Iron ores, salt and sandstones . A few plagioclase feldspars remain practically unalteredand show characteristic twinning. The greater portion ofthe feldspar is either much altered or completely brokendown into aggregates of secondary minerals, muscovite,chlorite, calcite. and quartz, which completely fill the inter-stices between the grains. In some cases instead of a mosaicof these minerals, there is a considerable development ofsericite or chlorite, as if from a source other than feldspar,probably some original ferro-magnesian constituent. Thesesecondary minerals together with the silica co
Iron ores, salt and sandstones . A few plagioclase feldspars remain practically unalteredand show characteristic twinning. The greater portion ofthe feldspar is either much altered or completely brokendown into aggregates of secondary minerals, muscovite,chlorite, calcite. and quartz, which completely fill the inter-stices between the grains. In some cases instead of a mosaicof these minerals, there is a considerable development ofsericite or chlorite, as if from a source other than feldspar,probably some original ferro-magnesian constituent. Thesesecondary minerals together with the silica constitute thecement which forms a very resistant bonding material. Thecolor of the rock is due to the large development of secondaryminerals, chlorite, especially which gives the greenish tingeto the rock. The basal member of the Carboniferous Group of rocksis the Pocono sandstone which is not a quarry rock at anyplace in the state. Its economic value is in its gas and oilaccumulation in the so-called Keener and Big Injun WEST VIRGINIA GEOLOGICAL SURVEY. 527 DEVONIAN SANDSTONES. The Catskill sandstone is not quarried in this state. Avery durable brown sandstone outcrops high on the hills op-posite Rowlesburg in Preston county, and apparently corre-sponds in position to the Catskill. It has been opened as aquarry prospect by Mr. John F. Stoer. and shows a goodledge of rather fine grained brown sandstone which woulddoubtless prove to be a very popular trimming stone. ROWLESBURG Blue Stone Company Quarry at Rowlesburg. Rowlesburg in jPreston County is 26 miles east of Graf-ton on the main line of the Baltimore and Ohio railroad. Itis also reached by the Morgantown and Kingwood this place on the east bank of Cheat river and near theB. & O. railroad bridge, Mr. H. W. Rightmire operates asandstone quarry under the name of the Preston Blue StoneCompany. The floor of the quarry is below the level of the railroadabout 15 feet above Cheat river. The h
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishermo, booksubjectsalt
