1. Sediments

2. Ocean Floor Sediments Cosmogeneous - ~ 20 tons/day (Tektites) Hydrogeneous (from water) - black smokers, Manganese nodules (inorganic) Biogenous – silica, chalk, & limestone from plant/animal shells and skeletons Terrigenous = “lithogenous” >90% of ocean sediment; clay, silt, sand, gravel from fluvial runoff & glacial dropstones

3. Components of Open Ocean* Chalk/limestone Phytoplankton (autotrophs=plants) –Calcareous nannofossils (coccoliths & discoasters) – armored blue-green algal cells –Diatoms- algal cells enclosed in siliceous frustules (like a pill box) Zooplankton (heterotrophs=animals) –Foraminifera –calcareous shelled protozoa –Radiolaria – protozoa with rigid, siliceous skeleton –Pteropods and Heteropods – nectonic/planktonic snails (shells made of aragonite [CaCO3] Although list includes two siliceous components, the huge amount of the three calcareous players makes chalk predominantly calcareous. * Middle continental shelf & deeper

4. Ocean Floor Sediments Cosmogeneous - ~ 20 tons/day (Tektites) Hydrogeneous (from water) - black smokers, Manganese nodules (inorganic) Biogenous – silica, chalk, & limestone from plant/animal shells and skeletons Terrigenous = “lithogenous” >90% of ocean sediment; clay, silt, sand, gravel from fluvial runoff & glacial dropstones

5. Sampling Devices for Oceanic Rock/Sediment Chain dredge – (rock and lava) Clam shell/orange peel (sediment) very shallow & mixes sediment Box core – (sediment); 3-4’ sample intact Piston core – (sediment) 50-100’ max, good intact record Rotary drilling & coring (rock) – stationary platform or dynamic positioning platform; excellent record up to 10K’ below sea floor Riser drilling (rock) uses B.O.P. & riser to control dangerous hydrocarbon over pressures