Soils, Weathering, and Erosion: Formation, Properties, and Issues, Slides of Geology

Download Soils, Weathering, and Erosion: Formation, Properties, and Issues and more Slides Geology in PDF only on Docsity! 1 Chapter 6 Soils, Weathering, and Erosion Soil The thin layer of weathered bedrock and organic material that supports plant life—but we also call “dirt” or detritus “soil” Environmental Factors of Soil Formation Climate Organic Activity Topographic Relief & aspect Parent Material Time Soil forms from the weathering of regolith Weathering Physical and chemical breakdown of bedrock and regolith Physical weathering caused by temperature changes and disruption by plants and animals Chemical weathering include solution, oxydation, hydration, and hydrolysis Modes of Physical Weathering Water freezes (9% expansion) Salt crystals form (expansion) Insolation (heating of the sun) Unloading Root wedging Rate of Weathering Depends on mineral composition of regolith, surface area, and climate Smaller particles weather faster than large masses Iron-rich minerals weather faster than quartz or feldspar Docsity.com 2 Features and Landforms Spheroidal Weathering Exfoliation Domes Soil Profile Distinguishable layers, or horizons in mature soils Organic-rich O horizon A horizon zone of leaching B horizon zone of accumulation C horizon of weathered parent material Climate influences thickness of horizons and the rate of soil formation Residual Soil Developed in place on underlying rock Also known as saprolite Oxisols Laterites Transported Soil Developed on regolith and deposited by wind, glaciers, rivers, or volcanic action Loess Soil Classification Classification of soil into 11 orders by their physical characteristics that reflect soil age and climate Soil Type Distribution Docsity.com