ABSTRACT

A bed of well sorted limestone pebble conglomerate one meter thick and over 175 m long exposed among Ordivician argillites at Cap-des-Rosiers contains from base upwards 7 zones, each with distinct depositional features: Zone 1--carbonate sandstone infilling sole marks; Zone 2--imbricated coarse-grained pebble conglomerate; Zone 3--coarse grained pebble conglomerate without preferred clast orientation; Zone 4--coarse-grained pebble conglomerate with clasts orientated parallel to the Zone 4-Zone 5 contact; Zone 5--fine-grained pebble conglomerate with clasts oriented parallel to the Zone 4-Zone 5 contact; Zone 6--fine-grained pebble conglomerate without preferred clast orientation; Zone 7--sandy fine-grained pebble conglomerate. The zonation was produced during gravel flow emplacement b the falling in of sand between pebbles, the size separation of coarse- and fine-grained conglomerate, deformation during deposition along the interface between coarse- and fine-grained conglomerate, and suspension settling of sand. from and overriding current of water.