418 
GEOLOGY OF THE FOURTH DISTRICT. 
where the boring was made, but at present the water does not rise to the surface. Gypsum 
was found at the depth of twenty-five feet, which continued at intervals for 100 feet; below 
this was found sandstone, and occasional hard layers of rock — towards the last, so hard that 
the drill gained only an inch per diem. They passed through a fissure at 100 feet. Salt or 
brackish water appeared at 170 feet. The lowest rocks were sandstone and slates. Inflam¬ 
mable air was discharged during the boring, and also subsequently. At the time of our visit, 
on shaking the wooden tube, a gurgling noise could be heard below ; and then upon passing 
down a burning paper, an explosion took place in the tube. No decided odor could be distin¬ 
guished. Doubtless this inflammable air was carburetted hydrogen, as it has been frequently 
noticed in the Western Stales in similar borings for salt. Messrs. Reese and Stowe were of 
the company who made the search, and from them we received the preceding account of the 
work ; the former gentleman presented us with the only sample he then possessed of the 
rocks penetrated during this boring, and which was extracted from the depth of 348 feet.. 
Clay . 
Clay, suitable for the manufacture of brick, occurs abundantly along the line of the canal, 
and in limited beds at several points near and north of the ridge. 
Gypseous Marl. 
Plaster marl (the local name) occurs at many points on the Erie canal, and extends south 
into the adjoining county of Ontario. It generally appears as a soft slaty rock, or as an in¬ 
durated marl, of an ash grey, and sometimes a greenish color. It is the gangue of the gyp¬ 
sum or plaster, in this, as well as in the neighboring counties. This marl generally contains 
an appreciable proportion of lime, although in some instances it is entirely argillaceous. Al¬ 
though of the nature of solid rock when first extracted, upon exposure to the air it slackens and 
crumbles down in a short time. We are not aware that it is used as a manure, but without 
doubt to sandy soils its addition would be very profitable, perhaps as much so as the plaster 
which it affords ; inasmuch as soils purely sandy require clay as well as lime to give them a 
proper character of composition. 
Near Clyde, the gypseous marl is seen of a dark, grey color, slaty structure, and contains 
marine fossils, among which are Orthocerae, Trilobites, and a variety of shells. 
At Lockville, one mile east of Newark, it occurs, greenish, reddish, and variegated, in the 
banks of the canal, and in various excavations, especially at a race-way from Price’s mill. 
At the latter place I examined and collected the marl. The greenish variety is amorphous, 
and contains gypsum in irregular or curious crystals. It effervesces with acids. Another 
variety is slaty, grey or ash color, soft, penetrated by numerous very thin seams of gypsum, 
and does not effervesce with acids. It appears to be entirely argillaceous, slackens upon ex¬ 
posure to air and moisture, and crumbles to a dry earthy powder. 
