Editing Limestone (section)

====Other descriptive terms====
[[File:Chalk ("Upper Chalk" Formation, Upper Cretaceous; White Cliffs of Dover, England, southern Britain).jpg|thumb|Chalk from the White Cliffs of Dover ([[Chalk Group]]), England]]
''[[Travertine]]'' is a term applied to calcium carbonate deposits formed in freshwater environments, particularly [[waterfall]]s, cascades and [[hot springs]]. Such deposits are typically massive, dense, and banded. When the deposits are highly porous, so that they have a spongelike texture, they are typically described as ''[[tufa]]''. Secondary calcite deposited by [[Supersaturation|supersaturated]] [[meteoric water]]s ([[groundwater]]) in caves is also sometimes described as travertine. This produces [[speleothem]]s, such as [[stalagmite]]s and [[stalactite]]s.{{sfn|Blatt|Middleton|Murray|1980|p=479–480}}

''[[Coquina]]'' is a poorly consolidated limestone composed of abraded pieces of [[coral]], [[Exoskeleton|shells]], or other fossil debris. When better consolidated, it is described as ''coquinite''.{{sfn|Boggs|2006|p=172}}

''[[Chalk]]'' is a soft, earthy, fine-textured limestone composed of the tests of planktonic microorganisms such as foraminifera, while
''[[marl]]'' is an earthy mixture of carbonates and silicate sediments.{{sfn|Boggs|2006|p=172}}
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