992 — SJ. DA Dana—Taconic Rocks and Stratigraphy. 
limestone in Canaan. These quartzyte areas have a hard, gray, 
well banded gneiss in close proximity, the age of which,— 
whether of the Quartzyte formation, or of the Archean, I leave 
for later discussion. 
One well-displayed example of the overlying of limestone by 
quartzyte conformably occurs in New Marlboro, north of. 
Canaan Valley (at 14 on the map). Fig. 21 represents the sec- 
tion. But it is possible that the overlying is a consequence of 
21. 
& 
an overturn fold. The quartzyte is of the hard massive kind. 
It is on the east margin’of the area which has a bed of kaolin 
on its west margin. 
There is one feature of several of the quartzyte beds that ap- 
pear to be underlying, which, on further study, may become 
good lithological evidence of age. This is the occurrence! 
some of them of a large amount of the coarsely-feldspathic vane 
ty of quartzyte, and as a consequence of this, the existence ? 
or near them of large beds of kaolin. Such a conjunction 
occurs in the quartzytic region of northeastern Sharon and 1? 
others to the north in Berkshire. The case of New Marlboro 
is probably one of these, although the feldspathic variety of the 
quartzyte has not yet been found there in place. : 
I omit further remarks on this lower quartzyte and its 
tions to the associated schists, including the adjoining gue! 
until I have given the subject another season of fiel study. 
The lithological facts from the region considered illustrate 
an important principle in regional metamorphism; the results 
as to degree of change, and kinds of minerals produced, an 
geographically gradational, they varying regularly from north 
to south and from west to east. A review of the facts on ©” 
point will close this part of my paper. 
[To be continued.] 
rela- 
