LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 463 
The lines of division between no. 2, 3 and 4 are very indistinct 
and indeed their respective layers seem almost to pass into each 
other. No doubt the opening of the quarry was deeper when 
Vanuxem saw it for it has not been worked for many years and 
the floor is entirely hidden by soil. The rock is too compact for 
the exhibition of its fossils. If the quarry is again opened, as it 
no doubt will be during the improvements in progress on the Erie 
canal, the collection of fossils will be less difficult. 
. The farthest west of any exposure of Trenton noticed on the 
south side of the Mohawk was in the small creek which empties 
into the canal about a mile east of Port Jackson at an altitude of 
40 feet above the canal. This exposure consists of one thick layer 
of crystalline, fossiliferous Trenton limestone. 
In the valley of the South Chuctanunda creek are numerous ex- 
posures of the Utica shale. It outcrops in a fine cliff about 60 
feet above the canal. In the slope of the hill southwest of Mina- 
ville, at a point about 1.4 miles south by southwest of the center 
of the village, the Utica shale is exposed in several small glens. 
A section was measured here beginning at the level of the Chuc- 
tanunda and extending to the top of the hill. 
45K Minaville section 
K* Mostly covered. Thin sandstones and are- 
naceous shales with a massive 2 foot layer at 
the base in the head of a deep glen 120’==540" 
K? Black shales becoming olive to blackish at 
the top. These shales show a transition from the 
black arenaceous shales of the Utica to the are- 
naceous, thin, crumbling shales of the Hudson 
river stage. 165/420" 
K? Top consisting of slaty layers containing 
graptolites in abundance. Black, even shale. Gef—2 557 
K! Mostly covered, but showing brown-weather- 
ing, slabby shale in the west bank of Chuctanunda 
creek, just above Minaville. 165’—165/ 
The above section is the only one seen in this region that 
shows the passage from the Utica to the Hudson river stage, and 
is of special interest on this account. Within the limits of a con- 
tinuous exposure of 255 feet of shales there is exhibited a complete 
