106 J. D. Dana—Origin of the Rocks.of the Cortlandt Series. 
more distinctly before the reader, and especially the relations 
of Stony Point to Montrose Point and other places on the eas 
side of the Hudson. 
The eastern outline of the Archean makes a large angle at 
the crossing of the Hudson (the course on the west being north- 
east, and that on the east, east-northeast), so that the form was, 
thus far at least, favorable for the existence there of a broac 
bay in the Lower Silurian sea. The river-channel through the 
Map of parts of New York and New Jer- . i =| 
sey: ST, Stony Poi 
the Hudson; v, Verplanck Point, on the 
east side; cR, limestone about Cruger’s 
Station. Scale, 10 miles to 1 inch. 
B UIA 
Il 
ARCH AAN LIMESTONE 
NE 
. “ey 
acti Tas ce ps 
ee ee 
Pu. WESEPOLN Te 
vee * Ve FE 
, 
2 
cd 
Lat 
” 
FRANKLIN ed ee 
Highlands had not yet been made, as is indicated by the con- 
tinuity of the Lower Silurian beds on the north of the High- 
and area across from Fishkill, and that of the same on the 
south across from Peekskill. 1e Lower Silurian ocean ex- 
tended over the Cortlandt area, and here were spread out the 
sand-beds and muds that now constitute the quartzyte and 
slates of the Potsdam or Primordial (Cambrian) period and the 
material of the limestone formation. North of the Archxat, 
in the Fishkill, Newburgh and Poughkeepsie regions, fossils 
found in the limestones and hydromica schist have demonstrated 
~™ 
that the beds there are beyond question Lower Silurian ; and 
