.... Soft rock (glauconite with a little sand and gravel). A little ..130-155 Monmouth. Hard black earth (dark clay with much glauconite, a little ..155-340 Hard dark sand (glauconite with coarse sand and bits of .340-360 Matawan. Hard dark sand (less glauconite and more grains of brownish ......360-380 In the original grouping of the materials the Monmouth was omitted, but in view of the fact that the Monmouth at its outcrops is known to be distinctly marine in origin its absence here would be hard to explain. The above log contains several points of interest. The hard sandy clay at 130 feet is the same as the "sand rock" encountered on Long Point at 195 feet, while the water at 155 feet is probably the same as that found at the "Anchorage" at 265 feet. The main water level, besides supplying the wells at Sherwood, of depths around 365 feet, and those near McDaniels, 340 to 380 feet, is found also in the well at Tunis Mills, 437 feet deep, where the water was originally so alkaline that it foamed in the boilers. Another well drawing from the same level is located about 11⁄2 miles west, and the following materials were penetrated in the course of drilling: Soft yellow clay... Sand rock, blue. Soft blue clay... Hard blue rock.. Soft green sand... Soft blue clay... Soft sandy black clay. Gravel Feet 0-15 15-65 65-86 86-179 179-181 181-190 190-250 250-298 298-301 .301,7-425 Soft sandy black clay. Hard blue clay ?..... 425-559 559-590 These wells all flow, although the amount is not very large, the maximum reported being 20 gallons per minute. At Easton this horizon was encountered at 570 to 600 feet, and at Oxford two wells 540 feet deep have flows of 25 gallons per minute from the same stream. The well at Claiborne 444 feet deep was referred by Darton' in 1896 to the Magothy, and Miller in the recent Choptank folio (1912, Bull. U. S. Geol. Survey No. 182, p. 8) reassigns it to the Magothy along with the 540-foot well at Oxford. The Claiborne well and the 486-foot well at Tunis are here thought to be possibly Magothy, but the Oxford wells are quite certainly no lower than the upper Matawan. To correlate the Oxford wells with that at Claiborne would require that the dip be less than 10 feet in the mile, which is not at all in accordance with observation at the outcrops nor with the experience in wells. The well at Tunis is about 14 miles down the dip from the Claiborne well and the difference in depth after correction for elevation is 40 feet. This would give a dip of about 25 feet in the mile, which is exactly the average dip of the beds at their outcrop. The Easton well, the log of which is appended, was sunk with the object of augmenting the supply drawn from the shallow wells in the Calvert. Light gray sand, water bearing, containing shark teeth, shells, large pieces of bone. Pumps 120 gallons per minute and heads up to -10 feet 2 104-135 1 Darton, N. H. Bull. U. S. Geol. Survey No. 138, 1896, p. 133. 'During about 1885 when the Water Works were installed, six 4-inch wells were put down to this same stratum, all of which flowed at that time. When the 10-inch well was sunk it was found that the water only rose to within 10 feet of the ground, and that the smaller wells would furnish no water when the large one was being pumped. Sand and gravel, yellow white and black, water bearing. Pumps White clay or marl, with hard and soft streaks, containing shells The well passed through the Calvert water horizon, the upper Matawan level at 570 to 600 feet, and is drawing from the main stream of the Magothy. It should be stated here that when Darton and Miller spoke of the Potomac waters they included the Raritan which they probably thought was the horizon of this well, and it has only been recently that the Raritan has been assigned to its proper place at the base of the Upper Cretaceous. With this in mind, Miller's reference of the Easton well to the Potomac group is not so much at variance with the present assignment. In the above log the 80-foot thickness of "green clay, black specks may be too thick to be referred to the Nanjemoy, but the lithology is very strikingly like the clays of the Nanjemoy. There is possibly a division in this bed that was not noticed by the driller, which may also be true of the 180 feet of black sandy clay or marl at 390 to 570 feet, since some slight thickness of Monmouth probably occurs. The bed of " yellow clayey sand " at 802 to 835 feet may be the level that supplies the wells at Claiborne and Tunis Mills. The water from the white sand is plentiful and strongly alkaline. It is satisfactory for use when mixed with that from the shallow wells, but has not been tried alone. This Magothy stream is the largest one that has been encountered in the county thus far. The Patuxent water level is probably more than 1000 feet below the Magothy and should yield large flows of water which, however, would probably be highly mineralized. The Magothy beds dip about 30 feet in the mile to the southeast, so that, with the Easton well for a guide, other localities can judge its depth. After the Magothy, the next horizon in importance is the one in the upper Matawan, that which is shown in the Easton well at 570 to 600 feet, and on Tilghmans Island at a little less than 400 feet. This bed dips to the southeast at about 25 feet to the mile, so that with the Tunis Mills, Oxford, and Easton wells for guides, it too may be easily located. After these two come the Eocene and Calvert horizons which have so far never failed to yield water, although the quantity and quality have not always been satisfactory. Non-Artesian Waters SPRINGS.-Springs are practically absent in the low-lying country throughout the central and southern Eastern Shore, and there are no true springs in Talbot County other than local seepages and these should not be used for domestic purposes since they are uncertain in amount of water furnished and especially liable to contamination. |