Ocean Basins And Sediments

Question 1

Pangaea?

Answer 1

Large single land mass 200MA, broke up 150MA creating new oceans

Question 2

Why was continental drift rejected?

Answer 2

No known driving mechanism so the motion wasnt accepted.

Question 3

Sea floor spreading?

Answer 3

Central rift valley - fresh basalt
high heat flow
geologically active
magnetic anomalies

Question 4

What is the sea floor spreading rate?

Answer 4

1 - 10 cm per year

10 - 100 km per M years

Question 5

Where are the shallow weak disturbances?

Answer 5

MORs

Question 6

What occurs at the deep strong disturbances?

Answer 6

tectonism - buckling, folding, faulting, crushing
deep sea trenches and island arcs
subduction zones

Question 7

What is the driving mechanism?

Answer 7

Thermal convection in the mantle

Question 8

Terrigenous?

Answer 8

From land

Question 9

Biogenic?

Answer 9

From organisms

Question 10

Authiogenic?

Answer 10

Precipitated in chemical reactions

Question 11

volcanogenic?

Answer 11

From volcanoes

Question 12

cosmogenous?

Answer 12

From outerspace

Question 13

Authigenic sedimentation?

Answer 13

Manganese nodules
20-30% iron
cocentric layers of metal oxide around nucleous
found on continental shelf and upper slope

Question 14

Bulk emplacement?

Answer 14

slumps / slurries / turbidity currents (submarine canyons + turbidites) / ice rafting