DESCRIPTION OF THE GENERAL SECTIONS. 649 



grained variety and the Moose Mountain Coos development. The west- 

 ern part of it is coarsely porphyritic. 



In Hanover we find on Moose mountain a conspicuous and persistent 

 range of quartzite, standing nearly vertical, and not exhibiting, so far as 

 understood, any folding. It is overlaid by staurolite mica schists, dipping 

 westerly, and, it is supposed, beneath clay slates of the later part of the 

 Coos age. These last are disposed in the double basin attitude, supposing 

 that the western part, consisting of purely vertical strata, is a fold closely 

 crowded. They bear some resemblance, however, to the Cambrian slates 

 of the Connecticut valley (p. 394). The segment of micaceous schist fol- 

 lowing belongs to the upper part of the Bethlehem group; and I have 

 sometimes represented it as separated by a fault from the slates on the 

 east, and the typical Bethlehem area on the west. They have an east- 

 erly dip throughout. West of Mill village follows next the Hanover area 

 of Bethlehem gneiss of the typical variety, a coarse protogene gneiss. 

 The structure of this has been studied more than that of some regions, 

 because of its situation near the head-quarters of the survey; and we 

 are well satisfied it is an inverted anticlinal dipping westerly. A band 

 of white quartz traverses it like those so often referred to in other for- 

 mations. On the west side of it is a repetition of the Moose Mountain 

 quartzite and mica schist, less in their thickness but identical in composi- 

 tion and age. Their dip is westerly, the same as that of their analogues. 

 On the college grounds the hornblende schist, inverted over the Coos 

 slates, makes its appearance, dipping to the west. It is about a mile wide, 

 and may be seen in close contact with the Lisbon group of the Huronian 

 in Norwich. A careful analysis of this formation in Norwich (p. 363) 

 shows the probable existence in it of five flexures. I doubt not similar 

 reduplications can be found in every town of the state, if explored as 

 thoroughly as these conveniently-situated ledges near our head-quarters 

 have been. Next occur the Cambrian clay slates, monoclinal, and in their 

 natural place between the Huronian and Calciferous groups. The latter 

 exhibits through Hartford a synclinal structure, and on the west side 

 succeed micaceous quartzites dipping easterly beneath them. The latter 

 I have referred to the Coos group, believing the calcareous strata usually 

 overlie them. The area occupied by similar non-calcareous schists is 

 quite large in Vermont, and I have not yet been able to satisfy myself 

 VOL. II. 82 



