Field Notebook: Massachusetts, New Hampshire, Vermont 1921
Page 28
Image from the Biodiversity Heritage Library. Contributed by Yale Peabody Museum of Natural History. | www.biodiversitylibrary.org
Transcription
Put up at 'The Maples' at Castleton, at $3.00 per day. As there are no granitic injections near the Ruskland area, about 30 miles (see p. distance) the intense metamorphism is due to regional deformation. If Doleritt's estimates of the thickness of the Cambrian is correct the load of the Paleogries may have been 3 miles thick, but finally much less. Leith thinks that the evidence points to deformation during the Appalachian orogeny, and that the mass a mile or more thick was shoved over the Ruskland area helping to cause further meta- morphism. Since then the core has been worn away revealing the intense metamorphism. Then too it is clear that the attraction increases from east to west. In the Bird Lines at Taconics the Lower Cambrian quartzites are thicker, 600 feet a mile, they thin out and in Conn. are only a few feet thick. Their greater mass as erosion intrudes