146 
The American Geologist. 
March, 19(X» 
Clinton 
Medina 
Oswego 
sandstone 
63 Grayish ss. or arenaceous 
and argillaceous shale; 
slight effervescence in 
HCl on heating. Clinton 
100 Ditto, but mainly gray 
shale with some reddish 
grains of iron and iron 
pyrites. The grains seem 
to be oolitic and are 
hematite. 
115 Mainly clear light gray to 
white quartz sand. Some 
chips of dark gray shale, 
probably from above. 
135 Clear bluish-gray argillace- 
ous shale. 
150 Light gray slightly green- 
ish ss. composed largely 
of moderate sized quartz 
grains with some iron 
pyrites. A few chips of 
greenish argillaceous Oswego 
shale. sandstone 
286 Mainly chips of light and 
dark gray very silicious 
ss., with some dark gray 
to bluish argillaceous 
shale. The ss. is com- 
posed mainly of fairly Oswego 
small quartz grains. sandstone 
31G Mainly light gray quartz 
grains with a slightly 
pinkish tint. Some chips Oswego 
of dark gray shale. sandstone 
335 Greenish-gray, fine grained 
quartz ss. and greenish Oswego 
argillaceous shale. sandstone 
380 Ditto with blue arenaceous Oswego 
and argillaceous shale. sandstone 
420 Ditto, but chips are coars- 
er. Grains of iron py- Oswego 
rites are quite common. sandstone 
469 Ditto. Oswego 
sandstone 
