The Whipsaw (South Zone) occurrence is located between Fortyfive and Fortyseven Mile creeks.
A steep-sided, crescent-shaped body of feldspar-quartz-biotite porphyry, 1500 metres long and up to 600 metres wide, intrudes rocks of the Eagle Plutonic Complex and the Nicola Group. A narrow apophysis of the stock extends southeast along the moderately to steeply west-dipping contact between the two units. The Eagle Plutonic Complex consists of foliated biotite granodiorite and granitic gneiss, containing bands of biotite gneiss, biotite amphibole schist and quartzite. The Nicola Group is comprised mostly of amphibole and chlorite schists with lesser quartzite, grit and chloritoid schist. An intrusive breccia, containing clasts of schist or granodiorite in a feldspar porphyry matrix, is occasionally present along the stock's margin. Various dikes and sills of feldspar porphyry, striking north-northwest, intrude the Nicola Group north and south of the stock.
The Nicola Group rocks are altered and extensively pyritized near the stock. Epidote and chlorite are the most common alteration minerals. Argillic alteration is best developed in the margins of the stock. The porphyry also exhibits quartz-sericite alteration, which appears to be associated with the argillic alteration. Feldspars are replaced by kaolinite and minor epidote and sericite in the more altered sections of the stock.
Sulphide mineralization is developed over a widespread area, as disseminations and fracture fillings, and in quartz and calcite veins. Pyrite is most abundant, occurring in quantities of 2 to 10 per cent. The stock contains significant amounts of finely disseminated pyrite when altered. Trace amounts of chalcopyrite, molybdenite, bornite, chalcocite and covellite occur with up to 10 per cent magnetite, primarily in the Nicola Group and Eagle Plutonic Complex rocks flanking the stock, and in the feldspar porphyry dikes and sills. Chalcopyrite is closely associated with pyrite and occurs as disseminations in the porphyry and schist, as fracture fillings, and in quartz-carbonate veins in schist. Molybdenite forms fine-grained coatings along fractures and along margins of quartz and quartz-carbonate veins in the Nicola Group, Eagle Plutonic Complex and feldspar porphyry dikes extending south of the stock. Bornite is closely associated with pyrite and occurs as fine disseminations in the porphyry. Thin blebs and rounded coatings of chalcocite and covellite are present in porphyry dikes to the south.
Stronger mineralization occurs along the stock's northern contact and near the southern contact, where the southeast-trending apophysis extends from the main body. Diamond drilling and trenching has traced a zone of richer copper mineralization in Nicola Group schists, over a distance of 600 metres, along the stock's northern margin.
In 1981, percussion drilling near the southern contact encountered elevated copper and molybdenum values. One hole averaged 0.113 per cent copper and 0.007 per cent molybdenum over 12.2 metres (hole 81-4, 27.4 to 39.6 metres), and a second hole averaged 0.306 per cent copper and 0.0095 per cent molybdenum over 6.1 metres (hole 81-7, 57.9 to 64.0 metres; Assessment Report 9456, pages A-9, A-16). Molybdenum values varied up to 0.068 per cent (Assessment Report 9456, page 3).
In 1991, drilling on the South Porphyry zone, (drill hole 91-1), located within Nicola volcanics near the centre of the concentric-shaped Whipsaw porphyry, returned 58.2 metres grading 0.241 per cent copper; including 5.8 metres of 0.373 per cent copper and 0.018 per cent molybdenum. Another drill hole (91-2), located 170 metres south of drill hole 91-1, returned 99.1 metres grading 0.201 per cent copper (Assessment Report 22147).
In 1995, a drill hole (M95-4) intercepted 0.221 to 0.374 per cent copper over 11.5 metres from Nicola Group rocks near its collar before entering a wide porphyry dike yielding 0.092 to 0.300 per cent copper over 49.2 metres (Assessment Report 24322). This is the first known example of mineralization in dikes or apophyses of the Whipsaw porphyry. In 1997, a lone drill hole (M97-8) was drilled to test the dike further but was terminated short of its design depth due to technical issues. The end of the hole did enter a short section yielding 0.323 per cent copper over 2.9 metres (Assessment Report 25547). The following year, two holes were completed and yielded up to 0.113 per cent copper over 30.6 metres (M98-10) and yielded up to 0.217 per cent copper over 24.2 metres (M98-09; Assessment Report 25836).
The area has been explored in conjunction with the Whipsaw-North Zone (MINFILE 092HSE102) occurrence since its discovery by Texas Gulf Sulfur Company Ltd. in 1959. Various operators, including Texas Gulf, conducted geophysical, geological and soil surveys, trenching and 2572 metres of drilling in 22 holes between 1959 and 1981. The deposit was more recently explored by World Wide Minerals Ltd., with the completion of geological mapping and soil surveys, and 467 metres of drilling in three holes between 1987 and 1993. An additional 22 holes, totalling 2066 metres, were drilled by Phelps Dodge Corporation of Canada Ltd. in 1991. Altogether, 3678 metres of diamond drilling (25 holes) and 1427 metres of percussion drilling (19 holes) was completed between 1961 and 1991. During 1995 through 1998, Martech Industries completed 10 diamond drill holes, totalling 1033.5 metres, on various targets over the Whipsaw property. In 2000, a pulp sampling program was completed to test for platinum group elements from former trenching and drilling programs but results were disappointing. In 2005, Canfleur Mining completed a program of sampling and seven diamond drill holes, totalling 1452.8 metres, on the area. During 2010 through 2015, Martech Industries completed programs of rock and soil sampling.
