Chert: Modern Inorganic Deposition in a Carbonate-Precipitating Locality

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Science  24 Sep 1965:
Vol. 149, Issue 3691, pp. 1501-1503
DOI: 10.1126/science.149.3691.1501


Chert is precipitating as gelatinous opal-cristobalite in lakes associated with the Coorong Lagoon of South Australia. Dolomite, magnesite, and magnesian calcite are also being deposited. High pH (9.5 to 10.2) causes dissolution of detrital silicates; lowering of pH (7.0 to 6.5) and drying of the lakes cause precipitation of chert. time.