GEOG1710 1st Edition Lecture 18 Outline of Previous Lecture I Steam Energy II Fluvial Erosion III Fluvial Transport IV Fluvial Deposition V Arid landscapes VI Arid Environment Outline of Current Lecture I II III IV V Basin and Range Terrain Mesa and Scarp Terrain Badlands Aeolian Processes Dust Current Lecture Basin and Range Terrain 1 2 3 Most of US Southwest interior Adjacent N S mountains and flat valley floors Formed by crustal thinning continental rifting Alluvial fan streams from basin and range dump out sediments to flat areas after basin usually where farming occurs Mesa and Scarp Terrain Formed from uplift and then down cutting of water Top is mesa where it is flat It is formed by o Horizontal sedimentary rock layers o Resistant to erosion creates steep slope angles o These layers from the mesa flat topped steep sided hill o And the scarp more less vertical clif Badlands These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Weak easily eroded rock Formed by erosion from overland flow Rugged barren highly dissected terrain Aeolian Processes Aeolus the Greek God of Wind Eolian or Aeolian relating to or arising from the action of wind Aeolian process is important where sparse vegetation dry loose mat and wind which to erosion transportation and deposition Process 1 Erosion o Deflation removal and lifting of individual loose particles Desert pavement surface covered with closely packed rock fragments of pebble and cobble size o Abrasion grinding of rock surfaces by sandblasting action of particles captured in air Process 2 Transportation o Most that can be suspended in air is sand size particles o Heavier saltation is jumping along creep is pushed along Leos Deposits deposits of windblown sediment Dust Fine particulate material that is removed from land surface by wind erosion and is small enough to be suspended in the atmosphere Factors that afect wind erosion o Vegetation slows wind and reduce erosion while roots hold soil in place o Soil moisture wind can t erode moist soil because of surface tension o Structure of surface organic matter reduces erosion o State of the soil surface desert pavement strongly inhibits erosion Grasslands are a direct response to the dust bowl Dust efects o Climate radiation budget o Particles absorb and reflect incoming solar radiation o Some particles cool the atmosphere while others warm it up o Dust deposition onto ecosystems o Dust on snow problem o Human health o Hazards visibility roads etc
View Full Document
Unlocking...