Weathering, Erosion and Deposition

Types of Weathering Physical Chemical Abrasion – like sand paper Glaciers – those big frozen masses of ice Exfoliation – rock layers flake off Wedging – water gets into something and freezes making it bigger Chemical Oxidation – reacting with oxygen, think of rusting Acid precipitation – acid rain from pollution

Physical Weathering Something that causes larger rocks to break into smaller rocks. Can be water that gets into cracks and freezes causing it to split, called ice wedging or frost wedging. Also, can be water that constantly flows over an area; it washes small parts of the rock away until it breaks (abrasion) Plant roots can cause issues, think of trees and sidewalks Also called mechanical weathering

Enchanted Rock - Exfoliation

High Plains Water Erosion Wind Erosion Deposition

Gulf Coast Plains and Marshes

Chemical Weathering Oxidation – reaction with oxygen makes a new chemical compound Eventually causes the rocks to break apart as the old chemical bonds get broken that were holding the rock together.

Acid Precipitation From pollution Can be from natural events or man made Makes the rain more acidic than normal and it dissolves rock, especially limestone and marble Most of the buildings are made of limestone and marble.

Erosion and Deposition They work together to change the face of the Earth Erosion breaks up the rocks, soil, and sediment and move it away Deposition lays it down somewhere else Caused by water, wind and gravity How does that affect a shore?

Erosion and Deposition

Our Effect on the High Plains Dust Bowl Happened in the 1930’s during the Great Depression In southeastern Colorado, southwest Kansas and the panhandles of Oklahoma and Texas

Dust Bowl - Causes Farmers tore the buffalo grass up to make way for plowed fields A severe drought hit the area and the crops did not grow, leaving the soil exposed. The weather became very windy picking up the soil and blowing it in the air.

Dust Bowl A giant dust storm blacks out the sky of Goodwell, Okla., during the Dust Bowl.

Dust Bowl By 1934, it was estimated that 100 million acres of farmland had lost all or most of the topsoil to the winds. By April 1935, there had been weeks of dust storms, but the cloud that appeared on the horizon that Sunday was the worst Dust from this storm fell in New York City.

Dust Bowl

Dust Bowl In 1941 rain poured down on the region, dust storms ceased, crops thrived, economic prosperity returned, and the Dust Bowl was over.

Dust Bowl Effects extended severe drought and unusually high temperatures episodic regional dust storms and routine localized wind erosion agricultural failure, including both cropland and livestock operations the collapse of the rural economy, affecting farmers, rural businesses, and local governments an aggressive reform movement by the federal government migration from rural to urban areas and out of the region