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Sediments of the Ocean. Chapter 5. Are particles of organic or inorganic matter that accumulates in a loose unconsolidated form Originates from: Weathering Erosion Living organism. Volcanic eruptions Chemical process Outer space. Sediments of the Oceans.
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Sediments of the Ocean Chapter 5
Are particles of organic or inorganic matter that accumulates in a loose unconsolidated form Originates from: Weathering Erosion Living organism Volcanic eruptions Chemical process Outer space Sediments of the Oceans
Erosion, Transportation, and Deposition • Water delivers the vast majority of particulate and dissolved material to the sea. • Wind transports only a small fraction of the sediment reaching the oceans • Glaciers: In polar regions, they deliver considerable quantities of coarse sediment.
Larger particles require more energy to be moved (fig. 5.5) • The energy is supplied by moving water or wind. • The faster the water or wind, the larger size particle can be picked up.
B) Non-mineralsa. Organic: contains C (carbon) and H (hydrogen), • Ex.:plant matter, algal matter (oil)
b. Inorganic: lacks the crystalline structure (= glass) examples: volcanic ash; the silica (SiO2) of diatom shells
Turbidites • Turbidity Currents: play an important role in transporting sediment to deep ocean • Turbidity Currents are density currents: a flowing mixture of sediment and water which is denser than surrounding water.
image of a turbidity current moving down the continental slope off California
Like rivers, they seek lowest point. • Characteristics of Turbidite deposits: graded bedding • Turbidity currents occur catastrophically. • Associated features: submarine canyons, fans, levees
Calcite (calcareous) particles dissolve in deeper ocean water. • The pteropods go first, followed by the forams, and, lastly, the coccoliths. • The water depth at which all of the forams dissolve is called the lysocline.
The water depth at which the coccoliths dissolve is called the Calcium Compensation Depth, the CCD (fig. 5.9)