Sea Floor

Part 3

Underwater volcanic eruption! COOL

• http://www.youtube.com/watch?v=hmMlspNoZMs

Trenches

Sediments

• Thicker the farther away from the ridge. • Two types – Lithogenous – Biogenous • Composed of CaCO3 or SiO2

Diatoms

Radiolarians

Foraminiferans

Coccolithophorids

Microfossils

• The organisms that produce biogenous sediments are microscopic or close to it.

• Sediment particles are sometimes called microfossils.

• Can determine past climate– Carbon dating– Ratios of magnesium to calcium, isotopes of

oxygen

Continental Margins

• Continental Shelf• Continental Slope• Continental Rise• Abyssal Plain

• Draw a diagram and label each margin – take notes on your diagram about its characteristics

Passive and Active Margins

Active vs. Passive Margins

• Active • Passive

Deep Ocean Basins

• The abyssal plain– Rises at a gentle slope towards the mid ocean

ridge system. • Flat with some channels, low abyssal hills,

plateaus and rises• Seamounts• Mariana Trench- 36,163 ft deep

Hydrothermal Vents

• Central rift valley• Black smokers• Life discovered around the hydrothermal vents

• http://www.youtube.com/watch?v=rFHtVRKoaUM