Exogenic Process: How Weathering Shapes the Planet

This presentation discusses the process of weathering. This includes the different types of weathering and the way weathering shapes the planet.

1. Weathering: The Shaping Force of Earth Weathering is the process that breaks down rocks, soils, and minerals through direct contact with the Earth's atmosphere, biota, and waters. by MICHAEL DENIEGA

2. Mechanical Weathering 1 Frost Wedging Water freezes in cracks, expands, and widens the fissures, gradually breaking down rocks. 2 Thermal Stress Rapid temperature changes cause rocks to expand and contract, leading to fracturing and eventual disintegration. 3 Salt Wedging Salt crystals grow in rock pores, exerting pressure that causes the rock to break apart. 4 Abrasion Rocks are ground down by the friction of moving particles like windblown sand or waterborne sediment.

3. Chemical Weathering Dissolution Rocks are dissolved by acidic water, such as rainwater that has absorbed carbon dioxide from the atmosphere. Oxidation Iron in rocks reacts with oxygen, forming iron oxide (rust) and weakening the rock structure. Hydrolysis Water reacts with minerals in rocks, breaking them down into new compounds, such as clay. Carbonation Carbon dioxide dissolves in water to form carbonic acid, which reacts with calcium carbonate in rocks, leading to dissolution.

4. Biological Weathering 1 Plants Plant roots grow into cracks, expanding and breaking rocks apart. 2 Animals Burrowing animals like earthworms and moles create tunnels that expose rocks to weathering. 3 Lichens Lichens produce acids that chemically weather rocks, creating a substrate for their growth. 4 Bacteria Bacteria break down organic matter and release acids that can contribute to chemical weathering. orientation=vertical twosided=false

5. Factors Affecting Weathering Climate Temperature, rainfall, and freeze-thaw cycles influence weathering rates. Rock Type Different rocks have varying resistance to weathering based on their mineral composition and structure. Topography Slope, elevation, and exposure to sunlight affect weathering rates.

6. Weathering and Erosion Weathering Breaks down rocks into smaller fragments. Erosion Transports weathered material by wind, water, or ice. Deposition Weathered material is deposited in new locations, shaping landscapes. orientation=horizontal

7. Weathering Processes in Different Climates Climate Dominant Weathering Processes Arid Physical weathering, such as abrasion by wind and salt wedging. Tropical Chemical weathering, due to high temperatures and humidity. Glacial Physical weathering, caused by the grinding action of ice. Coastal Physical weathering, from wave action and salt spray.

8. Weathering and Soil Formation Parent Material Weathered rock fragments provide the foundation for soil. Organic Matter Decomposed plant and animal remains enrich the soil. Water Rainfall and groundwater influence soil development and nutrient transport. Climate Temperature, rainfall, and other climatic factors shape soil properties.

9. Weathering and Rock Cycle 1 Weathering Breaks down rocks into smaller fragments. 2 Erosion and Transportation Weathered material is moved by wind, water, or ice. 3 Deposition Weathered material is deposited in new locations. 4 Lithification Sediments are compacted and cemented to form sedimentary rocks. 5 Metamorphism Heat and pressure transform sedimentary rocks into metamorphic rocks. 6 Melting and Cooling Metamorphic rocks melt and cool to form igneous rocks. orientation=vertical twosided=false

10. Importance of Understanding Weathering Weathering plays a critical role in shaping the Earth's surface, influencing soil formation, geological processes, and human activities.