ABSTRACT

Evaporites and carbonates deposited in two Devonian basins of western Canada occur as (1) peripheral evaporites with basin-filling carbonate, or (2) peripheral carbonate with basin-filling evaporite, and reefs.

The Upper Devonian (D-1) Stettler Formation provides an example of a limestone-filled basin on the periphery of which are evaporites (microdolomite, nodular anhydrite, some halite) having those characteristics which we associate with modern sabkhas of the Arabian Gulf.

Deposits associated with the first stage of reef growth in the Upper Elk Point basin (Middle Devonian) provide an example of the second kind. The sedimentary units were deposited as follows: 1, platform; 2, reef, ending with laminar dolomite on both reef and basin-floor; 3, bituminous calcitic and anhydritic laminites on basin-floor (not on reef-sites); and 4, laminar halite filling interreef tracts nearly to reef-top level. During calcitic laminite and salt accumulation the reefs were sub-aerially exposed. Further reef stages supervened.