J. D. Dana—Note on the Pernardston Helderberg Formation. 881 
“ ie the quartzyte is Helderberg as much as the lime- 
sto 
9, “Phat the garnetiferous mica slate is equally Helderberg. 
3. That the limestone is a lo Ser pod pete between the other 
Sean of the Helderberg format 
4. That hornblende rocks, sinuroiti tae mica schist and 
gneiss of the adjoining region on the and northeast are of 
e and the same geological ‘ornate 
. The Quartzyte as of the Helderberg formation. The overly- 
aa quartz te (No. 4) besides occurring in large outcrops over 
the hill-side, constitutes the upper two to four feet of the vertical 
section exposed in a portion of the limestone quarry. is 
alone proves its conformable position and close relation to the 
limestone. But further, while this overlying quartzyte is in 
part very compact and solid, some portions are very cellular from 
the removal of calcareous matter nd pyrite, and also from the 
removal of fossils. The first of the fossils was found by Pro- 
fessor Emerson, while we were together, an 
h 
. pseudo-galeatus, a Low Rpt cstes Se species. Besides these 
brachiopods, there were in the same layers of the reader dem 
humerous fragments of erinoidal pare mostly of small species. 
Some of the lamine of this quartzyte ‘have be tween them mica 
in seales, so as to look in a surface view like mica schist 
The fact that there is conformability between the limestone 
and quartzyte is hence beyond question. And it is equally cer- 
tain that, overturned or not, the quartzyte belongs to the same 
extremity of the State near the Massachusetts boundary, Mr. C. H. Hitch- 
Sock describes the hornblende rocks of Vernon and Bernardston as associated 
m 
also “invariabl renting upon the quartz rock” and hence ‘‘ newer” than it; 
as, th pa F rivegrans Bec! the Sacer r Helderberg age, like the Hebron lime- 
stone (H (Hall’s first d pel eat which rests on the same quartz rock; thus mak- 
ing the ‘whole series Upper Helderberg. The unconformability e the quartz 
tock series on the clay slate is also recognized. 
re still his vee except ng the change of Upper Helderberg to 
Lower Helderberg, ie should be in close agreement. In my arguments above, I 
fact sustaining Mr. C. H. Hitchcock of 1861, against Professor C. H. Hitch- 
ba pe wen conclusions have been influenced by his faith in the 
aE 
g 
bd oo by C. H. Hitchcock,” and the poem 0 fos pad that oe pies on 
i were prepared by any other person. 
