DEPOSITION Mr. DeMarco
Deposition: -Process by which sediments are released or dropped from an erosional system.
Deposition occurs when the velocity of the water decreases. *This occurs when the stream or river flows into a larger body of water.
Characteristics of the sediments: SIZE SHAPE DENSITY
SIZE Larger particles will settle out first. Dissolved materials may remain in solution. 1st Last
SHAPE Spherical sediments settle out first, while flatter sediments will settle out last. last 1st
DENSITY Higher density sediments settle out first. 1st last GOLD ALUMINUM
THREE TYPES OF SORTING: What is sorting?
Sorting of Sediments Vertical Sorting: the roundest, largest, and densest particles settle at the bottom of a layer, while flatter, smaller, less dense particles settle on the top (landslide, underwater landslides)
Particle Size (Calm Body of Water) Water Smallest Particles Small Particles Medium Particles Largest Particles
Graded Bedding: -Vertical layering, largest sediments towards bottom. -Occurs when an erosional system stops abruptly.
Windward side Leeward side
HORIZONTAL SORTING How can I remember which way is horizontal? horizon
HORIZONTAL SORTING Stream enters a large body of water, the velocity decreases and deposition occurs Larger sediments are deposited first Delta may form
HORIZONTAL SORTING -Larger, more dense sediments settle out first, with a decreasing sediment size horizontally -Occurs when the velocity of the water erosional system decreases slowly (such as a stream flowing into an ocean) -Sediment size decreases in the direction the erosional system was flowing.
Types of Deposition • Horizontal Sorting River Mouth – Water velocity decreases
Deposition will occur on the inside of a meander where the water is moving more slowly
Inside bend– deposition creates a point bar (beach-like) Outside bend- erosion creates a cut bank (steep slope)
Alluvial fans form when streams come out of mountains onto flat land – velocity slows and deposition occurs
Types of Deposition Unsorted – Associated with glacial deposits • UnSorted