The uppermost Cretaceous and lowermost Tertiary planktonic Foraminifera obtained from cores taken in a deep well near Dover, Delaware are studied. The Cretaceous foraminifers are of the Heterohelix-Globotruncana assemblage and are probably of late Maescrichtian age. The Danian Globorotalia compressa - Globigerinoides daubjergensis zone lies immediately above. The Cretaceous-Tertiary boundary is at a depth of approximately
980 feet and lies within a gray, glauconitic silt.
RI3 Wells for the Observation of Chloride and Water Levels in Aquifers that Cross the Chesapeake and Delaware Canal
Three test wells were drilled near the banks of the Chesapeake and Delaware Canal, in aquifers formed by sand beds in two geologic units, the nonmarine Cretaceous sediments and the Magothy formation, which crop out along the sides and across the bottom of the canal. The canal carries tidal flow from the Delaware River to and from Chesapeake Bay. The purpose of the wells was to determine whether salt water from the canal has entered the water-bearing beds of these formations, and to determine the head of water in them. It was found that the sands contain fresh water, uncontaminated, and that apparently there was discharge of fresh water from the aquifers to the canal under low head, at least from the winter of late 1955 through early autumn 1957.