550 STRATIGRAPHICAL GEOLOGY. 



the lines as well as possible, and beg the indulgence of future observers 

 should any of the boundaries prove to have been incorrectly delineated. 



Subject to these modifications, therefore, I shall include the Allenstown 

 quartz with the Lake gneiss, and draw the northern boundary of the forma- 

 tion a little beyond what the mineral character of the rock would seem 

 to warrant, including quite a large portion of Allenstown. This will bring 

 the well-known Hooksett granite into the Lake series, as well as that of 

 Manchester. Either one of these deposits might be said to be a Mont- 

 alban synclinal outlier, resting upon the Lake gneiss, should the imme- 

 diately associated layers make such reference desirable. I have not 

 separated the granites of the Lake series from the gneisses on the map, 

 as is the case with the Montalban. Near the east corner of Hooksett, 

 upon Gate's hill, is a hard, jointed, granitic gneiss, just beyond the quartz. 

 Two lines of travel cross the country farther west in Hooksett, between 

 the two quartz beds, nearly at right angles, and may be taken on either 

 side of the Merrimack river. Starting with Campbell's hill, we find the 

 quartz dipping north-west, and then the rocks are concealed by allu- 

 vium for more than a mile. Next follow nearly two miles' width of the 

 granite that is so extensively quarried on the hills east of the railroad. 

 The sheets of granite on the hill dip from forty to fifty degrees north-west. 

 The strata are more nearly vertical half a mile north, with large veins of 

 very coarse granite. On both sides of the Pinnacle quartz range are hard 

 granite layers. In the river below the railroad bridge the rock is dis- 

 tinctly gneiss. The dips are north-westerly. On the west side of the 

 river, in Hooksett, all the strata .dip in the same general direction. A 

 coarsely crystallized rock crops out by W. Taggart's. The road nearest the 

 west part of Manchester and Goffstown runs over granite similar to that 

 quarried, save a patch of mica schist, at the south corner and on the very 

 west, line dipping io° N. W. Adjacent to Bow line the soil is entirely 

 ferruginous, and the rocks very much so. The granite is quarried some- 

 what in the bend of the Merrimack river in the south part of Hooksett. 



New Boston is mostly underlaid by the Lake gneiss. The most 

 characteristic lines of outcrop have been discribed in Figs. 88 and 89. 

 Gneiss is the prevailing rock on the high land parallel with the Piscata- 

 quog river on the north side. It occurs near the village, two or three 

 miles south, by B. Hopkins's and a saw-mill. The layers resemble 



