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Bella
Coola &
Laredo Sound
NTS 093D & 103A |
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| The Bella Coola (093D) and Laredo Sound (103A) map areas contain 45
recorded mineral occurrences. The region is underlain by the Paleozoic to
Tertiary Coast Plutonic Complex. Paragneisses of (?)Paleozoic age, younger deformed
metasediments and volcanics related to the Stikinia terrane are interspersed within the
plutonic complex. The westernmost portion (103A) of the area is underlain by Triassic
metasedimentary rocks of the Alexander terrane. The northeastern part is underlain by
Jurassic Hazelton Group mafic volcanic and sedimentary rocks and Lower Cretaceous Gambier
Group felsic volcanics. Pendants of the Hazelton and Gambier groups are abundant within
Coast Plutonic Complex along its eastern boundary zones. These rocks are variably
deformed, containing both northeast and northwest trending structures. Copper
and molybdenum showings occur in quartz veins hosted by diorite, quartz diorite and
granodiorite of probable Triassic age and in fractures and veins in hornfelsed Hazelton
volcanics. Molybdenum also occurs in quartzose shears hosted in Coast Plutonic Complex
rocks. The massive sulphide prospect Nifty
(093D 006) and associated showing, the Keen
(093D 007) and Jamtart
(093D 023), are hosted in a roof pendant of Hazelton Group volcanics and greenstone.
Copper and silver occur in biotite granite porphyry dikes at the Bella
Coola Chief (093D 009) occurrence. Magnetite, copper, molybdenum, gold and
silver are hosted in garnet epidote skarns. A pegmatitic stockwork, anomalous in uranium,
cuts skarn and granodiorite at the Promise
Well (093D 012) showing. Minor asbestos is hosted in a serpentinite of
unknown affinity. Limestone has been mined at Beale's
Quarry (093D 008) and at the Laredo
(103A 001) limestone deposit.
Six showings of vein graphite occur in a 33-kilometre long northwest-trending
linear pattern, from the bend in Mussel Inlet, southeast across the east end of Kynoch
Inlet. They are the Giant
(103A 011), Gem
(093D 019), Grey
Giant (093D 020), Zenith
(093D 021), Black
Lead (103A 010) and Green
Giant (093D 018). The showings lie on or near the trace of the inferred southern
extension of the Work Channel lineament (GSC Map 1712A), as are the graphite showings Elcho
Harbour (093D 028) and Bentinck
Arm (093D 027), further south on the map sheet, and the AA
graphite prospect (092M 017) on map sheet 092M to the south. |
References:
Gareau, S.A. (1991): The Scotia-Quaal metamorphic belt: a
distinct assemblage with pre-early Late Cretaceous deformational and metamorphic history,
Coast Plutonic Complex, British Columbia; Canadian Journal of Earth Sciences, Vol
28, pages 870-880.
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