ALGONKIAN ROCKS IN VERMONT. 403 



1 86 1, by the statement of the elder Hitchcock that such is 

 the structure. Numerous sections across the range are given 

 in which its anticlinal nature is brought out. Much evi- 

 dence is adduced in the text pointing to the same conclu- 

 sion based mainly on the occurence of a quartzite and con- 

 glomerate on both sides of the range associated with limestones. 

 Edward Hitchcock, in 1847, had published sections which 

 represented the range as an anticline slightly inverted by 

 overturning towards the west. Adams, in 1845, had somewhat 

 disconnectedly stated that the "granular quartz-rock" of the 

 Taconic had an inverted dip,' but did not include in the Taconic 

 rocks east of the quartz rock. 



In all, the geology of Vermont (1861), contains twelve 

 sections east and west across the State. Of these, eleven 

 traverse the Green Mountain gneiss ; the four southern ones 

 show several synclines and anticlines in the gneiss ; section 

 V, one broad anticline; sections VI, VII, and VIII represent 

 the anticline overturned to the west ; and in sections IX, X, 

 X^, and XI the gneiss is given a simple anticlinal struc- 

 ture. On the west side of the range, in all sections except 

 the fifth, the quartz rock is given an easterly dip of varying 

 angle due to inversion. With one exception, at North Ben- 

 nington, where the quartzite dips easterly at an angle of 

 5° to 20°, nearly in the position it was laid down, the writer 

 has not seen an easterly dip in the rock along this belt as far 

 north as Pittsford. The rock is usually quite massive and flinty, 

 and bedding is not discernible. An easterly-dipping jointing is 

 easily mistaken for stratification. Rocks immediately below 

 have a lamination that dips easterly at a high angle, and the 

 inversion argued is based largely upon observation on this struc- 

 ture ; the coincidence of lamination and bedding along the western 

 border has already been spoken of as the probable reason of the 

 elder Hitchcock's accurate decipherment, in 1847, of ^he real 

 altitude of the main axis of the mountains in Massachusetts. 

 In 1868 the younger Hitchcock reiterated the interpretation 



' First Annual Report on the Geology of Vermont, 1845, p. 61. 



