British Columbia Ministry of Energy, Mines and Natural Gas and Responsible for Housing
News | The Premier Online | Ministries & Organizations | Job Opportunities | Main Index

MINFILE Home page  ARIS Home page  MINFILE Search page  Property File Search
Help Help
File Created: 16-Nov-1988 by Laura L. Duffett (LLD)
Last Edit:  10-Aug-2020 by Karl A. Flower (KAF)

Summary Help Help

BCGS Map 104B056
Status Showing NTS Map 104B10W
Latitude 056º 34' 47'' UTM 09 (NAD 83)
Longitude 130º 57' 05'' Northing 6272308
Easting 380133
Commodities Copper, Gold, Silver, Zinc, Molybdenum Deposit Types K01 : Cu skarn
I05 : Polymetallic veins Ag-Pb-Zn+/-Au
Tectonic Belt Intermontane Terrane Stikine, Plutonic Rocks
Capsule Geology

The Pyramid Saddle occurrence is located approximately 93 kilometres northwest of Stewart, British Columbia, in an area referred to as the Bronson Corridor. Pyramid Saddle is located approximately 3 kilometres south of Inel (MINFILE 104B 113), 8.5 kilometres southeast of the past producing Johnny Mountain mine (MINFILE 104B 107), and 14 kilometres southeast of the past producing Snip mine (MINFILE 104B 250). The Pyramid Hill occurrence (MINFILE 104B 207) is located 600 metres to the northeast.

The area is underlain by an undivided assemblage of sedimentary and volcanic rocks ranging from Upper Triassic to Jurassic in age, which are intruded by Middle Mesozoic phases of the Coast Plutonic Complex.

The stratified rocks are composed of submarine to sub-aerial fragmental volcanic rocks that are interlayered with sequences of argillite, banded siltstone, greywacke, conglomerate and minor impure limestone which are thought to be correlative with the Lower Jurassic Hazelton Group, Unuk River Formation or the Upper Triassic Stuhini Group.

Structurally, the rock units have a general northwest trend and have undergone regional greenschist facies metamorphism. They are strongly deformed and are cut by numerous northeast trending faults and fractures.

Pyramid Hill is underlain mainly by a southwest dipping, 450 to 500 metre thick succession of sedimentary and volcaniclastic rocks. The sedimentary rocks are predominantly thin-bedded, locally calcareous, pale to dark grey siltstones grading upwards into tuffaceous siltstones. Higher in the succession, the sequence is characterized by massive tuffs and lapilli tuffs. Numerous granodiorite and orthoclase porphyry dike-like apophysis of the Coast Plutonic Complex intrude both the siltstone and volcaniclastic units.

Varying degrees of sulphide-bearing skarn alteration is developed within the volcaniclastics and tuffaceous siltstones in areas adjacent to the intrusions. Skarn alteration is comprised of massive, medium-grained chlorite plus or minus diopside with lesser amounts of quartz and epidote, isolated clusters of coarse, brown garnet, scattered tremolite-actinolite and sulphides.

The basal siltstone unit is hornfelsed with secondary biotite, is siliceous and hosts pyrite-rich areas adjacent to the intrusives.

The skarn related mineralization at Pyramid Hill appears to be stratabound and has selectively followed a sequence of tuffs and lapilli tuffs within a bedded succession of siltstones and tuffaceous siltstones. Gold-bearing sulphides, predominantly pyrite and chalcopyrite, occur as fine-grained disseminations, masses, veins and vein- lets concentrated along the contacts between dykes and skarn-altered volcaniclastics.

A grab sample taken from chlorite-epidote plus or minus diopside skarn-altered volcaniclastic rock with 5 per cent pyrite and minor chalcopyrite assayed 1.204 per cent copper, 18.4 grams per tonne silver and 1.62 grams per tonne gold. Another grab sample from quartz stockwork infills within a 1.0 metre wide shear in banded siltstone with patches of malachite assayed 0.315 per cent copper, 16.8 grams per tonne silver and 0.395 gram per tonne gold (Assessment Report 16931).

Continuous chip sampling within the Pyramid Saddle area was concentrated within the skarn-altered volcaniclastics which host pyrite, chalcopyrite, malachite and minor sphalerite within veins, quartz stockworks and as disseminations. Chip samples indicated anomalous copper and gold values. A 1.0 metre chip sample from PYCH-60 assayed 0.17 per cent copper, 1.0 gram per tonne silver, 0.075 gram per tonne gold and another 1.0 metre sample assayed 0.294 per cent copper, 2.9 grams per tonne silver and 0.33 gram per tonne gold (Assessment Report 16931, Figure 8).

Exploration by Colorado Resources Ltd. in 2014 and 2015 included rock and channel sampling around Pyramid Hill and Pyramid Saddle as part of the larger KSP project. A rock sample of black argillite with chalcopyrite on fractures and quarts veinlets reported 0.49 per cent copper and 519 parts per billion gold (sample 2639754). Channel CH14-008B, cut into chloritized and silicified diorite with pyrite and local quartz-pyrite veins reported 11.7 metres grading 0.126 per cent copper and 191 parts per million molybdenum. The general Pyramid Hill area is elevated in molybdenum, with 78 rock samples collected in 2014 reporting an average of 93 parts per million molybdenum (Assessment Report 35184).

EMPR ASS RPT 11313, 11332, 13728, 14055, *16931, *35184, 35943
EMPR EXPL 1983-525,526; 1985-C380,C381
EMPR FIELDWORK 2015-1 pp. 41-58
EMPR PF (*Peterson, D.B., (1987): Report on Gossan Gold Project, Liard Mining Division, Northwestern British Columbia for Western Canadian Mining Corporation, Nov. 1987; Western Canadian Mining Corporation First Annual Report, 1987; Western Canadian Mines Corporation, Rights Offering Circular, Aug.16, 1988)
GSC MAP 9-1957; 311A; 1418A
GSC P 89-1E, pp. 145-154
GCNL #68,*#132, 1987; #214, 1985; Nov.19, 1987
N MINER Apr.19, 1984
Anderson, R.G., (1988): A Paleozoic and Mesozoic Stratigraphic and Plutonic Framework for the Iskut Map area (104B), Northwestern British Columbia, pp. A1-A5, in Geology and Metallogeny of North- western British Columbia, Smithers Exploration Group, G.A.C. Cordilleran Section Workshop, October 16-19, 1988
World Investment News, May 1987
Burgoyne, A.A. (2012-05-07): Technical Report on The Iskut Property with Special Reference to Johnny Flats & Burnie Trend Targets