1. SEAFLOOR SEDIMENTS Lithogenous Biogenous Hydrogenous Cosmogenous

2. General patterns Review shape of typical ocean floor Lots of sediments near continents Few sediments at ocean ridges – Why?

4. Lithogenous (1) From weathering and erosion of continents Some relatively close to continental mass ◦ Beach sediments ◦ River sediments ◦ Glacial debris ◦ Graded bedding from turbidity currents

5. Turbidity currents and graded bedding Turbidity currents and graded bedding

6. Lithogenous (2) Some found on abyssal plain ◦ Wind-blown debris ◦ Red clays

7. Biogenous sediments (1) Remains of formerly living organisms (shells and reef material) Silica rich: radiolarians, diatoms Calcium carbonate rich: ◦ forams, coccolithophores, reefs ◦ carbonate compensation depth

8. RADIOLARIAN

9. DIATOMS

10. FORAMS

11. COCCOLITHS

12. Biogenous (2) Difficult to accumulate biogenous oozes Productivity of that area of the ocean Destruction as “shells” fall to seafloor Additional CCD for carbonate sediments Dilution by other sediments

14. Hydrogenous sediments Evaporites Manganese nodules Phosphorite nodules Metal sulfides

15. Manganese Nodules

16. Cosmosgenous sediments Meteorites Tektites Random distribution and relatively insignificant TEKTITES

17. MAP OF SEDIMENTS IN OCEAN Student version

18. Resources from the seafloor What is accessible? What is owned by whom? What is economically valuable?