1 / 11

Understanding Weathering: Processes and Factors Affecting Rock Breakdown

Weathering is the process by which rocks break down on Earth’s surface through mechanical and chemical actions. Factors such as temperature, pressure, and agents like water and acids influence the rate of weathering. This text explores how rock type, composition, and surface area impact the weathering process. Learn about mechanical breakdown, chemical reactions, and the role of climate in accelerating weathering.

quach
Download Presentation

Understanding Weathering: Processes and Factors Affecting Rock Breakdown

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ch. 7 Sec. 1 Weathering

  2. Weathering • Weathering • Process by which rocks on or near Earth’s surface break down and change • Erosion • Removal and transport of weathered material

  3. Mechanical Weathering • Physical breakdown (size, shape) of rock • Temperature • Expanding and Freezing of water in cracks: Frost Wedging

  4. Mechanical Weathering • Physical breakdown • Pressure • The pressure is causing outer rock layers to be stripped away: Exfoliation

  5. Chemical Weathering • Changes in the Composition of the rock • Agents of chemical weathering…. • Water, oxygen, carbon dioxide, and acids • Temperature influences the rate of chemical weathering • Water • Dissolves many minerals • Hydrolysis: decomposition of silicate minerals

  6. Chemical Weathering • Oxygen • Oxidation: chemical reaction of oxygen with other substances • Abundant in the atmosphere • Iron in some rocks can react forming new rocks • Pyrite • Magnitite

  7. Chemical Weathering • Carbon dioxide (CO2) • Produced by living organisms respiration • CO2 with water produces carbonic acid • The process of the carbonic acid reacting with minerals results in the formation of clay minerals

  8. Chemical Weathering • Acid Precipitation • From burning of fossil fuels • Forms Sulfuric and Nitric acids • Describe the solutions by the pH scale. The lower the number, the more acidic

  9. Rate of Weathering • Rate of weathering occurs slowly, but some interactions can accelerate the process • Climate  affects both chemical and physical • Chemical weathering (high) • Precipitation, temperature, & evaporation • High temps and rainfall speed up chemical weathering • Physical weathering • Cool and dry conditions (water freezes and thaws)

  10. Rate of Weathering • Rock Type and Composition • Hardness and surface area helps decrease weathering • Sedimentary rocks weather more easily than igneous and metamorphic

  11. Rate of Weathering • Surface Area • Mechanical weathering breaks up rocks into smaller pieces • As pieces get smaller, their surface area increases • And surface area increases, the more weathering occurs

More Related