410 THE COASTAL PLAIN OF NORTH CAROLINA.

HALIFAX COUNTY.

Topography.—No part of the county is covered with topographic
maps, and an accurate statement of the surface features is impossible.
The Chowan terrace plain of the Pleistocene borders Roanoke River,
with elevations not exceeding 50 or 60 feet; a considerable portion of
the eastern part of the county is covered by the next higher or Wicom-
ico plain, with elevations ranging from 80 to perhaps 100 feet, being
separated from the Chowan plain by a well-marked scarp; in the
eentral part of the county the Sunderland plain exists, but its ex-
tent is not known; and a narrow strip of the Coharie plain is probably
present to the west of the Sunderland area. The western part of the
county falls within the Piedmont region and presents a Piedmont
topography, although deposits of Lafayette age are present to greater
or lesser extent as surficial coverings.

Geology.—Crystalline rocks form much of the surface in the western
part of the county, reaching elevations of perhaps 400 or 500 feet. To
the eastward the surface of the crystallines passes beneath the deposits
of the Coastal Plain, forming their basement, and in the extreme east
probably exist at a depth of about 400 feet. In that part of the county
lying to the east of the main line of the Atlantic Coast Line Railroad

the Patuxent beds, consisting’ of compact clays and arkosic sands, are-

present, resting directly upon the eroded crystalline surface. These
reach a maximum thickness of perhaps 275 to 300 feet. Their upper
undulating surface was observed rising and falling above and below
water level in Roanoke River from the State farm to Palmyra, the
maximum thickness exposed being about 12 feet. Resting upon the lat-
ter are the sands, clays, and marls of the Miocene, having a maximum
thickness of perhaps 75 or 80 feet, and spreading westward beyond the
region of the Patuxent beds, overlapping and transgressing upon the
crystalline basement surface to an unknown distance, perhaps not ex-
ceeding a few miles west of the main line of the Atlantie Coast Line
Railroad. Over all older formations the Pleistocene sands, loams, and
gravels of the several terrace deposits are spread in a thin sheet, even
extending westward over the crystalline rocks. In the western part of
the county deposits of sand and gravel of Lafayette age mantle to
greater or lesser extent the Piedmont hills at elevations exceeding 230
feet above sea level.

Water Resources.—Over the eastern half of the county the drinking-
water is obtained principally from open and driven wells 15 to 50 feet
in depth, the water coming from the lower sandy portions of the Pleis-
focene, or in the deeper wells from sand beds in the Miocene. The

most common depth of the driven wells is about 30 feet. Where stream