The C and E North showing, composed of strongly sheared and altered Upper Triassic greenstones of the Nikolai belt (in part), is developed along the Denali Fault Zone south of Stanley Creek. The meta-volcanics are in fault contact with thin-bedded argillites of the Dezadeash Group to the east. The alteration/shear zone is up to half a kilometre wide and consists of orange to white weathering, fine-grained albite, quartz, and ankeritic carbonates cut by numerous quartz-carbonate veinlets. Sparsely disseminated chalcopyrite occurs along shear planes. Garnierite and chalcopyrite also occur in scattered veinlets. Assay values on selected grab samples ran as high as 4.58 per cent for nickel and 4 per cent for copper (Assessment Report 740).
Carbonate alteration and minor mineralization continue along various strands of the Denali fault zone for several kilometres to the southeast. Mineralization appears to be related to Tertiary movement on the Denali fault.
A 1987 work program is reported to have found float samples which yielded 1.1 per cent nickel, 0.23 per cent cobalt, 0.66 gram per tonne platinum and 0.43 gram per tonne palladium. Soil anomalies have shown values up to 500 parts per million copper, 2,460 parts per million nickel, 260 parts per billion platinum and 910 parts per billion palladium.
Work History
W. M. Erwin staked the area in 1962 to cover three nickel-copper occurrences found in shear zones within quartz-carbonate altered ultrabasic rocks found in a cut bank on the south side of Stanley Creek. Assays of up to 4.6 per cent nickel and 4 per cent copper across 1.2 meters were reported from trenches. A 1500 metre long by 450 metre wide geochemical anomaly, thought to be caused largely by zinc, was outlined to the southeast. A specimen of float about 500 metres downstream yielded 660 parts per billion platinum, 430 parts per billion palladium, 1.1 per cent nickel and 0.23 per cent cobalt.
The property was staked in 1987 by Archer, Cathro & Associates and at this time Dighem Surveys & Processing Inc completed an electromagnetic-resistivity-magnetic airborne survey (Assessment Report 17124). The survey outlined magnetic and EM anomalies on the Mansfield property. Following the geophysical surveys a water pump was used to wash down the face of the showing in Stanley Creek and some trenching was completed over the magnetic anomalies. In 1988 NDU Resources and AAA-X metals (operators) collected 1110 soil samples and excavated 5 trenches in a large claim area. They conducted 72 kilometres of VLF-EM and ground magnetics surveying. It was noted in 1988 that since 1965 the base of the showing had been eroded by Stanley Creek and no evidence of the old trench sites was observed. A channel sample taken across the fault zoned did not duplicate the 1965 data.
In 2000, Santoy Resource collected 289 soil, 37 rock and 4 silt samples. In the vicinity of the C and E South showing where a fetid limestone was apparently the source for anomalous antimony, strontium and lead associated with zinc, soil and rock samples were taken. The soil samples yielded only modestly elevated and sporadic zinc, lead, antimony and strontium value; rock samples yielded only anomalous strontium values (236 to 275 parts per million) (Assessment Report 26556). A rock sample taken in the vicinity of the Stanley Creek Showing (114P 031) (not found) also failed to yield significant results. An excavator trench had been cut at the top of the creek bank along strike but failed to reach bedrock. Neither the unsuccessful trench nor the showings were located during limited exploration in 2000. Soil and rock samples on the whole were reported to have given disappointing results, especially when compared to the previous sampling in 1987.
In 2006, Gerald Diakow prospected his Nickelodium claim which covered the Mansfield (Stanley Creek) and C and E South showing areas. Traverses were made across the property with the intent of locating showings and any old workings. Rock and silt samples were collected. The historical showings were not found, probably because of recent erosion along Stanley Creek. Some of the areas where altered ultramafics were previously mapped were remapped as metamorphic sediments.
