PHILOSOPHICAL SOCIETY, UNIVERSITY OF VIllGINIA 





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Fig. 1. JNIiCROPHOTOGRAPH OF A Thin Section of Zirconiferous Sandstone 

 Obtained Three Miles West of Ashland, Virginia. 



The grains of high relief showing rounding from wear are zircon; the smaller, angu- 

 lar, white grains are quartz ; and the black groundmass is mostly ilmenite; the whole is 

 cemented with limonite. Magnified 97 diameters. 



Fig. 2. Microphotograph of a Thin Section of Zircon-Bearing Sandstone 

 Obtained Three Miles West of Ashland, Virginia. 



The white, angular grains are mostly quartz with a few of feldspar; the scattered 

 roundish grains of high relief are zircon, and the black groundmass is mostly limonite, 

 which forms the cement, with some grains of ilmenite. Magnified 97 diameters. 



