130 ARTESIAN WELLS ON THE ATLANTIC COAST. [bull. 138. 
Fee.. 
620 sand, fine, greenish gray. 
630 clay, sandy ; shell fragments. 
640-650 clay, light gray ; diatomaceous. 
660 clay, light brownish gray ; diatomaceous ; Anomia. 
670 clay, very sandy, dark greenish gray. 
675-690 clay, light greenish gray ; diatomaceous. 
700 clay, gray, sandy. 
710 clay, light gray ; diatomaceous. 
720 sand, fine, greenish gray ; large glauconite grains. 
740 diatomaceous clay, dark buff. 
750 diatomaceous clay, light gray. 
760 diatomaceous clay, darker. 
770 sand, fine, greenish gray ; some glauconite. 
771-775 rock, with large grains of glauconite. 
780-850 argillaceous sand, dark olive green, with large proportion 
of glauconite; coarser grained at 820; finer at 800; few 
small quartz pebbles and a shell fragment (oyster) at 810. 
855-950 clay, very light greenish gray ; shell (sp ?) at 932. 
955 clay, slightly micaceous. 
960 clay, more sandy, more micaceous. 
961-963 clay, brownish gray, sandy, micaceous, with plant frag- 
ments of Severn aspect. 
965 sand, fine, gray, some mica. 
970 clay, black, with pyrite fragments. 
971-972 clay, very compact, light gray. 
974-1, 005 sand, fine, micaceous, coarser below ; lignite at 990. 
1, 005-1 , 015 clay, brownish gray, tough. 
1, 015-1, 025 sand, fine, gray. 
1,025 sand, moderately fine, gray, micaceous. 
1,033-1,040 clay, bluish gray, with reddish streaks. 
1, 042-1, 052 sand, moderately coarse, gray, with some mica ; water. 
1, 052-1, 064 clay and sands, gray, sandy, with reddish streaks. 
1, 064 clay, light gray, very compact. 
The upper members in this record are typical Chesapeake deposits, 
but the lower members are not clearly identified. Dr. Wm. H. Dall 
examined the shell fragments, and states that from 60 to 230 feet the 
St. Mary's fauna of the Chesapeake formation is well characterized. 
The diatomaceous beds begin at about 380 feet below the surface and 
extend to 760 feet. The rock at 771-775 feet appears to be at the base 
of the Chesapeake formation, as it occurs in wells and outcrops to the 
north and west, and the highly glauconitic sands or marls below are 
probably Pamunkey in age. The shell at 932 feet was a worn fragment 
of which the species could not be determined by Mr. T. W. Stanton, 
who kindly studied it for me. I received a large mass of clay from 
961 to 963 feet, brought up in the valve space of the sand bucket, and 
as it showed fragments of plant remains I requested Mr. L. F. Ward, of 
the Geological Survey, to examine it. He found the organic materials 
too fragmentary for identification, and could give no opinion as to its 
age. From the aspect of the clay I am strongly inclined to refer it to 
the Severn formation, of which also the black pyritiferous clay at 970 
feet would be quite characteristic. The water-bearing sands which 
extend from 974 to 1,033 feet are thought to be the Magothy formation. 
