Page 255 - Fundamentals of Geomorphology

238 PROCESS AND FORM

()
a

1
2 1
2

()
b

1
2
Valley
5 floor 4
3

Figure 9.9 Paired and unpaired terraces. (a) Paired, polycyclic terraces. (b) Unpaired, noncyclic terraces. The terraces are
numbered 1, 2, 3, and so on.
Sources: Adapted from Sparks (1960, 221–23) and Thornbury (1954, 158)

c
() Time 1 () Time 2 () Time 3
a
b

Figure 9.10 Strath (bedrock) terrace formation. (a) Original V-shaped valley cut in bedrock. (b) Lateral erosion cuts
a rock-floored terrace. (c) Renewed incision cuts through the floor of the terrace.