Topic: Chemical Weathering

Breakdown of rock

by changing the

chemical

composition.

**Water is the #1 agent of chemical weathering.**

Solute- substance dissolving in a

liquid

Ex) Salt dissolving in water

Soluble – able to dissolve in a fluid

Ex) Salt is soluble in water

Powerful Solutions:

Acid Rain H2O (rain) + CO2 (carbon dioxide) = H2CO3 (carbonic acid)

Result:

*Dissolves limestone, calcite, and marble rock

*Underground cave systems

The details of marble statues and

tombstones will be gradually worn

away by dissolution. Image courtesy of Dr. Annabelle Foos.

Karst Topography –

forms caves,

caverns, and

sinkholes

http://www.youtube.

com/watch?v=0rFg

XghKH9U

Stalagmites

Stalactites

Stalactites Crystal Ball Cave

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.

Sinkhole Tour in Florida by CNN

http://abcnews.go.com/WNT/video/sinkhole-strike-back-26846775

Create Plant Acid

Damp roots secrete carbon dioxide => carbonic acid

Chemical weathering occurs in warm,

humid climates

Hydration

=>

Water combines with elements making

rock weaker

Oxidation –

Elements reacting with Oxygen

Ex) Iron + Oxygen = Iron Oxide (rust)

Rust – Oxidation of Iron

Oxidation

of Copper

FQ:

What rock dissolves to form stalactites in a cave?