Discovery Formations Map

The Cave

Speleothem. Speleo-what?

Speleothem is greek for “cave deposit”, or cave formation. Marengo Cave is blessed with a wide variety of speleothems.

Soda Straws

Soda straws form when slow seeping water enters through a cave's ceiling. Tiny circular rings of calcite are deposited one after another, forming a straw.

Stalactites

Stalactites, a most common cave formation, begin life as soda straws that become clogged. They grow downward until touching the cave floor.

Stalagmites

Stalagmites are formed by water dripping from the ceiling. When the drop lands, calcite is deposited and a stalagmite grows upward.

Flowstone

As water entering the cave flows down walls and over floors or breakdown, calcite is deposited in deeper and deeper layers. This is known as Flowstone.

Draperies

When water entering a cave flows down a sloping ceiling, it deposits calcite in thin, translucent sheets that hang in delicate folds like draperies. Minerals provide color.

Helictites

Helictites are small, twisted formations that project from cave ceilings, walls, and even the floor. They grow erratically and defy the laws of gravity.

Cave Popcorn

Also called cave coral, this formation can be found in many sizes, shapes, and colors. Most common are the small, knobby clusters that resemble popcorn.

Rimstone Dams

Rimstone dams are formed as water flows and tumbles over an edge, like water overflowing a sink. This results in calcite deposits around the edge of the dam.