Mar., 1910.] 
Pennsylvanian Limestones. 
IOI 
appear to be closer than they really are. Ordinarily it is not 
possible in a limited outcrop to determine whether undulation 
exists or not. Therefore in sections where limestones are shown 
to be unusually close together or unusually far apart it is only 
fair to suppose that undulation is probably the cause provided 
the difference be not over 15 to 17 feet as no undulation observed 
exceeds that measurement. 
In the above quarry the rise and fall was not observed to 
exceed 6 or 7 feet and no definite order was discovered as the 
rising and falling occurs, no matter in what direction the obser- 
vation be made. The limestone merely conforms to the topog- 
raphy of the sea bottom on which it was laid as a mud without 
becoming thicker in the depressions and thinner on the elevations 
of that bottom. Had the mud or ooze been considerably greater 
in specific gravity than the water in which it was laid it would 
doubtless have glided slowly into the depressions where the 
greater slopes occur and thus cause the upper and lower surfaces 
to be less parallel than we find them. 
As nearly as could be determined from a topographic map the 
top of the Vanport lies at 1 ISO above sea as seen in the hill-top 
directly north of the quarry and the Putnam Hill lies 37 feet be- 
low, or 1143 above sea as measured in the northeast corner of the 
quarry. 
The following section measured near the center of the quarry 
represents the character of this limestone fairly accurately. 
Feet Inches 
Brown arenaceous shale 1G 6 
8. Limestone layer 1 7 
7. Parting, calcareous shale 0 2 
6. Limestone layer 1 4 
5. Limestone layer 0 7 
4. Limestone layer 1 11 
3. Limestone layer 1 8 
2. Parting, thin shale 0 0 
1 . Limestone layer 0 11 
Coal 0 11 
No. 8, or the top layer of limestone, is perhaps the most dis- 
tinct layer in the quarry and is readily recognized in any part of 
the quarry where it has not been cut away by the ice. The 
shale parting beneath gives it the well marked separation from 
the next layer. On weathering it tends to split up into numer- 
ous thin layers and does not appear to be as pure a lime as the 
lower layers. 
No. 7 is a conspicuous parting of bluish calcareous shale of 2 
inches thickness. It is the most sharply defined and constant 
plane of separation in the quarry. 
