Composition of the Seafloor

1. Composition of the Seafloor Types of Sediment

3. Four types of sediments • The ocean floor is composed of basaltic rock that is covered by sediment. • Hydrogenous sediments • Biogenous sediments • Terrigenous sediments • Cosmogenous sediments

4. Hydrogenous Sediments • Result from _____________reactions within seawater • The reactions cause minerals to come out of solution and form particles that settle on the bottom • Sources include the dissolution of submerged ________and ____________, materials coming from new _________ forming at mid-ocean ridges, chemicals dissolved in _____________ vent water and material dissolved in

5. Biogenous Sediments • Biogenous sediments originate from _____________ • Primarily deepwater sediments • The particles come from shell and hard skeletons • Majority come from _____________organisms that contain silica (siliceous) or calicum carbonate (calcareous) • Over time, biogenous sediments become ______________ and ______________

6. Calcareous ooze

7. Terrigenous Sediments • Terrigenous sediments come from the _________ • Result primarily from erosion by water, wind, and ice • Deposited primarily on the continental shelves

8. Cosmogenous Sediments • Cosmogenous sediments come from ____________ __________(cosmic dust) • May contain microtektites, which are glass particles that form when a large meterorite impacts Earth • Cosmogenous sediments are the ____________ abundant of the sediments