The Quarterly journal of the Geological Society of London . Limestone wasperhaps a stage in the same direction; the Upper Greensandat Ventnor was converted in a similar way into chert, and thePortland oolite was locally converted into chert. It would beinteresting to know whether the process now described was by trans-ference of silica from organisms, or was from thermal springs, aswas probably the case in the Stotfield sandstone near Elgin. Prof. Watts said that he had observed several cases of thegrowth of quartz-crystals in limestone, though the process hadnever gone quite so far as the ext
The Quarterly journal of the Geological Society of London . Limestone wasperhaps a stage in the same direction; the Upper Greensandat Ventnor was converted in a similar way into chert, and thePortland oolite was locally converted into chert. It would beinteresting to know whether the process now described was by trans-ference of silica from organisms, or was from thermal springs, aswas probably the case in the Stotfield sandstone near Elgin. Prof. Watts said that he had observed several cases of thegrowth of quartz-crystals in limestone, though the process hadnever gone quite so far as the extreme cases mentioned by theAuthor. Instances from the South and Centre of Ireland and fromthe Purbeck Limestone indicated some widespread cause, rather thanthe local one hinted at by the last speaker. He paralleled theaction with the dolomitization of limestones in Ireland, SouthWales, and the Isle of Man : cases in which dolomite-crystals ate Quart. Journ. Geol. Soc. Yol. LIV. PL XL ^ONSALL tvca^ta JtocJi Si QvLcvrt%cse Limestone. ^-iiiWii^^liliiilii^ d.
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Keywords: ., bookcentury1800, bookdecade1840, bookidquarte, booksubjectgeology
