|
Spec.
Publ. Int. Ass. Sediment. 10(1990), 281-295
PLEISTOCENE
GLACIAL FAN DELTAS IN SOUTHERN ONTARIO, CANADA
I.P. MARTINI
Department
of Land Resource Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
¡¡
 Stratified
ice contact and outwash deposits were commonly formed at the margins of the
Pleistocene ice-sheets that covered North America. Local advance and retreat of
the glacial terminus mimicked reactivation of faults and. erosion in
tectonically active areas. Examples are presented in this paper of foresetted
fan deltas which formed In lakes and seas near glacier terminus, fed by eskers
or other englacial streams, and at the end of outwash and 'valley trains' of
various lengths. The fan deltas treated here have similar foresets,
characterized by massive to parallel-bedded gravelly layers alternating with
openwork gravel and coarse sand lenses, mostly emplaced by mass flow. They vary,
however, in types of topsets (bouldery channel deposits or washed beach
gravels), and in the complexity of lateral and vertical facies transitions,
which is in part due to rapid change in recurring strong fluvial floods and to
rapid water-level changes of lakes or sea.
|
