

walcott.1 GRANULAR QUARTZ. 95 



the Geology of Massachusetts, 1 in which the quartzite is described with 

 many details. In the table on page 303, the " Granular Quartz " is 

 placed at the base of the Paleozoic, or Sedimentary series, that is, at 

 the base of the stratified rocks. 



Dr. W. W. Mather, 2 in his survey of this region, concluded with Prof. 

 Kogers that the u Granular Quartz" and other rocks referred to the 

 Taconic by Emmons were the same as those of the Cham plain division 

 of the New York section, modified by metamorphic agency and the in- 

 trusion of Plutonic rocks. This correlates the " Granular Quartz" with 

 the Potsdam sandstone. The " Granular Quartz " and the Potsdam 

 sandstone were referred to the Primal series by Prof. H. D. Kogers 3 

 along with all the quartzites that were found at the supposed base ot 

 the Paleozoic series in the Appalachian region and north through New 

 York and Vermont into Canada, aud westward into the Mississippi 

 Valley. This reference to the Primal series is more fully described in 

 the final report of the Geological Survey of Pennsylvania. 4 



Prof. Ebenezer Emmons described the " Granular Quartz" with con- 

 siderable detail as the basal member of his Taconic system. 5 In the re- 

 ports of 1844 and 1847 its occurrence in western Massachusetts and west- 

 ern Vermont is noticed, and it is stated that in all probability it occurs 

 as far north as the Canadian border. Its extension into Vermont had 

 been previously noted by Messrs. Eaton and Dewey, and we find in the 

 first annual report of the Vermont survey the statement by Prof. C. B. 

 Adams 6 that a quartz rock constitutes the western base of the Green 

 Mountains from the north part of Addison County to Massachusetts; 

 aud it is further said 7 that the quartz rock accompanies the Stockbridge 

 limestone, disappearing with it in the north part of Addison County, 

 and that near Lake Dunmore a bowlder was found in the vicinity of the 

 quartzite beds containing two remarkable species of Polyparia(f). Two 

 years later, in speaking of an excursion into Bennington County Prof. 

 Adams says that the Quartz rock may equal the Potsdam saudstone, 

 but there has evidently been too great a disturbance in this region to 

 admit of certain conclusions. 8 



A full description of this formation's presented under the heading of 



1 Final report on the geology of Massachusets, vol. 2, 1841, pp. 560-593. 



2 Mather, William. Natural History of New York. Pt. 1, Geology of New York; geology of the 

 first (southeastern) district. Albany, 1843, p. 438. 



3 On American Geology and present condition of geological research in the United States. Am. 

 Jour. Sci., vol. 47, 1844, pp 151-154. 



4 The geology of Pennsylvania. Philadelphia, 1858, vol. 2, p. 751. 



6 Geology or New York, pt. 2, comprising the survey of the second geological (northern) district. 

 1842, pp. 135-164. The Taconic System ; based on observations in New York, Massachusetts, Vermont, 

 and Rhode Island, pp. i-vii, 67, 6 plates, Albany, 1844. Agriculture of New York, vol. 1. pp. 45-112, 

 plates 21, map. Alhany (1846), 1847. American Geology, containing a full statement of the principles 

 of the science, with full illustrations of the characteristic American fossils. 8vo. Albany, 1856, vol. 

 1, pt. 2, pp. 122. 



6 First Annual Report on the Geology of Vermont. Burlington, 1845, p. 57. 



7 0p.cit.,p. 61. 



8 Third Annual Report on the Geology of the State of Vermont. Burlington, 1847, p 13. 



