Transcript Weathering
Topic Physical and Chemical Weathering Weathering vs. Erosion Weathering -Erosion -- Physical (Mechanical) Weathering -- 1) Frost Action Temperature drops below freezing •-•-- Expanding ice causes crack to become larger Frost Action Frost Action Causes Roadway Potholes No, it’s the L.I.E. Potholes & Frost Heaves 2) Organic Activity: -- Plant roots create a channel for air and water to go into the rock Niagara Glen, Niagara-onthe-Lake, Ontario, Canada Root Action Burns 2007 3) Exfoliation: -- Exfoliation caused by: Thermal expansion – -– Very common in arid areas like Southwest U.S. Thermal Expansion Geology 211, Physical Geology, ©, 2002, Ron Parker Physical changes in sediments Abrasion: -- Formed by water abrasion Formed by wind abrasion Final Question: Name a location on Earth that has a considerable amount of frost action. Topic: Chemical Weathering Chemical Weathering -- **--** Solution - -Ex) Salt dissolving in water Soluble – -Ex) Salt is soluble in water Powerful Solutions: Acid Rain H2O (rain) + CO2 (carbon dioxide) = H2CO3 (carbonic acid) Result: *-*-- The details of marble statues and tombstones will be gradually worn away by dissolution. Image courtesy of Dr. Annabelle Foos. Karsts Topography – forms caves, caverns, and sinkholes Stalactites Stalagmites The Witch's Finger, a stalagmite in the Carlsbad Caverns, NM NPS photo by Peter Jones Do you see the person in this picture? Sinkhole Formation Sinkhole—Winter Park, FL Sinkhole at Winter Park, Florida (1981) that formed catastrophically in the time span of one day. The city of Winter Park stabilized and sealed the sinkhole, converting it into an urban lake. 2) Create Plant Acid -- => -- -- Hydration •-- => Oxidation – -Ex) Iron + Oxygen = Iron Oxide (rust) Rust – Oxidation of Iron Oxidation of Copper FQ: What rock dissolves to form stalactites in a cave?