The Late occurrence is located on the east side of Schaft Creek approximately 55 kilometres upstream from the confluence with the Stikine River.
The showing is located along the eastern margin of the Middle Jurassic Yehiniko pluton. The pluton is comprised of a distinctive tan to orange weathering, salmon pink, hornblende-biotite granite to quartz monzonite and lies in the middle of the north trending Jurassic-Triassic Hickman batholith. To the east of the pluton lies a thick succession of Upper Triassic volcanic rocks of the Stuhini Group. The package consists of well-bedded volcanic greywackes, lapilli tuffs and volcanic breccias that are overlain by more massive, often pyroxene porphyritic andesitic to basaltic flows. Regional bedding attitudes strike north and dip moderately to the east although local variations due to folding are common.
It should be noted that in 2015, Teck Resources reported that the intrusive rocks in the "Greater Kopper" area (roughly equivalent to the Arc (104G 078) and Late (104G 063) area), though having been mapped as part of the Early Jurassic Yehinkio Pluton, are interpreted by them (Teck) as Late Triassic granodiorite to quartz monzodiorite, similar to the Hickman Pluton further south.
The intrusive-volcanic contact is characterized by an 80 metre thick metasomatized zone within the volcanics. The volcanics have been recrystallized and locally the contact is hornfelsed or altered to chloritic schist.
Alteration which includes feldspathization, sericitization and chloritization occurs in all units adjacent to the numerous east trending faults and shears. Sparse mineralization occurs throughout the adjacent areas, but it is most prominent along the intrusive-volcanic contact and in shear/alteration zones. Within the volcanics and metasomatized contact zone are irregularly distributed fine specks of chalcopyrite and bornite. Two, three-kilogram chip samples collected over 25 metres averaged 0.07 per cent copper and 0.2 gram per tonne gold (Assessment Report 9660).
Two types of mineralization occur within the intrusive rocks: 1) Disseminated to small, massive clots of pyrite, chalcopyrite and bornite occur in narrow discontinuous widely distributed quartz veinlets. 2) Pyrite, chalcopyrite and bornite are found along silicified fractures adjacent to shear zones. This type of mineralization seldom exceeds 10 metres in width and fades vertically. Chip samples collected over 5 metres along the length of two adjacent shears contained 0.16 and 0.05 per cent copper, with negligible molybdenum, silver and gold (Assessment Report 9660).
A 3 metre long trench sample from Grizzly Creek area at 1664 metres elevation contained 0.38 per cent copper (Assessment Report 3985). This elevation on Grizzly Creek would place it in the vicinity of the Late occurrence. Most samples were below 0.5 per cent copper.
In 2015, a quartz monzonite rock sample taken a few hundred metres south-southwest of the Late showing's MINFILE plot assayed 1.57 per cent copper, 0.12 gram per tonne gold, 3.2 grams per tonne silver and 0.0017 per cent molybdenum; four other samples less than 1 kilometre to the north-northeast yielded between 0.17 and 0.4 per cent copper (Assessment Report 35967).
Work History
In 1972, a fairly extensive work program was undertaken by Phelps Dodge Corporation of Canada Ltd on what later (in the 2000s) became the Greater Kopper claim of Charles Greig and Bernard Kreft (the Shaft North property). The Shaft North property contained The Late (104G 063) and Arc (104G 078) occurrences. The Phelps Dodge work occurred on the “Columbia River property” which had been optioned from Columbia River Mines Ltd. The claims consisted of Arc, Port and Rose. Phelps Dodge map and prospected the area which later became the Late Property. The Late showing would have been contained close or at the common boundary of the Arc 20 and Arc 5 claim (Map 5 and 8, Assessment Report 3985). The work program included prospecting, linecutting, geological mapping, a soil and silt geochemical survey, rock sampling, an induced polarization and resistivity survey, a magnetometer survey, cobra drill trenching, bulldozer trenching, helicopter pad and road construction, and diamond drilling. The focus of the grid work, and the geophysical surveys, was on the lower slopes of Mount LaCasse. A single hole was drilled near Grizzly Canyon. Phelps Dodge also ran an induced polarization and resistivity survey on the Arc and Rose grid in 1972, but only weak and apparently discontinuous anomalies were found (Assessment Report 3986).
In the late 1970s, claims covering the Paramount ground came open and were re-staked or optioned by Teck. They undertook work to trace mineralization northward through the Greater Kopper claim (shown in Assessment Report 30682), from a mineralized zone outlined to the south. The geological work from that program is presented in Assessment Report 6939 and the prospecting by Assessment Report 7869. Both reports noted that mineralization, in general, occurred along the contact zone between intrusive and volcanic rocks. Prospecting suggested that the zone represented a relatively narrow yet continuous extension northward of the mineralized zone known as the “Lacasse" zone. See the Schaft Creek North occurrence.
During 1981, the Late property, which was later held, in part, by the east-central Greater Kopper tenure of C. Greig and B. Kreft, was examined in a short program by Teck Explorations (Assessment Report 9660). Five chip samples for a total of 45 metres were collected and were assayed for copper, gold, silver, and molybdenum. Assessment Report 9660 notes that sparse mineralization occurred over the entire property but that it was most prominent along the contact and in shear/alteration zones. Mineralization within the volcanic rocks was significant only in areas adjacent to the intrusive contact.
In 2008, on behalf of Greig and Kreft, a work program consisted of the collection of 17 rock, 183 soil and 1 silt sample. This work plots in the area of the Late showing (104B 063) on the Greater Kopper claim. This claim was transferred to Copper Fox Metals in 2011.
In 2015, Teck Resources conducted geologic mapping, expanded outwards from the area that had been mapped in 2014. The mapping area extended along the margin of the Hickman Batholith and included two areas of focus: 1) the northern portion of Mount LaCasse; and 2) a mountain located south of the Schaft Creek deposit, colloquially named Mount Hicks. In total, 18 km2 was mapped at 1:5,000 scale. The mapping completed north of Mount LaCasse included field checking of several historically known mineralized showings, including the Grizzly and Greater Kopper areas.
In 2015, Teck collected 116 rock samples for analysis, 56 were taken from the Mount LaCasse area to the north, and 60 were taken from the Mount Hicks area to the south. 112 of these samples were taken directly from outcrop, with 1 subcrop and 3 float samples collected. Three of these samples occur in the immediate area of the Late MINFILE plot. Another 10 were taken about 300 metres to the northeast and down the ridge for about 1 kilometre to the north -northwest (Rock sample maps, Appendix IX, Assessment Report 35067). Most of the remainder of the 56 samples were taken more than 1 kilometre to the northeast of the MINFILE plot and less than 1 kilometre to the southeast.
