BEENAEDSTON SEEIES OF UPPEE DEVONIAN. 



295 



Under the microscope gi-ains of cjuartz appear scattered in a very 

 fine-grained mass of plumose liornl)lende. Bands of calcite run throuo-h 

 this, made up of several layers, with much acicular lioniblende developed 

 in it. The calcite grains are ijolysynthetic. The hornblende is partly 

 decomposed into a bright-green, apolar serpentinous mineral. 



ROCKS AT THE MOUTH OF MIL,L,ERS RIVER. 



Southward from Northfield the Triassic sandstones border the river on 

 the west and older gneisses approach it on the east, and the first exposures 



co,v N ec r / c u T^ 



Fici. 211. Sketch map of rocks i 



nth of Millers River, Er 



which can be compared with the Bernardston series appear in the east 

 bank of the Connecticut 5 miles below Grass Hill and just above the 

 mouth of ^lillers River (figs. 20-22). Here, for nearly a mile, there is an 



MiJ/ers^ffiver — 



Fig. 21. Sketch of rocks at montli of Millers River, looking northeast from B on map, fig. 20. Scale, 1: 2000. H. S.= 

 hornblende-schists; Q. = qaartzite: GN. = giiei8S; GH. = granite; M. S.=mica-schi8ti B. G!J.=hiotitegiieiss; Older 

 GN.r^Monson Cambrian gneiss. 



unbroken exposure of rocks of great interest, which I have associated with 

 the Bernardston series, at times with much confidence and at times very 

 doubtfully. It becomes, in fact, a question how far the original sediments 

 may have been different from proximity to the gneiss instead of the argil- 

 lite, and how far, also, the immediate presence of the gneiss during the 

 thorough metamorphism of the sediments in question may have conduced 



