DARTON.] VIRGINIA. 177 
Wells along the Potomac River. — (See also section 1 of PI. XVI). The 
wells in the line extending with frequent intervals from Coles Point to 
Fairport all appear to draw their waters from the basal Chesapeake 
beds, or the same horizon as in the wells on the Rappahannock side 
of the peninsula and in the group of wells across the Potomac River 
in Maryland. At Coles Point the water is at a depth of 220 feet, and 
the depths gradually increase to Fairport, where the well is 393J feet 
deep. The water is in good supply, and rises to about 12 feet above 
tide level. 
Only scanty data have been secured as to the records of this group 
of wells. At Cowart the following are reported: 
Feet. 
' 0-50 sand and gravel. 
50-250 fullers' earth. 
250-288 porous rock, with sand beds bearing water. 
At Fairport there are reported : 
Feet. 
0-70 sand and mud. 
70-370 blue clay or fuller's earth. 
370-393 quicksand. 
At Colonial Beach the Chesapeake water horizon is only a few feet 
below the surface, and the wells penetrate to basal and mid Pamunkey 
horizons, which are found at depths of 250 and 160 feet respectively. 
At Quantico there is a flowing well which has a depth said to be 210 
feet in which the water supply is probably from the basal beds of the 
Potomac formation. A record of the beds furnished by the engineer 
of the Pennsylvania Railroad Company is as follows: 
Feet. 
0-22 white clay. 
22-28 fine gravel. 
28-53 red clay. 
53-58 fine red sand. 
58-86 very hard blue clay. 
86-89 fine sand. 
89-124 dark clay. 
124-127 coarse dark sand. 
127-205 light-colored clay. 
205-210 very coarse sand and water. 
About 5 miles north of Quantico, near Possums Nose, a well was 
bored at the projected town of Barrow. Its depth was 195 feet, and a 
large supply of water was reported at 143 feet. 
Its record, kindly furnished by Mr. R. P. Hughes, of Washington, is 
as follows : 
Feet. 
0-10 clay and marl. 
10-20 gravel. 
20-30 clay. 
Bull. 138 12 
