Editing Flowstone (section)

{{Short description|Geological phenomenon}}
{{more footnotes|date=December 2013}}
[[File:Saracen's Tent, Luray Caverns.jpg|thumb|''Saracen's tent'' in [[Luray Caverns]] in [[Virginia]] is considered to be one of the most well-formed flowstone draperies in the world]]

'''Flowstones''' are sheetlike deposits of [[calcite]] or other carbonate minerals, formed where water flows down the walls or along the floors of a [[cave]].<ref>Hill, C A, and Forti, P, (1997). Cave Minerals of the World,  (2nd edition). [Huntsville, Alabama: National Speleological Society Inc.] p.70</ref> They are typically found in "solution caves", in [[limestone]], where they are the most common [[speleothem]]. However, they may form in any type of cave where water enters that has picked up dissolved minerals. Flowstones are formed via the degassing of [[vadose]] percolation waters.<ref name=Drysdale>{{cite journal |doi=10.1130/G22103.1 |title=Late Holocene drought responsible for the collapse of Old World civilizations is recorded in an Italian cave flowstone |year=2006 |last1=Drysdale |first1=Russell |last2=Zanchetta |first2=Giovanni |last3=Hellstrom |first3=John |last4=Maas |first4=Roland |last5=Fallick |first5=Anthony |last6=Pickett |first6=Matthew |last7=Cartwright |first7=Ian |last8=Piccini |first8=Leonardo |journal=Geology |volume=34 |issue=2 |pages=101|bibcode=2006Geo....34..101D }}</ref>

Flowstone may also form on manmade structures as a result of calcium hydroxide being leached from  concrete, lime or mortar. These secondary deposits created outside the cave environment, which mimic the shapes and forms of speleothems, are classified as "[[calthemite]]s" and are associated with [[concrete degradation]].<ref name=smith2016>Smith, G.K., (2016). “Calcite Straw Stalactites Growing From Concrete Structures”, Cave and Karst Science, Vol.43, No.1, P.4-10, (April 2016), British Cave Research Association, ISSN 1356-191X.</ref>