LD - Lecture 3

Question 1

What’s the Hjulstrom diagram?

Answer 1

Classification of grain sizes and their erosion velocities

Question 2

Define Terrigenous sediment

Answer 2

Sands and Muds; Weathering and erosion of rocks on land

Question 3

Define Biogenic sediment

Answer 3

Muds and Oozes; hard remains of Organisms

Question 4

Define Authigenic sediment

Answer 4

Precipitated in chemical reactions in seawater

Question 5

Shelf sedimentation features (2)

Answer 5

Shallow, near terrigenous sources

Question 6

Ocean basin sedimentation features (2)

Answer 6

Deep, far from terrigenous sources

Question 7

What controls shelf sedimentation?

Answer 7

Tides, waves, currents - influence decreases with water depth

Question 8

When was the last age?

Answer 8

10 thousand years ago

Question 9

Relic sediments

Answer 9

Reflect an environment which no longer exists

Question 10

What sediment dominates tropics?

Answer 10

Biogenic

Question 11

What sediment dominates Polar regions?

Answer 11

Glacial

Question 12

Bulk Emplacement?

Answer 12

Large quantities are deposited as a mass

Question 13

Slump

Answer 13

Coherent mass

Question 14

Slurry

Answer 14

Loose debris flow that behaves like a viscous liquid

Question 15

Turbidity Current

Answer 15

Forms a turbidite, settling sediment in a characteristic pattern after an avalanche like settling

Question 16

Example of bulk emplacement (4)

Answer 16

Slumps, Slurries, Turbidity Currents, Iceberg Rafting

Question 17

What is pelagic sedimentation?

Answer 17

Open ocean e.g wind blown sahara dust