Stalagmites and Stalactites Katie Winter Geology 1010

What are they? Stalagmites and Stalactites are conical deposits that are formed in caves. Stalagmites are formed from the floor up while Stalactites form from the ceiling.

Composition of Stalagmites They are a kind of speleothem, or cave formation. It is composed of the deposition of calcium carbonate from the dripping of minerals and limestone of the stalactite.

Composition of Stalactites Stalactites are also made out of calcium carbonate but are formed when the ceiling is wet and drips down the minerals at an edge. It is called a dripstone.

Where are they found? They are found mostly in limestone caves. They can also be found in lava tubes. Stalactites can be formed on concrete when there is a leak in the water pluming that releases limestone minerals.

Lava Tube Stalagmite

How old are they? Stalactites from between one quarter of an inch and an inch per century. They can also be dated by radioactive isotopes.

Stalagmites Stalagmites are built up from many successive growth layers. Each of these layers are made up of tiny calcite crystals layered almost perpendicular to the growing surface below.

Stalagmites cont. The shape of a stalagmite can be tall like broomsticks, short, or have multi tiered towers. Each shape is determined by the drip rate, ceiling height, and atmospheric conditions.

Multi tiered Stalagmite

Stalactites Soda straws represent the earliest growth of a stalactite. They are hollow, elongated tubes of calcite. Drops on a soda straw lose carbon dioxide before falling to the ground and so precipitate some of the calcium carbonate they carry and is added to thin blades of calcite to create the tips of the soda straw.

Stalactites cont. The soda straws can be affected by moving wind or moving water. Evaporation causes the growth of crystals from the solution impurities being mixed in the calcite. They can reach up to 30 feet.

Soda Straws

Examples: Timpanogos Cave

Bath

Bibliography http://geography.about.com/library/faq/blqztite.htm http://en.wikipedia.org/wiki/Stalagmite http://en.wikipedia.org/wiki/Stalactite http://science.howstuffworks.com/environmental/earth/geology/stalactite- stalagmite1.htm http://www.goodearthgraphics.com/virtcave/stalmite/stalmite.html http://www.goodearthgraphics.com/virtcave/staltite/staltite.html