Geology Reference
In-Depth Information
(A)
Syngenetic
Ice wedges
Sea/River
level
River
level
5 m
10 m
10 m
Frozen ice-rich
sand
Slumped
material
5 m
Frozen ice-rich
silt/clay
River deposits or
coastal sediments
Peat/surface
organic layer
Permafrost
(B)
Figure 10.4.
Fluvio-thermal erosion. (A) Forms of lateral and thermal riverbank and coastal
erosion. (B) Coastal erosion by thermo-erosional undercutting and block collapse along ice wedges
aligned parallel to the coast, Maitland Bluffs, Mackenzie Delta region, Canada.
with the other north- and west-fl owing rivers on Banks Island, which are all braided. The
reason is that the middle reaches of the Thomsen River are incised within relatively con-
solidated shale (Christopher Formation) while west-fl owing drainage dissects either glacial
materials or unconsolidated sand and gravel (Beaufort Formation). Thus, the availability
