400 THE JOURNAL OF GEOLOGY. 



the localities examined by him ; in a general way the structure is 

 that of an overturned series of folds, of an extremely compli- 

 cated nature. These sections were made particularly to illustrate 

 the structure of Hoosac Mountain, and the structure suggested 

 in 1847 finds its verification in 1889^ in Massachusetts, as far as 

 the overturning of the anticline to the west is concerned. At 

 that time little reference was made to the age of the rocks 

 exposed along the axis, but they were mentioned as probably 

 older than the Lower Silurian, while their relation to the younger 

 rocks was not considered. 



Zodack Thompson, in 1856, in considering the "Taconic 

 System," makes reference to the structure of the rocks along the 

 Green Mountain range ^. 



He remarks that "one of the most marked peculiarities in 

 the geology of Vermont is found in the general dip of the strati- 

 fied rocks, which is, with a few trifling exceptions, toward a 

 synclinal axis extending north and south near the center of the 

 Green Mountain range." He notes a general westerly dip on the 

 east side of the range, and an easterly dip on the west side. 

 However, the question as to whether the Green Mountain rocks 

 are really primary or post-Taconic was with him still in doubt, 

 but he states that the weight of the evidence points towards the 

 latter view, or more recent age. 



In 1868, T. Sterry Hunt, after a study of the literature, while 

 discussing Vermont geology, comes to much the same conclusion 

 as Thompson. 3 To use his own words : " All the evidence, 

 palaeontological and stratigraphical, as yet brought forward, 

 affords no proof of the existence in Vermont of any strata (a 

 small spur of the Laurentian excepted) lower than the Potsdam 



'See part 3, "Geology of the Green Mountains in Massachusetts," by R. 

 Pumpelly, J. E. Wolff, T. Nelson Dale, and Bayard T. Putnam. Monograph U. S. 

 Geol. Survey. Submitted in 1889. Not yet issued. 



^Preliminary Report on the Natural History of the State of Vermont. Augustus 

 Young. 1856. Extract from Zodack Thompson's address on the Natural History 

 of Vermont. App. 6, p. 67. 



3 On some points in the geology of Vermont, T. Sterry Hunt, Am. Jour. Sci., 

 2d series, Vol. XLVI., 1868, p. 229. 



