Weathering is the physical and chemical breaking down of rocks (the lithosphere) into smaller pieces or particles by wind, water, ice, plants, animals, people, or chemical change.

Types of Weathering 1) Physical Weathering 2) Chemical Weathering the physical breaking of rocks into smaller pieces. The size of the rock changes, not its composition. 2) Chemical Weathering the change in mineral composition, or chemical make-up, of a rock. The composition changes, which may affect the size of the rock.

Temperature Change & Exfoliation Physical Weathering Frost Wedging Root Pry Organic Activity Temperature Change & Exfoliation Abrasion Gravity

Frost Wedging occurs when water freezes in the cracks of rocks causing the rocks to break.

Root Pry or Plant Rooting occurs when plant or tree roots grow within or between rocks causing the rocks to break.

Organic Activity and/or Biological Activity which is the wildlife that affects the size of rocks and the soil surrounding these rocks by digging and scraping against the rocks.

Temperature Change and Exfoliation occurs when temperatures change causing a constant expansion and contraction of rock. The rock begins to flake or peel.

Abrasion occurs when rocks and soil scrape against other rocks causing these rocks to break into smaller pieces. An example is a rockslide.

Gravity affects weathering when the gravitational pull forces soil and rocks down mountains, hills, streams, rivers, etc.

Plant Acids or Humic Acids Chemical Weathering Oxidation Carbonation Plant Acids or Humic Acids Hydration

Oxidation occurs when oxygen is combined with another substance causing a chemical change, usually rust.

Carbonation occurs when carbon dioxide dissolves in water causing an acid rain to form. The acid rain reacts with rocks causing a chemical change.

Hydration occurs when rocks lie in water for long periods of time causing a chemical change in composition.

Plant Acids or Humic Acids cause weathering when acids from mosses and lichens break down the minerals found in rocks.