1. The Ocean Bottom Marine Science Pg 23 in Notebook Marine Science Pg 23 in Notebook

2. Review  3 layers of earth  Core  Mantle  Crust  Rock Cycle  Igneous Rock  Sedimentary Rock  Metamorphic Rock  Continental Drift  Plate tectonics  Sea floor Spreading  3 layers of earth  Core  Mantle  Crust  Rock Cycle  Igneous Rock  Sedimentary Rock  Metamorphic Rock  Continental Drift  Plate tectonics  Sea floor Spreading

3. HMS Challenger: 1872-1876 The beginning of systemtic observations of the ocean & ocean floor

4. Sir John Murray (1841-1914) gave detailed account of deep sea sediments recovered during the HMS Challenger expedition.

5. Sediments and Sedimentary Rock  Make up  8% of the Earths crust  75% of the Earths surface  Make up  8% of the Earths crust  75% of the Earths surface

6. Types of Sediments  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the eject of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the eject of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth

7. Terrigenic Sediment  Terrigenic sediment is the sand, silt, and clay you normally think of as sediment.  Quartz (SiO 2 crystall, “Silica”) is the dominant mineral in terrigenic sediment.

8. Terrigenic Sediment

9. Types of Sediments  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the eject of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the eject of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth

10.  macroscopic:  bones, teeth, shells of larger organisms rare  microscopic:  shells and skeletons of planktonic organisms  chief producers are  algae (plants, photosynthesizing)  protozoans abundant  macroscopic:  bones, teeth, shells of larger organisms rare  microscopic:  shells and skeletons of planktonic organisms  chief producers are  algae (plants, photosynthesizing)  protozoans abundant Biogenic Sediment

11. CaCO 3 producers: Coccolithophores 20  m

12. CaCO 3 producers: Foraminifera 50  m ~400  m

13. Types of Sediments  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the eject of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the eject of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth

14.  derived from dissolved material in sea water Manganese Nodules Evaporites Phosphates Carbonates Metal Sulfides  derived from dissolved material in sea water Manganese Nodules Evaporites Phosphates Carbonates Metal Sulfides Authigenic Sediments

15. Types of Sediments  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the ejections of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth  Terrigenic sediment produced by the break down of rocks on land  Biogenic sediment produced by organisms  Authigenic sediment produced in place by chemical reactions in seawater or within the upper sediment  Volcanogenic sediment produced from the ejections of volcanic eruptions  Cosmogenic sediments produced from cosmic debris that constantly bombards the Earth

16. derived from extraterrestrial sources macroscopic: meteor debris rare microscopic: space dust (spherules, tektites) constantly raining on Earth  derived from extraterrestrial sources macroscopic: meteor debris rare microscopic: space dust (spherules, tektites) constantly raining on Earth  Spherule Cosmogenic Sediments

17. Distribution of Sediments  Ten times more terrigenic than biogenic sediment arrives at the seafloor each year.  If this sediment was distributed evenly, then terrigenic sediment would dominate the sediment cover of the seafloor.  This is not the case because of most of the terrigenic material is trapped along continental margins.  Ten times more terrigenic than biogenic sediment arrives at the seafloor each year.  If this sediment was distributed evenly, then terrigenic sediment would dominate the sediment cover of the seafloor.  This is not the case because of most of the terrigenic material is trapped along continental margins.

18. © The Open University

20. Importance of Sediments  Economic Value  Oil, fossil fuels  Salt & Phosphorus deposits  Determine shape & structure of Ocean bottom  Strongly affect distribution of Benthic Organisms  Chronological record of Earth’s history  Tectonic history  Climate history  Evolutionary history  Economic Value  Oil, fossil fuels  Salt & Phosphorus deposits  Determine shape & structure of Ocean bottom  Strongly affect distribution of Benthic Organisms  Chronological record of Earth’s history  Tectonic history  Climate history  Evolutionary history

21. Sediment Thickness

23. 20 000 500

24. Continental Shelf/ Slope CLCS/11, Fig. 8.1

25. Law of Superposition Younger sediments over Old sediments YOUNG ---------------------- OLD Younger sediments over Old sediments YOUNG ---------------------- OLD

26. Sediment Classification  By Grain Size  By Origin  By Grain Size  By Origin

27. Sediment Classification  Grain Size  Clay <4 μm  Silt 4-62 μm  Sand62-2000 μm  Gravel>2000 μm  Grain Size  Clay <4 μm  Silt 4-62 μm  Sand62-2000 μm  Gravel>2000 μm

28. Table 3.1

29. Ternary diagram with gravel Sediment Classification based on size Sediments are often mixtures of various grain sizes !

31. Seamount  Ocean bottom mountains

32. Oceanic trenches