Reviews. 



Report of the Vermont State Geologist, 1 901-1902. 190 pages; 62 

 plates ; 2 maps. 



This volume seems to mark, in a way, a fresh start in geological 

 work in Vermont, made possible by more adequate provision for the 

 work of the state geologist. The first thirty pages are devoted to a 

 resume of past geological work in the state, including (i) a sketch of 

 the life of Zadock Thomson, state geologist 1853-56, together with a 

 list of his publications ; (2) a list of reports on the geology of Vermont, 

 1 845-1 900, with a summary of the scope of each report; (3) a list of 

 other publications bearing on Vermont geology; and (4) a biography 

 of Mr. Augustus Wing (1808-76), an independent investigator who 

 made important contributions to the knowledge of Vermont geology. 



Then follows a summary of the metallic products, useful minerals, 

 and building-stones of the state. Mr. George I. Finlay contributes 

 the results of a study of the Barre Granite area, one of the most impor- 

 tant granite areas in the country, the workshops at the Barre quarries 

 being the largest of the kind in the world. A detailed petrographical 

 description is given of the granites and their associated rocks. 



"The Terranes of Orange County" are discussed by Dr. C. H. Rich- 

 ardson. The slates of Montpelier and Northfield, and those extending 

 north and south from Bradford, which have been regarded as Cambrian, 

 are placed by him in the same horizon with the " Calciferous Mica 

 Schist" of Hitchcock, on stratigraphic grounds.. The latter is sepa- 

 rated by Richardson into a calcareous member, the Washington limestone, 

 and a non-calcareous member, the Bradford schist. These have been 

 regarded by most geologists as Silurian (Upper Silurian), but are placed 

 by the author, together with the slates, in the Lower Trenton, on the 

 ground of the lithological similarity of the slates with the graptolitic 

 slates of Trenton age at Willard's Mill and Castle Brook, Quebec. The 

 slates are shown to rest unconformably on the Huronian, and so the 

 Cambrian, according to this classification, is absent. A more detailed 

 statement and discussion of the evidence for this important change of 

 correlation would be of interest. It may be noted that in accounting 

 for the break in the outcrop of the slates near Bradford by erosion 



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