\ 
The Ice-SIieef i/i X<i rr(i(i((nscff licji. — ]\ ood irorfJi . 1155 
Later Stages of the Kktreat. 
The next three frontal stages are altogether on the Provi- 
dence atlas sheet and are ])lainly indicated by the topography 
as expressed in the contour lines. 
the uobin hile stage. 
The narrows of the Providence river south of the city of 
Providence are formed by the hills of stratified drift of whicli 
liobin hill is the culminating point. These deposits attain an 
elevation over 100 feet above the sea and range in an east- 
west direction for about a mile and a half, with a breadth 
<?xceeding one-half mile. Throughout where cuts have been 
made in laying out streets, the deposits show stratification, 
much of which has been displaced by settling, evidently 
brought about by the melting out of buried ice. South of the 
deposit stretches the P^lmwood sand-plain, which declines 
southward to the Pawtuxet river. The high morainal head 
and low overwash frontal plain are conspicuous features of 
the west side of the bay as seen from a passing vessel. On the 
east side of the bay, at India point, there are traces of the 
same deposits, but they are nowhere so well developed. West- 
ward of Robin hill the frontal conditions merge into the 
JMashapaug pond area, where the front cannot be well traced 
THE FOUT HIEL SUB-STAGE. 
Fort hill, at Fox point, exhiliits a thick section of water- 
worn but ill-assorted drift of a morainal type, sharply sepa- 
rated above from a superficial coating of stratified drift 
varying from nothing to five or six feet in thickness. South- 
ward from the old fort there is a sand-plain, showing that 
tlie ice-front for a time rested against the east bank of the 
mouth of Seekonk river at this point. Frontal conditions are 
iilso indicated on the west side of Providence river in this 
same belt b}" the stee]) northern slopes of the sand-plain in the 
vicinity of the Rhode Ishtnd Hospital. 
(EXTKAE falls STAGE. 
This stage of ice retreat is intlicated by the remarkably 
well developed sand-jjlain. esker, and lateral terraces, north- 
west of the city of Pawtucket. The contours of the Provi- 
dence atlas sheet bring out in a clear manner the essential 
features of these interesting deposits. The head of the sand- 
l)lain marks the southern limit of the ice in tlie Hlackstono 
