From last week… (Oberlander)

• Pediments form as a result of a different past climatic condition, followed by a period of regolith stripping.

• The processes we see acting today are not those that were active during pediment development.

This week… (Strudley and Murray 2007 Geomorphology)

• Pediments are created by current climate conditions and processes.

• Piedmont break is a result of transition from weathering to transport limited conditions

• Humped soil production functioin gives rise to tor and inselberg spotted landscape

• Specific set of circumstances on pediment (high infiltration, non-cohesive banks) gives rise to branching channel systems, precludes mature incision on these surfaces

20 cm/yr; low I; open

50 cm/yr; low I; open

508 cm/yr; low I; open 508 cm/yr; high I; open

50 cm/yr; high I; open

20 cm/yr; high I; open

102 cm/yr; low I; incis.

50 cm/yr; low I; incis.

20 cm/yr; low I; incis. 152 cm/yr; low I; incis.

254 cm/yr; low I ; incis.

508 cm/yr; low I ; incis.

20 cm/yr; high I; incis

50 cm/yr; high I; incis

102 cm/yr; high I; incis

152 cm/yr; high I; incis

Interactions between climate, vegetation, soil properties, sediment transport, and bedrock weathering are not modeled

• How might these interactions affect modeling of pediment development in different climate environments?

How can we test the hypothesis that incision rates at of the Colorado River exceeded integrated sediment flux (weathering and sediment transport) which is inferred to hamper pediment development?

Pediments are found in limestone bedrock landscapes. What implications does this have on for dissolution vs mechanical weathering rates?

Some questions…