Abstract

Detailed comparisons of individual facies and independently constructed facies sequences in the Devonian Battery Point Formation (BP) of Quebec and the South Saskatchewan River (SS) reveal both similarities and differences.

At the bottom of the summary facies sequence (BP) which was derived by Markov analysis, trough crossbeds correspond to the deposits of dunes in the deeper channels (SS). Solitary planar crossbed sets (BP) with paleocurrent directions which diverge from those of the trough crossbeds are analogous to deposits of oblique slipface-bounded bars in the channels (SS). Cosets of up to 4 sets of planar crossbeds (BP) resemble the stratification of complex sand flats (SS). Small planar crossbed sets near the top of the sequence (BP) correspond to deposits of sand waves, common in shallow areas of the river (SS). Interbedded mudstone and rippled sandstone near the top of the sequence (BP) resemble the fine-grained cohesive floodplain deposits (SS). Some asymmetric scour fillings and low-angle cross-stratified deposits (BP) are unlike any sediment in the river (SS).

The vertical arrangement of channels, sand flats, and floodplains in the river suggests facies sequences which are similar to the summary sequence (BP). Some observed sequences (BP) are more complex, reflecting rapid aggradation in the channels of the Battery Point river which promoted lateral migration of shallow channels over bars and sand flats.

A facies model for this type of sedimentation consists mainly of channel, bar, and sand flat deposits interfingering laterally and succeeding one another vertically. Minor amounts of cohesive floodplain sediments are also present. Lateral migration of the river back and forth while aggrading causes deposition of a sheet sand elongated parallel to the paleoflow.