Sorting of Sediments and Deposition

Agents of Deposition The agents of erosion are also agents of deposition. Depositional rate depends on sediment size, shape and density. Depositional rate also depends on characteristics of the depositional agent. Speed or velocity

Agents of Deposition -

Settling Rate Vs. Velocity - Velocity Settling Rate

Settling Rate Vs. Density - Density Settling Rate

Settling Time Vs. Rate - Settling Time Settling Rate

Mountain side Stream Lake As the stream enters the lake or an ocean, the stream velocity decreases and sediments are deposited. S t r e a m v e l o c i t y d e c r e a s e s - Horizontal Sorting B o u l d e r s C o b b l e s P e b b l e s S a n d S i l t C l a y

Region of maximum stream velocity changes when streams bend or turn. There is an interface between regions of erosion and deposition… Stream Boulders Cobbles Pebbles Sand Vertical Sorting Clay Silt Vertical Sorting

- Latest layer Earliest layer Later layer Vertical sorting can occur as a single depositional event in still water or a series of events as when a stream’s velocity decreases through the seasons allowing particles to settle in a -

Vertical Sorting

- Named for the Greek letter Stream Ocean Deltas

Mississippi Delta Sediment-laden river water mixes with cold, deep- sea currents, creating a nutrient rich zone where both salt and freshwater fish flourish.

Wind-- - Deposition by other agents of erosion

Crossbeds in a Sand Dune

Unsorted Sediments - -

Final Question What are the factors that affect the settling rates of sediments? ---