270 likes | 424 Views
Topic 9 Deposition. Regents Earth Science. deposition. Is the “dropping” of transported materials Or the processes by which transported materials are left in new locations. Factors Affecting Deposition. Particle size.
E N D
Topic 9 Deposition Regents Earth Science
deposition • Is the “dropping” of transported materials • Or the processes by which transported materials are left in new locations
Particle size • Larger particles settle more quickly than smaller particles (if they have the same shape and density) • Colloids remain suspended indefinitely Settling Time Settling Rate Particle Size Particle Size
Particle Shape • Particles of the same size and maximum diameter will settle out in this order: round, oval, flat • The more spherical the particle, the faster the settling rate. • As flatness increases, settling time increases.
Particle density • The denser the particle, the faster it will settle in particles that have the same size and shape.
The rate at which particles are deposited by a stream is least affected by • 1. size and shape of the particles • 2. velocity of the stream • 3. the stream’s elevation above sea level • 4. density of the particles
A mixture of sand, clay, pebbles, and silt, of uniform shape and density, is dropped from a boat into a calm lake. Which material most likely would reach the bottom of the lake first? • 1. sand • 2. pebbles • 3. clay • 4. silt
sorting • the separation of particles during deposition
In sediments of mixed sizes, shapes, and densities • Roundest, largest, and densest particles will be at the bottom of each layer. • Smallest, flattest, and least dense will be at the top of each layer.
Vertical sorting • Sorting from top to bottom throughout a layer
Graded bedding • Layers of sediment that are each vertically sorted • Usually occurs in shallow, quiet bodies of water or in the ocean • Degree of sorting is usually greater in the bottom layer than in the top layer
Horizontal sorting • The sorting of sediments into layers in which the particles are sorted horizontally, ranging from largest to smallest in the direction of travel of the transporting agent
delta • A deposit formed at the mouth of a river as it empties into a quiet body of water • Named for the Greek letter delta
Alluvial fan • A deposit of sediment formed where the velocity of a river slows as it flows out of the mountains onto the flatland • Also called a land delta
Sediments deposited by water are • well sorted (either vertically or horizontally) • rounded • smooth • may show graded bedding