44 The American Geologist. January, looi. 
Dr. Henry S. Washington read a paper on "The Rocks of Lake 
Winnepesaukee, N. H.," as a preliminary report on work done by 
Prof. Pirsson and himself on mount Belknap and Red hill, near 
lake Winnepesaukee, N. H. The rocks of mount Belknap are shown 
to be prominently a quite uniform alkali syenyte, which is cut by 
many dikes of camptonyte and allied rocks, and of bostonytes, aplytes, 
and syenyte porphyries. These dikes also cut the surrounding por- 
phyritic gneiss. At one place, near the border, is a mass of basic 
hornblende-gabbro, with large poikilitic phenocrysts of brown horn- 
blende. A syenyte breccia also occurs. At Red hill similar syenyte, 
formerly described by W. S. Bayley, occurs on the summit, while to- 
ward the periphery, nepheline appears as a constituent, and a true 
foyayte is developed. The massif is also cut by dikes, both camp- 
tonitic and syenitic. The region is to form the subject of a petro- 
graphic study by the two geologists in the near future. 
Professor Daniel S. Martin described a visit which he paid to 
the noted mineral locality at Haddam, Maine, during the summer. 
He described the manner in which the choicest specimens occur 
there, in veins of albitic pegmatyte, with tourmaline, muscovite and 
quartz along the contact with the wall of gneiss. The mica plates 
along the contact are often two feet in diameter. 
Dr. a. a. Julien in his paper "The Geology of Central Cape Cod," 
reviewed the opinions of Mitchell, Davis, Shaler and others on the 
geology of cape Ann, with especial reference to the district from Chat- 
ham to Yarmouth. In the stratified deposits of sands and gravels 
which underlie the plains south of the morainal "back-bone" of the 
cape, the more frequent intercalation of clays was pointed out, and 
their occasional disturbance and flexure. Striated pebbles, although 
much water-worn, are quite largely interspersed. The discovery of 
true glacial silt at some depth, in one locality, indicates that the ice- 
sheet there rested, instead of floating. The kettle-shaped hollows and 
pond-basins were shown by the speaker to be largely connected with 
the damming of surface streams, and some observations on the pre- 
glacial drainage valleys and topography were discussed. The identi- 
fication of certain transported fragments of quartz-porphyry with 
outcrops of the same near Marblehead indicates a pre-glacial movement 
from N. W. to S. S. E. To the fifteen changes of level which have 
been recorded, a final small elevation probably should be added, judg- 
ing from the low terrace along this part of the coast. Examples of 
the facetted pebbles were exhibited and provoked considerable dis- 
cussion among those present, as to the origin of these pebbles. 
Prof. Richard E. Dodge recounted his pleasure in visiting the 
region of the Colorado canyon, during the past summer, in company 
with a party, and finding the physiography so graphically illustrated 
in the drawings in Powell's reports, to be a most faithful and non- 
diagrammatic portrayal of the features themselves. He then de- 
scribed the striking examples of gigantic geo-physical results seen 
in the Great Kaibab anticline, the Grand Canyon itself and the Kaibab 
