164 SURFACE GEOLOGY. 
wells to be principally composed of modified drift, a large part of which 
is clay.* On its south side the surface is gravel, with few boulders, none 
of which exceed 4 or 5 feet in diameter. 
The last of these kame-like deposits which remains to be described 
within the limits of Piscataqua basin, is the extensive plain of Newington 
and the north-west part of Portsmouth. This is three miles long from 
north to south, and for most of this distance averages a mile in width, 
forming a plateau 60 to 100 feet above Great bay and Piscataqua river 
on each side. Outcropping ledges and scattered boulders are seen in 
many places upon its surface; but numerous wells show only modified 
drift to depths of 30 or 40 feet, being first coarse gravel, 3 to ro feet in 
thickness, succeeded below by interstratified fine gravel and sand. The 
entire western edge of this deposit is a gently sloping escarpment, which 
descends Io to 30 feet. On the north and east it rests mainly on ledges, 
but at one place falls in an abrupt slope more than 50 feet. A section 
at its base in the north part of Newington showed sand overlain by gray 
clay, as at Dover. Southward, near the Concord & Portsmouth Railroad, 
its surface is sand, obliquely stratified. Between this and the Eastern 
Railroad it is changed to a broad ridge, 25 to 30 feet high, composed 
mostly of pebbles six inches to a foot in diameter, packed as compactly 
as possible with no layers of sand. This gravel is finely exposed in an 
excavation, from which it is teamed two miles for repairing streets in 
Portsmouth. The deposit terminates south-east from the Eastern Rail- 
road in a small plain of horizontally stratified sand. 
Exeter River and the Plains at Kingston and southward. The prin- 
cipal part of Exeter village, and several square miles bordering Exeter 
* The following are sections of wells upon this hill, noted in order from north-west to south-east : 
1. A well dug three years ago at C. C. Barton’s, about 30 feet below the top of the hill, showed till on the sur- 
face, 4 feet; gray clay, plainly stratified and sandy in some layers, but containing occasional pebbles seldom 
more than 6 inches in diameter, 38 feet; clear sand, with water, 1 foot; blue clay, 9 feet, extending lower ;—total 
depth, 52 feet. 
2. The former well here, about 150 feet distant to the south-west and nearly the same in height, was through 
till, 4 feet; gray clay, as in new well, 4 feet; sand and fine gravel, 15 feet; gray clay, 27 feet;—total depth, 50 
feet. The last eight feet were bored, and at the bottom the auger “ fell,’’ and a powerful flow of water came up. 
3. At A. Wiggin’s, near the top of the hill, a well 52 feet deep through unknown material becomes dry in sum- 
mer, and was recently bored 12 feet lower through sand without striking ledge ;—total depth, 64 feet. 
4. At E. F. Wiggin’s, perhaps 30 feet below the last place, the order was till containing boulders up to 500 pounds 
in weight, with layers of gravel and sand, 20 feet; interstratified fine gravel, sand, and clay, 20 feet; very com- 
pact gray clay, nearly free from rock fragments, 16 feet, underlain by quicksand with abundant water ;—total 
depth, 56 feet. 
5. A well dug two years ago at T. E. Marston’s, about 20 feet lower than the last, passed through coarse water- 
worn gravel, with the largest stones 1} feet in diameter, 8 feet; sand and fine gravel, 10 feet; gray clay, stratified 
and containing layers of sand, 20 feet ;—total depth, 38 feet. 
