Lecture 14 - Deep Sea Sediments part 2 Flashcards
What are calcerious oozes formed of?
Calcium carbonate
What makes this calcium carbonate
Coccolithophers ( algea, nanofossils, photic zone)
Foraminferua (unicelluar zoo plankton )
Pteropods (panktotic gastropods, surface waters)
Properties of calcerious ooze
More souble in cold waters, high pressure, acidic water
what controls the distribution of calcerious oozes
The same as before, plankton live in surface, then die and sink. Bacteria oxidse organic matter relaesing co2
What is needed for carcluim carbonate preseration
It occours in warmed shallower waters
atlanitc ocean more than pacific
Explain the calcite compesation depth
This is the depth at which no calcite can be preserved in ocean sediments. Above the CCD the rain rater is greater than the dissoultion and below its reverse
What is the Climap project?
looks at how diferent was the eath during the last glcial maximum
What was different back then
High lat ice sheets to do not directly effect the tropical temps, lower tropic temps as a result of CO2.
What did the climap project use?
it use calcite deposits in sedimentary records to calculate the temp and depth of the sea water
what is the MARGO protect
Combined lots of different work with modern geochemical techniques
What are terrigenous sediments
Weathing and erosion of land ares whichh is gravels and sands etc, sediments are transported to the ocean by rivers and deposited on the shelves and slopes
What is ice rafted debris
Sediment is transported by ice berg and is dropped when the ice berg melts, therefore they are subject to sediment source and ocean currents
During ice house worlds what is depleted in sea waterq
Oxygen - 16
In green house world what is seawater enriched in?
oxygen - 16
What can these oxygen isotopes tell us
THey can be used to study the earths climate histrory
