Mount Horetzky is located 68 kilometres northeast of Hazelton. The copper-molybdenum showings are located on the southwest side of the mountain at approximately 1460 metres elevation.
The area is underlain by Middle Jurassic to Lower Cretaceous Bowser Lake Group shales, mudstones, sandstones and andesites, which have been hornfelsed by a heterogeneous diorite stock, approximately 2000 by 1000 metres in size, and related plagioclase biotite porphyry dikes ranging in width from 30 centimetres to 15 metres. The dikes are steeply dipping and most strike 135 degrees, some 050 degrees. The intrusive bodies are part of the Eocene Babine Intrusions and have been dated by potassium/argon methods on hornblende at 50 Ma on biotite and 57 Ma (Geological Survey of Canada Open File 2322).
A major zone of mineralization exists adjacent to the hornfels-diorite contact and in associated dikes. Minor hydrothermal alteration is present, with local chloritization of hornblende evident. Pyrite is the most common sulphide and is present in quantities of up to 5 per cent in hornfels, diorite and porphyry dikes (Assessment Report 3870). Chalcopyrite is also found in the intrusive rocks and hornfels, as disseminated grains or in fractures. Molybdenite is rare, occurring in quartz stockworked hornfels with pyrite and chalcopyrite or by itself in dry fractures or in quartz veinlets. The mineralization is best developed in the upper part of the intrusion, within 1 to 60 metres of the roof.
In 2014, a rock sample (Mh-14-14) of heavily fractured diorite (brecciated?) infilled with chalcopyrite near a contact with hornfels assayed greater than 1 per cent copper and 17.5 grams per tonne silver. The vein/fractures are up to 0.5 centimetres wide and contain chalcopyrite-quartz-pyrite. A rock sample (Mh-14-05) of a quartz vein in fractured hornfels analyzed greater than 2000 parts per million molybdenum (upper limit exceeded) (Assessment Report 35659).
Work History
In 1965, Falconbridge Copper Mines staked the original claims and performed a cursory property exam. The claims were dropped the following year and in 1967 Hecla Mining Co. of Canada Ltd. and Pacific Petroleum Ltd. established a large grid and conducted soil sampling, geological mapping and prospecting; this work outlined two copper anomalies. In 1968, Hecla Mining and Pacific Petroleum completed an airborne magnetic and electromagnetic (EM) survey covering 90 square kilometres. The EM survey outlined a number of favourable conductors, some with coincidental magnetic anomalies.
In 1967, Hecla Mining Co. of Canada Ltd. and Pacific Petroleum Ltd. performed soil sampling. One copper-rich area is centred around Station A9 and has a small area of highs up to 0.2 per cent copper, whereas the other copper-rich zone includes most of the south half of the map and contains up to 1 per cent copper and large areas with tenths of a per cent (several hundred parts per million) copper (Assessment Report 01576).
In 1968, MacDonald Consultants Ltd. performed geophysical surveys including electromagnetic and magnetometer measurements in order to map conduction. Several small magnetic anomalies and one main anomaly were found (Assessment Report 01841).
In 1969, Hecla Mining Co. of Canada Ltd. and Pacific Petroleum Ltd. performed line cutting, soil sampling and geophysical surveys on the VAL claims. Results of soil sampling yielded up to 0.0255 per cent copper with no correlation to previous geophysical survey results (Assessment Report 02465).
In 1972, Hecla Mining Co. of Canada Ltd. and Pacific Petroleum Ltd. performed geological mapping, line cutting, a magnetometer survey and an induced polarization survey on the VAL and ADD claims. Anomalous areas were found in both the induced polarization survey and the magnetometer survey, likely corresponding to chalcopyrite mineralization and part of the diorite stock, respectively (Assessment Reports 03870, 03967). In 1973, Hecla Mining Co. performed further induced polarization surveys and designated the major anomalous zone ‘zone A’ with smaller anomalies in zone C and zone D (Assessment Report 04621). Eight diamond drill holes, totalling 1367 metres, were then drilled in 1973 by Hecla Mining Co. with no reported geochemical results, but some visible sulphide mineralization was noted (Assessment Report 04925).
In 1991, Rio Algom Exploration Inc. performed a lake sediment sampling program, which identified anomalous copper values on the KIT claims. In 1992, resampling of drillcore sections, soil sampling over previous lines and sampling of mineralized outcrops was completed by Aglom Exploration Inc. Values from the soil sampling yielded up to 0.4070 per cent copper and one anomalous gold sample of 0.440 gram per tonne gold corresponding with high copper values (Assessment Report 22647). Rock sampling yielded up to 0.2370 per cent copper and weak gold anomalies (sample 15917; Assessment Report 22647).
In the fall of 2013, CJL Enterprises Ltd. assembled a compilation map of historic work completed on the Lone Mountain property which covers the original showing. This information was employed during the 2014 field season to conduct a short program to validate the historic work and to revisit the western slope of Mount Horetzky which contained copper-in-soils anomalies with coincidental magnetic highs. A small north-south soil grid was established consisting of 190 soil samples including 15 rock samples from outcrop. The sampled area was found to contain pyrite, chalcopyrite and molybdenite, though no specific zones of mineralization were found. Pyrite ranges from 0.5 to 5 per cent. A ‘molybdenum zone’ is rich in molybdenite with up to 0.2 per cent molybdenum (sample Mh-14-05)) but poor in copper. Northwest (at 636157 metres east, 6168977 metres north) of the sampled grid, a zone of brecciated diorite infilled with chalcopyrite yielded greater than 1 per cent copper among other significant anomalies, and is likely a new zone of mineralization (sample Mh-14-14; Assessment Report 35659).
