180 GEEEN MOUNTAINS IN MASSACHUSETTS. 



through Berkshire up into Vermont. It has been shown to be of Cambro- 

 Silurian age. 



The Berkshire schist. — An overlying mass of schist forms the lower, 

 steeper slopes of the mountains on all sides. This is a part of the magne- 

 sian or talcose slate of Emmons, Dana's hydro-mica schist, and has come 

 to be regarded as of Lower Silurian age. 



The Bellowspipe limestone. — A series of limestone strata and calcareous 

 (sometimes noncalcareous) schists constitutes the higher benches, the Notch, 

 and the Farnham's Quarry area. In places the rock is quartzite. This 

 horizon seems to have been overlooked by previous geologists on Greylock. 

 In 1888 Mount Everett, near Sheffield, in southern Berkshire county ; Mount 

 Anthony, near Bennington, Vermont; Mount Equinox, near Manchester, 

 Vermont, and Mount Dorset (Eolus), near Dorset, Vermont, were visited by 

 the writer in the hope of finding again on some of these higher summits of 

 the Taconic range the upper limestone and calcareous schist of Greylock, 

 but a careful exploration of them all failed to yield any trace of this horizon, 

 excepting on Mount Anthony. A bench of calcareous schist occurs there 

 in the mass of schist above the limestone, but the relations are not suf- 

 ficiently clear to enable one to determine whether these calcareous layers 

 form part of the Berkshire schist or Bellowspipe limestone formations. Dur- 

 ing the year 1889, however, quartzites were found on Monument mountain, 

 in southern Berkshire, which appear to overlie the Berkshire schist, and 

 thus seem to belong to the Bellowspipe limestone formation. 1 



The Greylock schist. — A second series of schists similar to the lower 

 ones constitutes all the higher summits of the central ridge and the 

 top of Ragged mountain. This forms part of Emmons's magnesian or 

 Talcose slate and, together with the Berkshire schist, has been regarded by 

 Hall and Walcotl as of Hudson River age, and by Dana as representing 

 some member of the Lower Silurian. 



All these groups of strata succeed each other conformably. 



1 Tin- 1 1 1 ■ ■ < . i \ advanced by Mr. W. II. Hobbs daring the printing of this monograph (see Journal 

 ol i teology, vol 1. No. 7. Chicago, < >ctober-November, 1893, p. T2:>), that the limestone along the east- 

 ern foot of Mntiut Everetl corresponds to the Bellowspipe limestone and the schists which overlie it 

 to the Greylock schist requires verification to accord with results farther north. 



