CAS ES 105 Lecture Notes - Lecture 6: Mid-Ocean Ridge, Radiolaria, Estuary
30 Jul 2018
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Document Summary
Silica in biogenic sediments: diatoms (algae) Live on surface waters and when they die, sink to the bottom diatoms are large so sink quickly but not as fast as sand grain. Calcium carbonate in biogenous sediment: coccolithophores (algae) Can make a new shield every 15 min. Take the caco3 in shells and deposit it at the bottom: foraminifera(protozoans) White cliffs of dover made of caco3 from coccolithophores and foraminifera. Ccd of calcium carbonate compensation depth: cold water holds more gas, pressure increases further down, so more gas can be held (more co2) at bottom lower ph/acidic waters, caco3 shell + acid waters = dissolved. ~4500m seawater is too acidic and caco3 dissolves. Sio2 ooze protects caco3 ooze that spreads out from mid ocean ridge. Ccd is more shallow in pacific its older, deeper and colder more time for co2 to build up more co2 going into it deeper and more co2 to build up since it is colder.
