90 W. Upham—Terminal Moraines 
formations overlain by drift in sea-cliffs, thirty to fifty feet 
high, at its southeast shore. Here in a distance of a sixth of a 
mile the lower strata rise in two anticlinals, which dip at angles 
varying from 10° to 45°. They consist of dull-red, brown, 
dark and black clays, and brown, yellow and white sands. 
These arched strata are overlain conformably by yellow sand 
and fine gravel, which farther east are interstratified with lay- 
ers of white and dark gray sand and dark clay. About 800 
feet east from the northeast anticlinal, these later beds dip 5° 
underlain a little to the west by a compact ferruginous layer 
one foot thick, which separates it from white sand; overlain oy 
six feet of lighter colored sand, its upper portion filled wit 
shells* for two or three rods, at a height which varies with the 
slope from 12 to 20 feet above sea; next, 10 feet of dark clay, 
which thins out at 100 feet to the west, but increases in thick 
ess to the east; then, about 8 feet of coarse gravel, with angu- 
lar pebbles to 1} feet in size, becoming coarser 150 feet to the 
west, where it holds angular bowlders 4 feet in diameter, these 
covered by about 10 feet of sand; which also forms the top of 
this section, resting on the gravel to a thickness of about 8 feet. 
The coarse gravel and overlying sand appear to be glacial 
deposits, and these, frequently with numerous and large bowl- 
ders, form the surface of the island, rising in hills 125 feet 
high. The shell-bed belongs to a period immediately preced- 
ing the ice age, in which the sea here had about the same tem- 
perature as now. The variously colored anticlinal strata are 
older than this, but yield no fossils. They are probably of the 
same date with similar clays on the northeast side of the same 
island, on the south side of Montauk a mile west from the 
point, and at Bethpage; as also with the lower portion of the 
cliffs near Brown’s Point.+ Further exploration is needed to 
compare these with the lignitic beds of Block Island and the 
upturned Tertiary strata of Gay Head. 
North of the extreme terminal moraine on Long Island, 
another series of plains of gravel and sand, varying from one 
mile to five miles in width, and of similar height and south- 
ward slope with those on its opposite side, extends from Syos- 
set forty-five miles eastward to Riverhead, and thence con- 
tinues along the north branch of the island nearly thirty miles 
more to Orient Point. The description of these plains belongs 
*The fossils of this place were described by Mr. Sanderson Smith, in the 
Annals of the Lyceum of Natural History of New York, vol. viii, p. 149. See 
I ve species are enumerated, all of 
which, excepting one or two of more northern range, are now found living in 
+ Figured by Mather in the Geological Report of the First District of New 
York, Plate iv. 
