Weathering

Weathering is the breaking down of rocks and other materials on the earth’s surface

In other words, Weathering is when rocks are broken into soil, sand, and sediment (tiny pieces or particles).

Weathering involves two processes that often work together to decompose or break down rocks.

What are 2 Types of Weathering?

Chemical & Mechanical Weathering

What is the difference??? Chemical weathering is where the substance completely changes Mechanical weathering is where it is the same thing-it physically changes

Mechanical weathering, or disintegration, involves physically breaking rocks into bits without changing the chemical make-up of the minerals. (No change in the rock’s chemical composition.)

Wind as an agent of Weathering  Wind can carry away bits of rock and sand.  It also can chip away at rock surfaces.  Sand dunes are formed when wind blows sand against something such as a plant or rock.  Wind erosion also forms tables, arches and columns.

This red sandstone arch started out as a vertical slab of rock, that was worn through (over a very long time) by the action of wind, sand, and abrasion.

Abrasion Both wind and water can cause abrasion (a wearing, grinding, or rubbing away) as rock fragments bounce off each other.

These rocks have been blasted by wind and sand causing them to become rounded. WIND ABRASION

columns

Sand table

Grass has stabilized this sand dune on Gulf Islands National Seashore, Florida.

This sand formed a pedestal where these plants can survive (after the dune where they first grew blew away).

Aerial view of Jockey’s Ridge, NC

Reading About Wind Read about how wind can change and create landforms on page C8. Discuss the question with your neighbor.