Ocean-Floor Sediments (19.3)

1. Ocean-Floor Sediments (19.3)

2. Sources of Deep Ocean-Basin Sediments • Refresher!!! What is a deep ocean-basin? • Part of the ocean floor that is under deep water beyond the continental margin. • Sediments usually finer • Collected using core samples • Samples show slow settlement and can be organic or inorganic

3. Core Samples A scientist studying a core sample that was collected by drilling into sediment layers on the ocean floor.

4. Inorganic Sediments • Rocks carried from land by rivers • Volcanic dust blown into ocean by wind • Glaciers pick up sediment iceberg deposit in ocean • Meteorites vaporize in atmosphere but creates dust that enters Earth’s atmosphere

5. Inorganic sediment deposited by a river in Indonesia

6. Biogenic Sediments • Majority of sediments on ocean floor are Biogenic • Biogenic: sediments that are the remains of marine plants and animals. • Most common compounds found in organic sediments are silica and calcium carbonate

7. Chemical Deposits • Chemical reactions in ocean produce solid materials that eventually settle to ocean floor as potato shaped lumps of minerals called nodules. • Nodules commonly located on abyssal plains.

8. Nodules Lumps of minerals that are made of oxides of manganese, iron, copper, or nickel that is found in scattered groups on the ocean floor.

9. Physical classification of sediments • Two basic types • (1) Muds: fine silt and clay sized particles of rocks. E.g. red clay • (2) Ooze: soft, fine sediment. E.g. biogenic materials • Calcareous ooze-made of calcium carbonate • Siliceous ooze-made of silicon dioxide.