Notes on the elasticity of the Lloyd sand on Long Island, New York

Abstract

The Lloyd sand is a productive artesian aquifer underlying all of Long Island except the westernmost part. It rests unconformably upon a floor of crystalline rock that slopes toward the southeast at about 100 feet to the mile. Locally the bed‐rock surface has a relief of more than 100 feet. The Lloyd sand consists of white quartz‐sand and gravel, with some layers of clay. It is considered to be part of the Raritan—the basal formation of the Upper Cretaceous series. At Rockaway Park, on the south shore of the Island, the Lloyd is about 200 feet thick and is overlain by 300 feet of clays of Raritan age. The Raritan clays are in turn overlain by about 150 feet of sands, believed to be of Magothy age, and about 315 feet of Pleistocene sediments.