SEDEX SILVER-LEAD-ZINC ORE
British ColumbiaÕs Sullivan Mine targeted a massive
sulfide deposit consisting of silver, zinc, and lead ore minerals. The
ore rocks have interesting contorted banding. This is an unusual example
of a sulfide deposit having a sedimentary origin. The Sullivan
Deposit is a SEDEX deposit, which stands for sedimentary exhalative
deposit. It formed by seafloor deposition of silver, zinc, and lead
sulfide mineral grains ÒexhaledÓ from underwater vents somewhat akin to black
smokers. At the Sullivan Deposit, SEDEX deposition occurred in the
collapsed crater of a mud volcano formed by emplacement of regional gabbroic sills
into wet, unconsolidated, seafloor sediments that were filling a continental
rift basin - a bit of a complex geologic origin. The folded and contorted
bedding seen in the sulfide layers formed by soft-sediment slumping.
Stratigraphy & Age: lower member-middle member boundary of the Aldridge
Formation (a turbidite-sill succession), Mesoproterozoic, 1470 Ma.
Locality:
Sullivan Mine, between Mark Creek and Sullivan Hills, just north-northwest of
Kimberley, East Kootenay District, Belt-Purcell Intracratonic Rift,
southeastern British Columbia, southwestern Canada (49¡ 42Õ 36Ó North, 115¡ 59Õ
58Ó West).
Banded silver-lead-zinc ore (field of view: ~5.7 cm across) from the Sullivan
Deposit with contorted bedding from soft-sediment slumping.
Very dark gray = argentiferous galena (Pb,Ag)S
Dark grayish brown bands = sphalerite (ZnS)
Dull brassy area at bottom of photo = pyrrhotite (Fe1-xS)
Banded silver-lead-zinc ore (field of view: ~2.3 cm across) from the Sullivan
Deposit with contorted bedding from soft-sediment slumping.
Very dark gray = argentiferous galena (Pb,Ag)S
Dark grayish brown bands = sphalerite (ZnS)
Dull brassy wisps = pyrrhotite (Fe1-xS)
Banded silver-lead-zinc ore (field of view: ~2.5 cm across) from the Sullivan
Deposit with contorted bedding from soft-sediment slumping.
Very dark gray = argentiferous galena (Pb,Ag)S
Dark grayish brown bands = sphalerite (ZnS)
Dull brassy wisps = pyrrhotite (Fe1-xS)
Banded silver-lead-zinc ore (field of view: ~3.9 cm across) from the Sullivan
Deposit with contorted bedding from soft-sediment slumping.
Silvery-gray = argentiferous galena (Pb,Ag)S
Very dark bands = sphalerite (ZnS)
Banded silver-lead-zinc ore (field of view: ~2.0 cm across) from the Sullivan
Deposit with contorted bedding from soft-sediment slumping.
Silvery-gray = argentiferous galena (Pb,Ag)S
Very dark bands = sphalerite (ZnS)
Info. mostly synthesized from:
Lydon, J.W. 2004. Genetic models for
Sullivan and other SEDEX deposits. pp. 149-190 in Sediment-Hosted
Lead-Zinc Sulphide Deposits, Attributes and Models of Some Major Deposits in
India, Australia and Canada. Narosa Publishing House. New
Delhi.