Page:The Journal of geology (IA journalofgeology11893univers).pdf/296
that a number of small limestone areas near Lakeville, in which the strata are but gently inclined, are capped by a schist. This schist he believed to be the same as the schist of the southern extremity of the mountain. He says, speaking of these areas (p. 272):
"Since the limestone is the underlying rock, they are all, if not monoclinal, as is hardly possible, small overturned anticlinals, which have had their tops worn off so as to show the limestone beneath."******
"The synclinal structure of the mountain is apparent also along portions of the southern edge of the schist. At Ore Hill, one and a half miles west of Lakeville, the schist overlies limestone."
On page 273 he says:
"The ore-pits that have been opened about the base of Mt. Washington, fourteen in number, are situated near the junction of the limestone and schist, and in view of the facts that have been mentioned, this means—near where the limestone emerges from beneath the schist."
Referring to the dying out of the synclinal to the south of the mountain, he says:
"Again the pitch of the beds in the last three miles is southward in some parts, instead of eastward or westward, showing a flattening out of portions of the synclinal and subordinate anticlinals."
"It thus appears that in the dying out of the synclinal, besides a flattening of portions of the general synclinal and the introduction of southward dips, there was also a multiplication of small subordinate flexures."
"Farther there is a multiplication of ridges of schist in the limestone area."
"Several such ridges, some quite small, are situated, as the map shows, southeastward of the mountain near the village of Salisbury; and others occur farther east. They consist of the same mica schist as the mountain,—they have generally an easterly dip, often a high dip; and the facts seem to show that most of them are synclinal flexures; that they occupy the troughs of local synclinals in the limestone;***. Most of them were, apparently, half-overturned troughs so pushed over westward that the dip of the schist is generally eastward."*******
The following is quoted from a paper[1] entitled "Berkshire Geology" (pp. 15-16):
"The Mt. Washington schists lie in a trough very much like that of Greylock, but one relatively shorter in its narrowed part and reversed in position. In the northern half the trough is a very broad shallow one, while to the south the east side is pushed up westward."
- ↑ Berkshire Geology, by Prof. James D. Dana.A paper read before the Berkshire Historical and Scientific Society of Pittsfield, Mass., February 5, 1885.Pittsfield, 1886.