Inputs from terrigenous, Glacial (Ice-rafted debris)
As glaciers retreat, sediment is released. Includes sediment scraped from bedrock as well as dust incorporated into ice in iceberg zone
Inputs from terrigenous, Turbidites
1. Rapidly-accumulated terrestrial sediments 2. Earthquake-triggered submarine avalanches 3. High velocity (~50 mph!), erosive events -Slide of loose sediment triggered by shocks then slide arrested on gentle slope then turbidity current formed from upper layers of slide flows onward. -Creates high velocity current that transports sediment.
Inputs from terigenous, sea level changes (listen on webcast)
Relict Terrestrial sediments: Get sediment types on the continental shelf that may not be seen in other parts of the continental slope or abyssal plain
Inputs from biogenous sediments, deffinition
Deff: Sediments of biological origins Also known as Biogenic OOZE
1. Accumulation depends on production and preservation 2. SiO2 is preserved everywhere 3. CaCO3 is variable,
What does accumulation rates of ooze depend on
It is highly variable 1. Productivity 1. reproduction of planktonic organisms 2. Preservation 1. silica dissolves only very slowly and is preserved everywhere 2. calcium carbonate depends on T, pH and varies with depth. 3. Rates are variable: <1 to 15mm/1000 yr
In biogenous input, what is the carbonate compensation depth?
1. The depth at which carbonate input from the surface waters is balanced by dissolution in corrosive deep waters 2. In today’s ocean this depth (CCD) varies between 3 km (polar) and 5 km (tropical)
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