The Todd Creek (South zone) prospect is located at the headwaters of Todd Creek, immediately north of the toe of Todd Glacier, 35 kilometres northeast of Stewart.
The area is underlain by Hazelton Group rocks of the Lower Jurassic Unuk River Formation. The mineralized zone occurs in feldspar porphyry (flows?, intrusion?) which is exposed over an area 950 by 500 metres. The porphyry is bound to the west and north by dark green-grey andesite flows and agglomerates and to the south and east by glacial till. The western contact is not exposed. The northern contact is defined by a north trending, east-dipping fault. The feldspar porphyry is pervasively altered and most of its western portion exhibits quartz-pyrite alteration. Further east, near the mineralization, quartz-sericite alteration prevails over locally developed chloritic and iron carbonate alteration.
Mineralization on surface comprises chalcopyrite, pyrite, specular hematite and malachite. The mineralization is hosted in a 5 to 15 metre wide north-northeast trending, steeply west dipping fracture zone that cuts the eastern portion of the exposed porphyry. The mineralization occurs along the southern 425 metres and the northern 100 metres of the exposed zone (Assessment Report 18800). The fracture zone is transected by several east striking post-mineralization faults that exhibit both minor dextral and sinistral displacement.
In the fracture zone there are two types of mineralization: a) massive pyrite-chalcopyrite stringers and veins, 1 to 10 centimetres wide and b) a zone of quartz-hematite-chalcopyrite stringers and breccia veins up to 3 metres wide. The sulphide veins generally exhibit higher molybdenum, copper and arsenic values than the breccia veins. Typically, the mineralized fracture zone comprises 1 or 2 large quartz breccia veins, separated by a stockwork of narrow quartz-hematite veins. The larger breccia veins generally occur along the footwall and hangingwall of the zone.
In 1987, a channel sample taken from trench 13 assayed up to 4.35 grams per tonne gold across 1.9 metres. The 1987 drilling program resulted in a sample which assayed up to 6.85 grams per tonne gold and 0.23 per cent copper across 6.15 metres (hole NTC-87-9) (Assessment Report 17423).
The 1988 drilling tested the downdip continuity of the zone in holes NTC-87-2 to 9 and the northward continuity of the higher-grade mineralization encountered in NTC-87-9. The best intersection assayed 3.61 grams per tonne gold and 0.27 per cent copper across 29.75 metres in hole NTC-88-19; this included 6.91 grams per tonne gold and 0.36 per cent copper across 8.15 metres (Assessment Report 18800).
The Todd Creek (South zone) is reported to contain inferred geological reserves of 207,000 tonnes grading 5.48 grams per tonne gold (Hemlo Gold Mines Inc. Annual Report, 1988).
Island-Arc Resources Corp. optioned the property in 1997. Work consisted of geological mapping, rock and soil sampling of the North zones (104A 105, 106) and Fall Creek zone (104A 107), re-logging and resampling of drill core from 1986-87 Noranda drilling at the South zone. From the preliminary work it appears the mineralized zones are all part of a larger epithermal gold system striking north to south through the length of the property. The system defined to date is seven kilometres long, up to 1.5 kilometres wide and has a 1.1 kilometre vertical extent. It consists of multiple quartz veins with sulphide, hematite and carbonate minerals commonly associated with a quartz-sericite-pyrite alteration assemblage. Individual zones exhibit classic epithermal features with thinly banded veins, open space and colloform veins, and vein breccia; the latter suggesting multiple mineralizing pulses.
The metal assemblage of the mineralized zones defined to date seems to further reflect an epithermal system with both vertical and horizontal zonation features. Starting from the south at the lowest elevation, the South zone is characterized by deeper and higher temperature gold-copper mineralization. To the north, the North zone, Fall Creek zone, and Ice Creek zones (104A 108) contain multiple veins with gold mineralization occurring with high copper, but also with increasing lead and silver at some of the higher elevations. This is the widest portion of the system defined to date. The highest and most northerly zone is the Amarillo zone (104A 104) in which strongly altered volcanics occur over a two square kilometre area about 1.5 kilometres north and up to 900 metres above the North zone. Here, upper level hot springs-type of mineralization is found consisting of quartz barite veins and stockworks containing high levels of mercury and antimony (George Cross News Letter No.150 (August 6), 1997).
However, based on 2006 studies and the results of a 2007 exploration program, such apparent epithermal mineralization referenced above are now postulated to be the near-surface expression of more substantial gold-copper porphyry and/or exhalative mineralizing systems at depth. For example, the South zone deposit and its along strike extensions (MEXT, NEXT zones) are thought to be feeder zones (SZ Feeder zone), possibly associated with a volcanogenic massive sulphide system at depth; or, a gold-copper porphyry system related to an intrusion, such that the intrusion, the resulting deformation, the formation of the structurally hosted, gold-copper multiphase breccia veins and mineralogical and alteration zoning are closely related spatially, temporally and genetically. It is also contemplated that one or more such porphyry and/or exhalative systems are also associated with the expansive sulphidized environments of the Yellow Bowl zone (104A 111) and of the OMTA (Orange Mountain Target Area) zone (104A 104).
In 1959, the South zone copper-gold epithermal mineralization was discovered by Newmont Mining Corporation and evaluated via trenching and five drillholes totalling 350 metres. In 1969, W. Christians staked the Todd 1-6 claims over the occurrence for Kerr-Addison Mines; no work was reported. In 1971, A.G. Hodgson conducted a geological examination. From 1981 to 1984, Woodcock and Riocanex conducted extensive geological and geochemical programs on their claims on and in the vicinity of Orange Mountain. The next significant work on the South zone was carried out by Noranda who staked the Toc 1-12 claims in 1986 and 1987 and completed mapping, trenching, sampling and the drilling of 57 holes (5225.5 metres; 1987, 1988, 1990). The drilling outlined a non-compliant National Instrument 43-101 historical reserve of 207,000 tonnes grading 5.48 grams per tonne gold (Hemlo Gold Mines Inc., 1988 Annual Report). The deposit was outlined over a strike length of about 375 metres and to a vertical depth of about 150 metres. Golden Nevada Resources Inc. entered into a joint venture with Noranda to earn 50 per cent in 1987. In 1989, ownership of the Toc claims was Goldnev Resources (50 per cent), Noranda Inc. (13.9 per cent), Brenda Mines Ltd. (13.9 per cent) and Hemlo Gold Mines Inc. (13.9 per cent). The Noranda work and that with joint venture partner Golden Nevada Resources also discovered numerous showings and zones; the most significant mineralization was located on the North A zone (104A 106) where drill intersections ranged up to 3.47 grams per tonne gold and 0.75 per cent copper over 31.85 metres; and, the Fall Creek East zone (104A 107) where drill results ranged up to 3.94 grams per tonne gold over 7.9 metres.
In 1994, Oracle Minerals Ltd. funded an exploration program which included data compilations, geological and geochemical surveys on the Fall Creek North and Amarillo zones, along with an Aerodat airborne conventional electromagnetic, magnetic and radiometric survey. Based on the work, which confirmed the importance of several historical copper-gold and lead-zinc-silver showings and located others, a 1997 follow-up program was recommended that included an 1800 metre drill program. In view of the adverse investment climate, Oracle did not to carry out the work. In 1997, under an option agreement with Island-Arc Resources Ltd., Geofine Exploration Consultants Ltd. carried out a program that comprised the staking of 5 additional claims, an examination of the historical South zone core from which 47 check samples were obtained. Geological and geochemical surveys (953 samples) were carried out on the Amarillo, North A, South and Yellow Bowl (104A 111) zones and reconnaissance surveys on the East Target Area and the Mylonite zone.
In 1999, Okak Bay Resources Ltd. optioned the property from Geofine and funded an exploration program where the work included the discovery of the Zn, MEXT and NEXT zones, in which auriferous specular hematite is a significant component of the mineralization. The MEXT and NEXT zones represent the along strike, northern extension of the South zone. Detailed geological and geochemical surveys were carried out on the North A, Fall Creek (104A 107) and the Amarillo zones. The historic Noranda drillholes on the South zone were located and tied into a new baseline. Fourteen proposed drillholes were spotted on the South zone, NEXT, North and Amarillo zones, and a drill program comprising at least 1200 metres was recommended.
In 2000, Island Arc Mining Corporation funded a geological and geochemical program to mainly evaluate the apparent northern extension of the South zone deposit. The work was carried out by Geofine and included the staking of the Benji 8-12 claims to cover the postulated southern and northern extensions of the South zone; the taking and interpretation of helicopter air photos of the South zone to precisely locate the “South Zone Structure” and its possible extensions; the refurbishing of parts of the historic Noranda/Geofine South zone grid and the re-spotting of the drillholes located in 1999 on the South zone; and, the carrying out of geological and geochemical surveys on control lines at the South zone and the Knob zone (104A 109). The program also included the refurbishing of part of the Amarillo grid and re-spotting of drillholes spotted in 1999, as snow conditions allowed. Some detailed grid lines were also installed over the Barite and North Barite zones. A total of 368 rock, soil, stream sediment and check samples were collected and analyzed; three trenches were excavated totalling 150 metres. It was concluded that the Knob zone, located 3 kilometres north of the South zone deposit, is one of the most important exploration targets on the property; the large Amarillo epithermal system, located 2.5 kilometres northwest of the Knob zone, may have the largest tonnage potential for a polymetallic deposit on the property, including Eskay Creek-type volcanogenic massive sulphide mineralization; and, the Yellow Bowl zone (104A 111) has potential for gold-copper porphyry mineralization.
In 2003, Lateegra Resources Corporation entered into an option agreement with Geofine Exploration Consultants Ltd. whereby Lateegra may acquire a 100 per cent interest in the Todd Creek property. In 2004, Lateegra Resources Corp. optioned the property from Geofund and funded an exploration program carried out by Geofine. The work included grid restoration, topographic surveys, drillhole spotting, camp installation, diamond drilling, core logging and sampling, the collection of three large composite samples of mineralized talus and reclamation. The six confirmation and step-out drillholes on the South zone deposit and the NEXT zone totalled 761 metres.
In 2004, Lateegra tested the South zone, with five drillholes. Drillhole SZ04-04 intersected 1.25 metres grading 8.55 grams per tonne gold and 0.67 per cent copper (Exploration and Mining in British Columbia 2004, page 32). Step-out drilling intersected the gold-bearing vein 500 metres north of previous drilling.
In 2005, under the terms of an option agreement, Goldeye Explorations Ltd. optioned the Todd Creek Property from Geofund and Goldeye and Polar Star Mining Corporation funded an exploration program in 2006 that was carried out by Geofine and included grid restoration (~3 kilometres), location of historic drill collars, topographic surveys, hole spotting, camp installation, diamond drilling (1330 metres in 8 holes on the MEXT, East Fall Creek and North A zones), core logging and sampling, reclamation and a MMI-M orientation soil geochemistry survey (11 sample sites, 44 samples) on the Amarillo grid of the Orange Mountain Target Area. Based on the results of the 2006 program it was concluded that the South zone mineralization has been traced for over one kilometre and remains open at depth and along strike to the south and the north.
The 2007 field program was funded by the Goldeye/Polar Star Joint Venture and totalled about $1.766 million. The work was carried out by Geofine and included interpretation of the historic Geonex Aerodat 1994 airborne survey and a general compilation of geophysical data and mineral showings; snow cat plowing and construction of the exploration camp; grid installation and restoration (South Grid, Orange Mountain Target Area and the MEXT-NEXT Grid on the South zone) with about 22 kilometres of geophysical grid; helicopter-acquired air photos and structural interpretations; GPS surveying of historic drill collars; geological and geochemical surveys; geophysical surveys (~18 kilometres of magnetics, VLF-EM and Spectral induced polarization); about 3600 metres of borehole induced polarization; drillhole spotting, topographic and GPS surveys; diamond drilling (2818.02 metres in 12 holes on the South zone grid, South grid, and Amarillo grid, Orange Mountain Target Area (OMTA); core logging and sampling; thin section studies; and reclamation.
In 2008, Intuitive Exploration Inc. optioned the tenures from Polar Star Mining Corporation and Goldeye Explorations Limited. The 2008 field program on behalf of Intuitive Exploration included geological and geochemical surveys (1081 rock, check and re-run samples), 23 stream sediment samples, mass spectrometer scans (261 samples) and, diamond drilling (2585.62 metres in 8 holes) and additional sampling of core from two 2007 holes (a total of 1920 core and check samples). No field work was carried out in 2009.
In 2010, the Todd Creek Joint Venture was formed after Intuitive Exploration Inc. exercised its right to earn a 51 per cent ownership interest in the Todd tenures. Polar Star Mining Corporation and Goldeye Explorations Limited together have the remaining 49 per cent ownership interest. With the merger of Intuitive Exploration Inc and Orestone Mining Corp in 2010, Orestone became the operator of the Todd Creek Joint Venture. In the same year, an exploration program on the property comprised a helicopter-borne geophysical survey using a versatile time-domain electromagnetic (VTEM) system with Z component measurements and aeromagnetic survey using a cesium magnetometer. The survey totalled 2203.3 line kilometres of geophysical data acquired. The original 2203.3 line kilometre survey was partially reflown with a 581.3 kilometre survey on a Test Block due to difficulties encountered with the rugged topography. The processed data identified 18 Volcanic Massive Sulphide (VMS), 10 mesothermal and 7 porphyry type target zones.
In 2016, Millrock Resources Inc. conducted a program that consisted of magnetic susceptibility (MS) studies on several historic drill holes and numerous compilations Assessment Report 36183). A total of 1416 MS readings and hand magnet readings were taken on core from drill holes DDHTC08-06, DDHFC06-01A on the Knob and Fall Creek East Zones, respectively, on the Todd Tenures; and, from DDHP06-04 drilled on the X zone (Upper Grid) of the Poly prospect (104A 177).
A total of 14 rock samples were collected in 2016 and 8 were submitted for analysis. Individual results range from 77 grams per tonne silver, 0.73 per cent copper, 6.24 per cent zinc from the VMS Zone (104A 185) to 9.58 grams per tonne gold and 3.68 per cent copper at the North A Zone at Fall Creek (104A 107); and, to 375 grams per tonne silver, and 0.15 per cent zinc at the Waterfall Zone (104A 102) (Assessment Report 36183).
In 2017, Millrock Resources Inc. collected total of 238 stream sediment samples from an area measuring 6 by 16 kilometres (Assessment Report 37268). Multielement anomalies were found to occur in areas of known base and precious metal mineralization which extend for 10 kilometres along the Todd Creek valley. Geochemical data was generated from drainages that hosted the following MINFILE occurrences: 104A 103 (Bow 31), 104A 104 (Woodcock), 104A 106 (Todd Creek (North Zone)), 104A 107 (Fall Creek), 104A 108 (Ice Creek), 104A 109 (Knob 1), 104A 110 (Ridge), 104A 111 (Yellow Bowl), 104A 154 (Knob 2), 104A 181 (SCK) and 104A 183 (Virginia). Results also indicated a 1.5 kilometre in diametre area around the Falls Creek, Orange Mountain and Yellow Bowl occurrences that were anomalous in gold, silver, copper, lead and zinc. Pathfinder elements of cadmium, barium, phosphorous and antimony were strong, and tellurium, was particularly anomalous in seven samples collected in a one-kilometre-diametre area.
Two new geochemically anomalous areas called named Surveyor and MJ also resulted from the 2017 program. Coincident VTEM, magnetics and multielement stream sediment anomalies characterize the Surveyor prospect which is located at UTM 459350 metres east, 6240050 metres north. The Surveyor area is anomalous in gold, silver, copper, molybdenum, lead, zinc, and pathfinder elements cadmium, antimony, tungsten, sulphur and phosphorous. Of note is strong nickel anomaly. The second new area of interest identified by the stream sediment program is named MJ and is anomalous in gold, copper, molybdenum, lead, zinc, and pathfinder elements barium, germanium, tellurium, tungsten, uranium and niobium. Previous geophysical surveys indicated possible porphyry-style mineralization. The MJ is located at UTM 449200 metres east, 6230650 metres north.
In 2018, Millrock announced that three exploration projects in the Golden Triangle District - Oweegee Dome, Willoughby and Todd Creek - have been sold to Sojourn Exploration Inc.