Triassic Water

Glossary

Limestone

Limestone is rock made mostly of calcium carbonate, and it formed from the shells of animals that lived in the sea.

What the glossary says

Limestone — “a sedimentary rock, chiefly composed of calcium carbonate; formed from the shells of marine animals”

U.S. Geological Survey, “Glossary of Geologic and Architectural Terms”. Quoted word for word. Credit: U.S. Geological Survey.

A tall pale limestone pillar rising out of flat prairie grassland, lit by a pink and orange sunrise sky.
Real photographCastle Rock, a limestone pillar standing above the prairie of western Kansas near Quinter, in Gove County, at sunrise.marekuliasz/Shutterstock.com · Shutterstock Standard License · Licence record

Where this word appears on Triassic Water

Every word in the glossary

Sources

The definition
U.S. Geological Survey, “Glossary of Geologic and Architectural Terms”, dated 07.21.97 on the page itself, https://pubs.usgs.gov/gip/acidrain/glossary.html, read . A work of the U.S. Government, in the public domain. Credit: U.S. Geological Survey.
How this page is made
The definition is quoted exactly. The one plain sentence under the word is ours, and it may not add a number, a date, a place or a living thing the definition does not already name. The picture carries its own credit.