Chp 10.2 Notes Groundwater Erosion & Deposition

MAIN IDEA: LANDFORMS CAUSED BY THE CHEMICAL

WEATHERING OF LIMESTONE ARE CALLED

KARST TOPOGRAPHY.

Chp 10.2 NotesGroundwater

Erosion & Deposition

Two Requirements for Karst Topography!

ACIDIC WATER IS FORMED BY a CARBONATION PROCESS:

Describe: Water drips down through soil and reacts with carbon dioxide. This creates carbonic acid, a relatively weak acid.

ACIDIC RAIN WATER

Limestone (Rock) +

When the two meet

Action:Carbonic acid dissolves limestone slowly, over a long period of time.

The Structures formed

LIMESTONE PAVEMENTDescribe:An area of limestone that has been chiseled away and is exposed at earth surface

Shallow hole

Describe:A hole that forms and “swallows” a stream as underground limestone is dissolved

Sinkhole (hint: Avoid Limestone regions!!)

Describe:Rainfall in the soil absorbs carbon dioxide & reacts with decaying vegetation, creating acidic water. Acidic water moves through spaces underground, SLOWLY dissolving limestone, creating cavities. Cavities gradually get enlarged & carry even more acidic water. Sinkholes formed when the land surface above finally collapses by gravity & then sinks into the cavities.

Caves/caverns

Stalactites (“don’t fall, hang on tite!”)

Describe: Hollow, elongated forms of various

minerals deposited from solution by slowly dripping water. They hang from a cave ceiling.

Stalagmites

Describe: Cones or massive mounds of calcite deposits that grow up from a cave floor due

to dripping water.

Speleothems

Describe: Known as “decorative cave formations”. Threads of deposited minerals that hang from a cave ceiling and sprout from a cave floor as a result of dripping water.