DARTON.] 
DELAWARE. 123 
Lewes, Sussex County. — This well was bored in 1892 at the quaran- 
tine station, at an elevation of about 7 feet. Its bore is 6 inches and 
its depth 400 feet. The water rises to about the surface. In one day 
22,000 gallons were pumped, lowering the water level 55 feet, but it 
soon rose again when the pump was stopped. The following record is 
given : 
Feet. 
0-90 ordinary beach sand. 
90-100 yellowish gravel, medium coarse. 
100-300 gray sands and sandy clays, with a fragment of cedar at 200 
feet. 
300-330 bine tenacious clay, mixed with about 30 per cent of pebbles. 
330-392 similar blue clay and alternations of sand. 
392-400 sand and water lying on rock. 
The beds are Chesapeake below the yellowish gravel, and are thought 
to be above the great diatomaceous bed. 1 It is probable that the hori- 
zon is the same as that at Milford at 150 and 160 feet, as suggested in 
section 1, PI. YI. 
Wilmington. — The deep wells in Wilmington are bored in the crystal- 
line rocks, and the water supplies appear to be satisfactory. 
WATER HORIZONS IN DELAWARE. 
As relatively few deep wells have been bored in Delaware, the water 
horizons have not been fully explored over a very wide area. The well 
at Middletown has obtained a fine supply of water from the Potomac 
formation, apparently in the basal beds, and it is probable that this 
water sheet will be found to extend from Wilmington past Middletown 
far to the southward. At Farnhurst it yields a moderate supply. The 
dip of the horizon to the south-southeast is about 30 feet to the mile, 
which carries it from the tide level at Wilmington to a depth of 165 feet 
at Farnhurst and 535 feet at Middletown. Water horizons above the 
lower beds of the Potomac formation and in the Matawan, Eedbank, 
and Lower Marl that occur in New Jersey were not reported in the 
Middletown well, which probably indicates that these waters do not 
extend into Delaware. The principal Chesapeake horizons appear to 
be represented in Delaware, although the evidence in regard to their 
correlation is not conclusive. The basal Chesapeake water, so impor- 
tant in Maryland, has not been reached by the wells. The water from 
sands in the great diatom bed (the 525-foot horizon at Atlantic City) 
probably supplies the Dover and Mahon Kiver wells with their large 
yields, while Milford and Lewes apparently obtain their waters from 
just above the diatom bed. As the Kitts Hummock well draws from a 
bed about 125 feet above the Dover and Mahon waters, its horizon can 
not be definitely correlated with any of those at Atlantic City. The 
Ocean City well in Maryland is a high Chesapeake horizon which proba- 
bly extends into the southern edge of Delaware, but no wells have yet 
been sunk to it in that State. 
1 Woolman, report of geologist of New Jersey for 1893, p. 404. 
