How Does Calcareous Ooze Form?

calcareous-ooze-form Credit: James St. John/CC-BY-2.0

Calcareous ooze forms as the skeletal remains from specific microscopic sea organisms settle to the ocean floor. The skeletons and shells that form calcareous ooze are made of calcium carbonate. Other types of ooze are made from skeletons that are comprised of other elements.

Calcareous ooze is the most plentiful of oozes on the ocean floor, covering some 50 million square miles of seabed. It can be found at distances greater than 100 miles offshore and at depths of less than 14,800 feet. It is not found closer to land because here sediments from the shore are constantly altering the seabed.

There are two types of calcareous ooze: globigerina and pteropod. These classifications are given according to the dominating remains found in the ooze. Globigerina ooze is composed mainly of planktonic foraminifera shells and is one of the most widespread of the oozes in the Atlantic and Indian oceans. Pteropod ooze has a dominating presence of deep sea mollusk shells but can only be found in the mid-Atlantic. Calcareous ooze is found in greater quantities in mid-latitude areas due to a more plentiful supply of contributing organisms in warmer waters.

The composition of Calcareous ooze is usually very similar to limestone; however, sometimes it is nearly pure calcium carbonate. Calcium carbonate has may uses from construction to dietary supplements to the treatment of acid reflux. Even the famous White Cliffs of Dover in England are calcium carbonate that was once calcareous ooze at the bottom of the ocean 66 million or more years ago.