34:6 JSTew Yoek at the World's Columbian Exposition. 



ing deltas. It has been suggested by Dr. F. J. H. Merrill that the 

 change in the estuary deposits was due to an elevation of the land, thus 

 exposing an area around the basin which would afford more siliceous 

 matter. 



The clays of .the Champlain valley are estuary formations of the 

 same age as tlie Hudson river clays. They underlie the terraces along 

 the lake, which have been elevated to a height of 300 or more feet 

 above the lake's surface. These terraces may be traced almost continu- 

 ously from Whitehall, at the head of the lake, to its northern end and 

 beyond, but on account of the extensive erosion that has taken place 

 they are usually narrow, and it is only at sheltered points like Port 

 Kent and Beaufort that they are specially prominent. The section 

 involved is yellowish brown sand, yellowish brown clay and stiff blue 

 clay, the latter being rather calcareous, while the upper clay is 

 somewhat siliceous. 



Long Island Clays. 



The clay beds are exposed along the north shore of the island and at 

 several points on the main line of the Long Island railroad. With the 

 exception of four similar deposits on the north shore all the clay beds 

 are rather unique in appearance. The most western clay outcrop on 

 Long Island of which we have any knowledge is on Elm Point. There 

 is here a bed of stoneware clay thirty to forty feet thick and overlain 

 by iifteen to twenty feet of yellow gravel and drift. The clay is of a 

 dark gray color and contains streaks of lignite. The deposit will no 

 doubt prove to be of Cretaceous age. 



Another outcrop of clay of high quality is at Glen Cove in Hemp- 

 stead harbor, and has long been known to be of Cretaceous age. The 

 layers are blue, red, black and yellow and dijJ north ten to fifteen degrees. 

 Near this locality and on the shore of Mosquito Inlet is an outcrop of 

 pinkish clay, used for lire brick and stoneware. Dipping under it to 

 the east is a bed of alternating layers of clay and quartz pebbles, the 

 latter in layers from four inches to one foot in thickness. Associated 

 with this is a bed of kaolin, but the exact relations of the two deposits 

 are not known. Kaolin also outcrops from under the gravels on the 

 west shore of Hempstead harbor. 



On Centre Island in Oyster Bay we find the most western outcrop 

 of a number of clay beds which are very similar ; the others are at 

 East Neck, Fresh Pond and Fisher Island. The clay on Centre Island 

 is of two kinds, a lower bluish clay and an upper brown sandy clay. 

 Overlying this latter is a stratified sand used for tempering and mold- 

 ing. White fire clay is also said to occur on Centre Island. At Jones' 

 brickyard on the east shore of Cold Spring liarbor is a thick deposit of 

 clay. The lower portion is tough and contains little sand. The upper 

 portion is more sandy and of a brown color. The clay bank is over 

 100 feet high. 



There is a deposit of fire clay and stoneware clay at Little Neck near 

 Northport. It is of yellowish white and blue in color and stratified, 

 the layers_ being separated by thin sheets of sand. Overlying the clay 

 is a deposit of sandy kaolin. The outcrop' is of Cretaceous age. Sev- 



