SEDEX  SILVER-LEAD-ZINC  ORE

 

British Columbia’s 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 “exhaled” 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° 42’ 36” North, 115° 59’ 58” 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.

 


 

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