Other wells at Federalsburg varying in depth from 133 to 185 feet find flows in higher beds of the Calvert. The Federalsburg wells with their various depths are a striking demonstration of the richness of the Calvert formation in water beds.

The Eocene water is reported from only two localities in Caroline County, but it probably underlies the whole county at depths of from 200 to 500 feet. The wells at Greensboro and Denton strike the characteristic hard water at depths of 240 to 285 feet. These wells have a small flow dependent on the elevation of the mouth of the well. The first city well at Denton was a non-flowing well, the second one was drilled down. near the river and it flows. The wells at West Denton, 350 and 400 feet deep, indicate a second Eocene level. The shallower well flows 120 gallons a minute, while in the second one the water stands within 20 feet of the surface. These two wells and the city wells at Denton noted above show the control of elevation upon the head of water in a well and they clearly demonstrate the basic falseness of a classification which makes flowage the criterion of an "artesian" well.

A well at Hillsboro 440 feet deep has a -22 head of good water. At 300 feet the well passed through "gunpowder material" (Eocene) and is probably drawing from a bed in the uppermost Matawan. This is the only well in the county that gets so low in the column.

Caroline County has a large supply of artesian water in the Calvert and Eocene beds, and by locating on low land the wells should be made to flow. However, the water should everywhere rise within easy pumping distance.

Non-Artesian Waters

SPRINGS. The flat nature of the country has not been favorable for the formation of springs and they are practically absent throughout the county, making it necessary for the inhabitants to rely upon wells for domestic and farm purposes.

SHALLOW WELLS.-The shallow wells of Caroline County draw their supply from the surface waters of the Pleistocene sands and gravels, and since the Talbot is only represented in a few areas along the larger streams

....

Surface Ample Hard 1903
Surface

most of the water comes from the base of the Wicomico. The Wicomico has a much larger surface exposure and hence contains more water. The common depth for shallow wells is from 15 to 30 feet and usually the water is of good quality, but local pollution by inhabitants or by drainage from some of the numerous swamps may render the water unfit for use or impart a disagreeable marshy taste or odor. At Federalsburg and at several other points the shallow water contains iron which is in the form of a colloidal hydrate, especially noticeable if a vessel of water is left standing for some time.

The shallow wells commonly supply enough water for household or farm uses and occasionally two or three such wells will furnish enough water for a canning factory. At Preston the usual depth for wells is 45 feet, the water being reported from a coarse yellow sand. This is the maximum depth for Pleistocene water in this county. The most widespread type is the dug well, so common during the early history of the region, but in many localities this type is being replaced by wells constructed by driving a pipe of small diameter into the ground. In some places the driven wells draw from the same water horizons as the shallow wells, but locally they reach deeper water-bearing beds. The driven well is generally superior to the dug well because the casing is better adapted for excluding impure surface waters.

TALBOT COUNTY

Talbot, lying between Queen Anne's on the north, Caroline on the east and south, and Chesapeake Bay on the west, is centrally located on the Eastern Shore. It is a region of low.relief, no part rising above 65 feet above sea level. The streams are tidal estuaries and the surface is but little dissected by erosion and is consequently a gently undulating, broad, flat, fertile plain.

GEOLOGY

The surface of the county consists almost entirely of the two latest Pleistocene terrace plains, the Wicomico occupying the eastern half of the county and lying at an altitude of from 40 to 60 feet. This is separated from the lower-lying Talbot plain, which occupies the western half of the

county, by an escarpment or steep slope extending in a north and south direction from Wye Mills to near Chancellor Point on the Choptank River. Beneath these surficial formations of loam, sand, and gravel are the Choptank and Calvert formations of the Miocene. These outcrop in limited areas in the stream valleys and comprise clays, sands, and marls. These are in turn underlain by the Eocene which is an important water horizon but does not reach the surface on the Eastern Shore south of Kent County. The Eocene is in turn underlain by the deeply buried formations of the Cretaceous.

The surface streams of Talbot County are not important sources of supply because the large streams are all tidal and either salt or brackish, and the small streams contain very little water in dry weather. The streams all receive drainage from inhabited areas and are of doubtful sanitary character. The conditions enumerated have prevented the use of surface water and there is no prospect of its future development.

UNDERGROUND WATERS
Artesian Waters

Attempts to procure artesian water in Talbot County have been uniformly successful, but flowing wells have been obtained only where the surface is less than 20 feet above sea level. The deepest artesian well in the

county is the 1015-foot well at the Easton Water Works, and the shallowest is a 29-foot well at Copperville. This well is discussed by Miller,' who believes that" although the well was not driven below the Pleistocene deposits the water probably comes from a greater depth and finds its way to the base of the pipe through some deep-seated fissure in the Calvert strata." The flow of the well is very small and the water is highly charged with iron, a feature not usual with the Calvert waters, but which has probably been acquired in this case through the passage of the water through the Pleistocene gravels.

The Miocene deposits are represented in this county by the Choptank formation which outcrops in some of the stream beds in the southern part of the county, and by the Calvert formation which is seen at the surface at a few places in the northern part along Wye River and its tributaries. The Choptank formation is not important as a water-bearing horizon, but the Calvert water has long been known and utilized. This water is soft and very good. An analysis of the water from the 135-foot wells at Easton is given on a subsequent page. The Calvert water levels are incapable of as close correlation as in the neighboring counties due to the horizontal gradation of the materials. The Calvert wells vary in depth from 166 to 195 feet. A well at Cordova, about 40 feet above sea level, is 116 feet deep with the water within 8 feet of the surface. At Easton the Calvert long. supplied the city with its water, the water bed being reached at 104 to 135 feet. These wells all flowed originally, but when the deep well was sunk the water in the shallower wells fell to - 10 feet and would furnish no water while the 10-inch well was being pumped.

Two wells at Grubin Neck, 160 and 186 feet deep, draw from the Calvert horizon but do not flow, and at Windy Hill a well 180 feet deep has a small flow of water from the same stratum.

Two horizons have been recognized in the Eocene, one at the base of the Aquia and one at or below the base of the Nanjemoy. The basal Aquia water is in use at only three localities, while the Nanjemoy wells are more scattered.

1

1 Miller, B. L. Geologic Atlas of the U. S., U. S. Geol. Survey, Choptank Folio No. 182, 1912, p. 8.