Geology of southwestern New York. — Harris. 165 
gas — the objects sought — were met with in paying quantities. 
To the geologist, however, the extensive suit of drillings, carefully 
preserved and labelled, are of uncommon interest owing to the 
depth and peculiar location of the well ; it furnishes him data for 
determining the lithological characters, thickness, and amount of 
dip in this region of the several formations penetrated, — items 
heretofore but vaguely known from surface observations. 
I. Jamestown Well Section. 
CHEMUNG GROUP. 
(A). The Conglomerate. — "Bed rock," according to the well 
record,* was encountered at a depth of 220 feet below the surfacef. 
The sample from this point consists of very finely pulverized 
milky quartz, derived without doubt from a large, hard boulder. 
One foot below, a tj'pical upper Devonian conglomerate appears. 
Tli is at first is composed most exclusively of quartz pebbles, 
ranging in size from a pea downwards. In color, they are white, 
rose, or yellowish ; in form, angular or sub-spherical. Presently 
a finegrained sandstone makes its appearance, forming a matrix, 
as it were, for the coarse quartz pebbles. This is of a light, 
bluish-gray color, is slightl}' micaceous and argillaceous, and at a 
depth of 240 feet, constitutes about 60 per cent, of the rock 
material. Seventeen feet lower still, few pebbles appear. The 
total thickness of the conglomerate is therefore not less than 30 
feet. 
By referring to plate IV, it will be seen that the upper surface 
of this formation is 1105 feet A. T. , or, as shown in the footnote 
below, about 660 feet stratigraphically below the Panama con- 
glomerate. X 
*Kept by Mr. W. R. Reynolds of Jamestown, N. Y., through whose 
kindness the writer was enabled to examine the samples. 
fThe mouth of the well has been estimated to be 4 feet above the R. 
R. station, i. e. 1325 feet A. T. See Bulletin No. 5, U. S. Geological 
•Survey, p. 211. 
JThis result is obtained in the following manner: (The altitudes A. 
T. are mainly from Carll's Rept. IIII. 1883, 2d Geol. Surv. Penna.) 
Altitude, Pope Hollow eongl. (up. sur.jat P.H.. .1940 feet A. T. (p. L81) 
" " " " at McCoy's 
6 miles south-southwest of Pope Hollow 1800 feet A. T. (p. 20G) 
Difference 140 feet. 
Hence, rate of dip along this line =23+feet per mile. Produce this 
line 4 miles to "A" (see PI. m). Here the horizon of the Pope Hollow 
congl. should have an elevation of 2032-f ft. A. T. This less L90 feel 
