Weathering

Weathering – breaking down rocks into smaller pieces. Assist in soil formation 2 forms of Weathering 1. Mechanical – physically breaking rocks into smaller pieces 2. Chemical – rock is broken down by a chemical process

Ex. Of Mechanical Frost wedging – freezing and thawing of rocks prying rock apart Abrasion – when rocks scrape or grind against each other Biological activity – plant roots pry the rock apart, worms, moles, etc.

Chemical Weathering The main agent involved is water Water assists in oxidation, and carbonic acid (Acid rain) Dissolution – dissolves with water present Rust oxidizes with water

Rates of Weathering Depends on 3 main factors: Climate – high temp increase chemical weathering Water – Increases the rate of weathering Mechanical weathering is faster where there is a lot of freezing and thawing Composition of Material – some rocks are more resistant to weathering Limestone and marble easily weather Slate doesn’t Surface area – increase the exposed surface are increases weathering