LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 451 
hundred feet up the steep hillside. The lowest exposure is just 
beneath the arch of the West Shore railroad bridge where crumbling 
shale is exposed in the creek bed. Beginning at this point a sec- 
tion was measured by means of tape and Locke level. 
2I Rotterdam section 
I? Near the railroad arch in the bottom of the 
creek 8 feet of very thin, fragile, dark grayish to 
bluish black, argillaceous shales with occasional 
very thin sandy layers, one near the middle of the 
stratum being about I inch thick. Sie 
I? Heavy, compact sandstone of grayish to 
greenish blue color, weathering gray to brown. 10 Per 
I? Mainly grayish, friable shales with thin layers 
of sandstone. - 121130" 
I* Heavy sandstone with intercalated shale. 6/2): 26! 
I® Dark crumbling shale. Si ay 
I6 Shale with mainly thin, but some heavy layers 
of sandstone. 27 eke 
I’ Heavy stratum of sandstone. Mem Paar ls 
I$ Shales with some thin layers of sandstone. EE) FOR 
I® Thick to thin and broken layers of sandstone. 10’ TI? 
1°. Fine shale. 5/== 335? 
It Thin broken sandstone with crumbling shale. 45/—= 160" 
PeShale: i, F057 
[8 Thin sandstone and shale. Base of high © 
waterfall. | age 
I+ Thin friable blackish shale by excavation of 
which from beneath the sandstone above, the fall 
has been formed. Pe toy 
I Two layers of massive sandstone over which | 
the water falls. S—— 1Oor 
[16 Thin sandstone layers. ep Tf 
Ee Clear darlc, shale.) +” 4’= 1907 
[18 Apparently heavy bedded sandstone weather- 
ing to thin often lenticular divisions. 20 -2arh 
I'® Shales and thin sandstones. 1o'=5 283" 
1° Medium thick layers of sandstone with mas- 
‘sive 2 foot layer at base and some thin beds of 
shale, and shaly partings. 30'== 270’ 
