Rivers and their sediments part 2

Question 1

Discuss crevasse splay

Answer 1

If the breach isnt big enough to take all the flow from a river. They are delta like deposits which fine away from the channel, it is asymmetric as the floodplain has a gradient.

Question 2

Name some features you may see in a floodplain on sedimentary log

Answer 2

Sub aerial exposure - desiccation cracks.

Bioturbation, rooting, soil formation, waterlogging, thin sedimentary sheets

Question 3

what may you see interbedded with a floodplain?

Answer 3

crevasse plays, point bars

Question 4

What is the process of creating a soil called?

Answer 4

Pedogenesis

Question 5

Where do you find the most mature and immature soils?

Answer 5

Immature soils next to river channel, mature further away

Question 6

If a river is running in more than one channel what is this feature?

Answer 6

Anabranching

Question 7

Discuss anabranching

Answer 7

When a river is running in more than one channel

Question 8

If youre identifying a fluvial sequence in a sedimentary log what are you looking for?

Answer 8

Dominantly unidirectional currents, erosive bodies, pebble lags, subaerial exposure, fining up vertical sequence, q

Question 9

what can palaeocurrent directions tell you?

Answer 9

it tells you if youre looking at fluvial, but they cannot tell you the channel planform (braided or meandering)

Question 10

Is it easy to tell the river planform?

Answer 10

No, it is very difficult to identify if the river was braided or meandering