



Fig. 7 Photomicrograph taken in ordinary light, magnification 65 diam- 

 eters. Specimen of Poughquag quartzite from a ledge resting unconformably 

 on the gneiss, about three-fourths of a mile west of Ladue's farm; the 

 rock is inferior to that shown in figures 5 and 6. Note the distribution 

 and quantity of minerals other than quartz. 



