Chalk. When tiny organisms living in shallow seas die and sink to the bottom, their skeletons join together to make chalk.

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Size: 4700px × 3836px
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Photo credit: © World History Archive / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: archival, archive, bottom, chalk, chalk., die, geology, historical, history, join, living, mineralogy, organisms, seas, shallow, sink, skeletons, tiny