Weathering 1/4/ a pgs IN: How does sediment form? Glue in the new Table of Contents
Weathering - the breakdown of rock into smaller and smaller pieces.
Mechanical Chemical Types of Weathering
Mechanical Weathering - the breakdown of rock by physical means. –Ice –Wind –Water –Gravity –Plants –Animals –Humans
When water seeps into a crack in a rock and freezes it expands. When it expands, it pushes against the sides of the crack, forcing it to open wider. Ice Wedging
An enormous mass of moving ice. Glaciers
Abrasion - the action of rocks and sediment grinding against each other and wearing away exposed surfaces. Wind and Water
Valley of Fire State Park
River rocks Sandblasting Rocks tumbling down a mountainside
Like ice wedging –Plants get into smaller cracks and as they grow they split the rock apart.
Burrowing Worms Chemical Weathering
OUT: Describe one type of mechanical weathering.
Chemical Weathering 1/5/ b pgs IN: Describe the similarity between the ways tree roots and ice mechanically weather rock.
When water seeps into a crack in a rock and freezes it expands. When it expands, it pushes against the sides of the crack, forcing it to open wider. Ice Wedging
Like ice wedging –Plants get into smaller cracks and as they grow they split the rock apart.
Chemical Weathering - the chemical breakdown of rocks and minerals into new substances. –Water –Weak acids –Air –Soil
Water causes many things to dissolve. –Even hard rock, like granite, is broken down by water.
Acid rain is caused due to pollution. Can cause very rapid weathering of rock.
Breaks down limestone found underground –Forms caves
Lichens produce organic acids that can slowly break down rock.
Oxidation - a chemical reaction in which an element, such as iron, combines with oxygen to form an oxide. Fe + O FeO ironoxygenIron oxide
Water speeds up this process. –rust
Red Rock Canyon
Mars
OUT: Why does acid precipitation weather rocks faster than normal precipitation does?