Microscopic organisms of the group protozoa that are found living mainly in marine environments. These organisms produce shells rich in calcium carbonate. Sedimentation and lithification of these shells produces the sedimentary rock chalk. Found on http://www.physicalgeography.net/physgeoglos/f.html
Microscopic organisms of the group protozoa that are found living mainly in marine environments. These organisms produce shells rich in calcium carbonate. Sedimentation and lithification of these shells produces the sedimentary rock chalk.