On the waves. (Letters)."Waves," or crenulations, occur not only on water icicles ("Icicle waves go with the flow," SN: 12/14/02, p. 381), but also in caves on dripstone dripstone: see stalactite and stalagmite. and flowstone flow·stone n. A layered deposit of calcium carbonate on rock where water has flowed or dripped, as on the walls of a cave. speleothems composed of calcite calcite (kăl`sīt), very widely distributed mineral, commonly white or colorless, but appearing in a great variety of colors owing to impurities. , epsomite, goethite goethite Widespread iron hydroxide mineral, α-FeO(OH), the most common ingredient of iron rust. In terms of relative abundance, it is second only to hematite (α-Fe2O3) among iron oxides. , and even mud. All of these formations display "wavelengths" of around 1 centimeter. The origin of these crenulations is due not to heat, but to greater evaporation and carbon dioxide loss from thin liquid-water films flowing over slight surface protrusions. CAROL A. HILL, ALBUQUERQUE, N.M. |
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