4th week of notes
4th week of notes GEOL 105 ( Ken Lepper)
Popular in Physical Geology
Popular in Geology
This 3 page Class Notes was uploaded by Luis Blanco Seguerit on Saturday September 19, 2015. The Class Notes belongs to GEOL 105 ( Ken Lepper) at North Dakota State University taught by Ken Lepper in Fall 2015. Since its upload, it has received 106 views. For similar materials see Physical Geology in Geology at North Dakota State University.
Reviews for 4th week of notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/19/15
GEOL 105 Ken Lepper NoteTaker 091815 Weathering o Weathering the physical breakdown disintegration and chemical alteration dissolutiondescom positionof rock at Earth s surface 0 twotypes of weathering 0 Physical Weathering I Breaking of rocks into smaller pieces by mechanical processes 0 Chemical Weathering I breaking down of rock components and internal structures of minerals by chemical processes 0 Positive feedback cycle between physical and chemical weathering Physical I Mechanical Weathering 0 Types of physical weathering mechanical processes 0 Thermal expansion contraction o Wetting and drying 0 Frost wedging I water increases in volume 9 when it transform from liquid to solid 0 Unloading Exfoliation Sheeting I Exfoliation is called sheeting fractures sometimes 0 Biological Activity Biophysical weathering I Plants have a remarkable ability to grow through small cracks Examples Desert Cobble thermal expansioncontraction Wetting and drying of shale slaking Chemical Weathering o Aqueous Processes o Dissolution I Aided by small amounts of acid in the water I Best example is rain water and limestone 0 Ion Exchange I Chemical exchange of ions in solution with sedimentsoil usually clay particles 0 Oxidation I Any reaction in which electrons are lost from an element I Frequently involves production of oxide minerals Examples Dissolution Graves Oxidation Rust Metallic FeO 3e Fe3 Fe203 Hematite 0 Biochemical Processes 0 Weak organic Acids I Many biological waste products are weak acids I some organisms secrete acid intentionally to release nutrients from rocks Example Lichens Biochemical weathering agents Effects of Weathering o Alterations caused by chemical weathering o Decomposition of soluble minerals ions in solution 0 Formation or retention of stable materials 0 Smoothing or rounding of corners and edges Erosion o Erosion the physical transportation of material by ibile agents such as water wind ice or gravity 0 Particulates Sediments o Solutes dissolved ions o The mobile Agents ErosionITransportI depositional systems water Fluvial rivers and streams Wind Eolian Ice Glacial Gravity Mass wasting 0000 Soil is a combination of the 4 things Atmosphere Lithosphere hydrosphere and Biosphere Soil 0 Soil combination of minerals organic matter water and air that supports the growth of plants 0 Regolith rock and mineral fragments produced by weathering o Humus decaying animal and plant remains 0 Living Organism and their biotic processes are also an essential component of soils The Ideal Soil Compositio in this case ideal for Crop Production Soil the ultimate biofilm that sustains life on lands Active soil layer average thickness gt 1 meter The Type and quality of soils depends on 0 Five Soil Forming Factors 0 Parent Material I Ex residualregolith vs transported soil 0 Topography I Exhill top vs valley bottom 0 Climate I key factors temperature amp precipitation o Organism I influence the soil s physical chemical properties 0 Time I Amount of time for soil formation varies for different soils depending on geologic and climatic conditions Water L I Mineral 25 Solids 45 g VA Soil Ease E fr39 39 u re Space Drgnic 5 The Soil Profile 0 Soil forming processes operate from the surface downward 0 Vertical differences the layers are called soil horizons 0 Master horizons o O horizon organic matter 0 A horizon organic and mineral matter I High biological Activity I O and A horizons make up the Topsoil o E horizon little organic matter I Zone of leaching o B horizon zone of accumulation o C horizon partially altered parent material Collectively the O A E and B horizons Solum or true soilquot End of week