Report 1674). Also at this time, a sample (44723) assayed 0.7 gram per tonne gold, 23.9 grams per tonne silver, 0.59 per cent copper and 0.01 per cent molybdenum (Property File - Cordilleran Exploration Corp. Ltd. [1968-02-01]: Report - 1967-69 Toodoggone).

In 2011, a sample (4117) from a 0.3- to 0.6-metre wide quartz vein assayed 0.013 per cent molybdenum; a sample (4119) with pyrite, molybdenite and chalcopyrite yielded 0.028 per cent molybdenum and 0.186 per cent copper; sample (4125) of quartz blebs hosting pyrite, chalcopyrite and magnetite with trace bornite and sphalerite yielded 0.510 per cent copper and a sample (4127) of altered granite with pyrite assayed 0.10 gram per tonne gold and 0.129 per cent copper (Assessment Report 32631). The samples appear to have been collected from the area of and/or between the U and T zones.

In 2012, samples (129063 and 129065) from the U-T zone area assayed up to 0.563 per cent copper and 0.409 per cent molybdenum, whereas samples (129012 and 129088) from the S zone area yielded 0.468 per cent copper and 0.225 per cent molybdenum (Assessment Report 33391). Also at this time, two samples (129709 and 129710) from a large boulder in the L zone area yielded 4.0 and 2.3 grams per tonne gold and 23.3 and 55.1 grams per tonne silver with 1.34 and 3.49 per cent copper (Assessment Report 33391).

Work History

In 1967 and 1968, Quebec Cartier Mining Co. completed programs of geological mapping and silt sampling on the area as the TK 1-88 claim block.

In 2007, Charles Greig staked the area as the Pit Bullfrog property. In 2008, Bitterroot Resources Ltd. optioned the property and executed a program of stream sediment and moss mat sampling on the area.

In 2011, International Samuel Exploration Corp. optioned the Frog property and completed a program of prospecting, rock sampling and a 1029.0 line-kilometre airborne magnetic geophysical survey. The following year, a program of prospecting, talus slope sampling, detailed petrological analysis of outcrop and subcrop mineralization and fluid inclusion studies was completed.

In 2014, CJL Enterprises completed a program of geochemical and geophysical data review and rock sampling. The following year, a program of mineralographic and petrographic sampling was completed. In 2017, a total of 158.0 line-kilometres of airborne magnetic surveying was completed on the area as the Frog South and North properties. The following year, a program of 3-D magnetic modelling was performed on the previous year’s geophysical data.