GEOMORPHOLOGY, SEDIMENTARY STRUCTURES, AND GENESIS OF DOME DUNES IN WESTERN CANADA

Dome dunes in four stabilized, inland dune fields in western Canada ar e predominantly composed of horizontal to low-angle cross-strata, indi cating that slip f ace development was rare. Dip angles of lee side de posits decrease upward in the dome dunes. The spread of dip directions increases with elevation in the dunes, spanning 360-degrees for topse t deposits. Sedimentary structures indicative of moisture (adhesion la minae) and vegetation (scour surfaces) occur in the dunes and denivati on features are also present. Sediment adhesion is responsible for the maintenance ot the dome morphology. Sediment sorting within the dome dunes is poorer than in other local dune types in the vicinity, sugges ting that less reworking/ineffective selective transport occurred and that the dome dunes are more efficient in retaining sediment. The rari ty of slip face and grainfall deposits and the abundance of low angle deposits indicate that preferential accumulation of sediment at the to p of the lee side did not occur. Development of domal morphology is a consequence of the inhibition of slip face development. In inland, rel atively moist boreal environments, the primary factor limiting or prec luding sediment accumulation at the crest ot the dunes is a low rate o f sedimentation.