GEOLOGY OF THE MERRIMACK DISTRICT. 485 



pyritiferous schists. At A. Whittemore's, in Marlow, west of Grassy brook, 

 we have a fine-grained gneiss. On this road, from the Hne of Marlow to the 

 village, the micaceous gneiss was not seen. As we go south from the 

 west part of Alstead into Surry, the rocks have a more definite character, 

 although the typical variety of the common gneiss has not been seen in 

 any extended outcrop. There is gneiss east and south-east of the village. 

 Even here the rocks are more allied to the protogene than the common 

 gneiss, and they are probably varieties of it. We find gneiss on the road 

 to Mine ledge, and on the road south it can be seen at E. Woodward's ; 

 from thence to Keene there are no ledges of any kind ; neither are there 

 any ledges on the direct road from Surry to Keene. As there is some 

 doubt whether there is any outcrop of the typical variety of the com- 

 mon gneiss in Keene, the rock is described under protogene gneiss, 

 which is the prevailing rock. In the central and south-east part of West- 

 moreland we have a gneiss that is, at least, closely allied to that in the 

 northern part of this district, and northward. Specimens of the reddish 

 variety of protogene gneiss from Surry and Keene can hardly be distin- 

 guished from some specimens of the gneiss obtained in Jefferson, near 

 the Mt. Adams house. 



The northern and western limit of the gneiss, including the protogene, 

 is as follows : A line drawn from a point just north of school-house No. 

 4, in Surry, to the tannery north-west of Westmoreland village, would 

 represent the boundary on the north-west. This, continued to the south- 

 west nearly to the molybdenite mine, then sweeping round into the edge 

 of Chesterfield, just north of L. Pierce's, would represent it on the west ; — 

 the line then extends to the north part of Spofford pond, crossing it, and 

 runs south of A. Chandler's ; then round to Factory village, crossing the 

 outlet of the lake, striking the stream again by the lower mill, crossing the 

 road near E. R. Wellington's, and turning southward to the forks of the 

 road east of school-house No. 14: this represents its south-western bound- 

 ary. South of the east part of this line, between the gneiss and the por- 

 phyritic gneiss, we have an oval area of mica schists, quartzites, and 

 conglomerates. The area in the east part of Westmoreland is noticed 

 under protogene gneiss. The gneiss outcrops at the harness shop 

 near D. Warren's, on the top and east side of the hill west of Mrs. Car- 

 lisle's, at J. L. Paine's, at O. Leonard's, and J. Briggs's, Jr. South of the 



