Pre-Kansan and Iowan Deposits. — Fuller. 309 
Cretaceous surface having a probable relief of several hundred 
feet. During their deposition the land was submerged to the 
300 to 360 foot level, to which hight the gravels accumulated 
with a rather flat upper surface. The deposition is believed to 
have taken place when an ice sheet existed not far to the north, 
and furnished considerable amounts of granitic materials. Fol- 
lowing the deposition the gravels were uplifted and eroded un- 
til only an occasional remnant on the crest or slopes of the Cre- 
taceous uplands remained. Outcrops can, however, be seen at 
a number of points along the north shore and in the Wheatley, 
West, and Half Hollow hills, and can be recognized in well 
borings at many points. This gravel has not previously been 
recognized on the Island, the yellow gravel of Merrill, 1 Hol- 
lick, 2 Crosby, 3 and Woodworth 4 all belonging to the Manhas- 
set or later deposits. It has, however, been recognized at mam- 
points by the writer and associates, and can be mapped both 
at the surface and beneath the later drifts over considerable 
areas. Special examinations by Mr. G. N. Knapp of the New 
Jersey Geological Survey in company with the writer, served 
to establish its probable identity with the Pensauken of north- 
ern New Jersey, with which it agrees closely in composition, 
weathering, altitude, relation to the Cretaceous, and in sub- 
sequent erosion. Because of the marked weathering of its ma- 
terials, which is much greater than that shown even by the 
Kansan of the Mississippi valley, and because of its deposition 
during the first recorded advance of the ice, it has been assigned 
to the Pre-Kansan or to the Kansan glacial stage, probably the 
former. It would seem from descriptions to correspond with 
McGee's high level Columbia beds of New Jersey and south- 
ward. 5 It is believed to be probably contemporaneous with the 
Carmichael clays of the Monongahela" terraces' 1 and with the 
terrace gravels of the Lower Allegheny river in western Penn 
sylvania. The exact relation to the old extra-morainic drift of 
New Jersey and Pennsylvania has not yet been worked out. 
The next succeeding gravel definitely recognizable in the 
surface exposures of the Island is the Manhasset gravel, first 
described in detail by Woodworth. 7 This is separated from the 
Pensauken by the immense erosion interval mentioned, during 
which all but an occasional patch of the latter was removed and 
by the periods of deposition noted on a subsequent page. The 
