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-on- the-Lake, Ontario, Canada Root Action Burns 2007

-- 3) Exfoliation: --

Exfoliation caused by: Thermal expansion –-- –Very common in arid areas like Southwest U.S.

Geology 211, Physical Geology, ©, 2002, Ron Parker Thermal Expansion

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 H 2 O (rain) + CO 2 (carbon dioxide) = H 2 CO 3 (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

Stalagmites Stalactites

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, FloridaSinkhole 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. formed catastrophically

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?