468 C. H\ HITCHCOCK-^AMMONOOSUd DISTRICT, ttEW HAMPSHIRE 



famous Mount Willard locality by Doctor Hawes was not undertaken 

 till after the close of the survey. He had described a curious rock quite 

 near the fossils on Fitch hill under the name of novaculite, which re- 

 sembles the hornstone of the White Mountain notch. It is a light gray, 

 massive, homogeneous material resembling felsite, and, like that, fusible 

 before the blowpipe. As studied microscopically, it is found to be an 

 excessively fine grained mixture of much quartz, little orthoclase, minute 

 mica films, and grains of calcite. This compact rock, which originally 

 was slate, is so limited in amount on Fitch hill that no one can doubt 

 its origin from contact with diorite ; but there are many square miles of 

 similar rocks in the district which would be referred to a similar origin 

 were it possible to believe the thermal influences could have been so 

 widely extended. In my report I gave a local name to this material — 

 Lyman schist — and several ranges of it can be described. Doctor Hawes 

 speaks of it as identical with the novaculite, using the general name of 

 argillitic mica schist. It is composed of fine quartz, feldspar, mica, 

 chlorite, and various accessories. With much chlorite the color is green, 

 and a preponderance of the micaceous ingredient gives it a soapy feel. 

 The phyllites and mica slates belong to the same group. A careful 

 analysis by Hawes indicated that the sample tested had the composition 

 of an ordinary clay minus the larger part of the water, but he regarded 

 the mass as made up of recrystallized minerals, not fragmental. Still it 

 is a connecting link between argillite and mica schist. This does not 

 necessarily mean that the schist was not of fragmental origin — only the 

 primitive character has been obliterated. 



I have found many cases where the original fragments are still recog- 

 nizable. One is in certain parts of the distribution of the " auriferous 

 conglomerate." The pebbles show unmistakably on the smoothed sur- 

 faces of the ledge, but when cleaved the interior has the perfectly foliated 

 structure of argillitic material. Even the silica has become a silicate. 

 Some of these rocks weather so as to show pebbles several inches long, 

 but every pebble is of the same hornfels as the entire mass when the 

 structure has been obliterated. All these homogeneous rocks weather 

 extensively, so that they can be recognized at once by their light color. 

 We called them the " white schist " when in the field. 



In Littleton there is a band of these white schists adjoining on the 

 west side the chloritic granites and slates. In Lyman it seems to merge 

 into a very coarse conglomerate, entering the town on the east side of 

 Partridge lake, and it is also a prominent rock on Mormon hill. The 

 high land east of Parker hill (Lyman P. O.) shows the same rock, and 

 it continues, partly covered by argillite, to the extreme southern end of 

 the district at Woodsville. There is a repetition of these argillitic schists, 



