Friday Rock Blogging: Hypertufa
Most geologists are familiar with tufa, which is a type of calcium carbonate. Tufa is precipitated from calcium-rich water in low-energy environments (lakes, ocean-bottom sediments, etc.) – and if you’re anywhere near California, it’s worth driving up to Mono Lake to check out the fabulous tufa towers.
Hypertufa is similar to tufa, but it’s precipitated from high-energy environments, like mountain streams and rocky intertidal zones. In such a turbulent depositional setting, grains of sand and silt, along with miscellaneous bits of debris, are often mixed in with the carbonate deposits.
[Update, April 2: Why yes, this was an April Fool. No, it wasn’t a tremendously funny one. Hush, you. Anyway, hypertufa is a popular type of fake rock made from peat, perlite, and Portland cement.]