The Ice-Sheet in. Xarragn nseft Ba(/. — Woodirorth. 153 
district a re-entrant angle in the front of the great ice-sheet, 
the position of which embayment is further marked by inter- 
lobate moraines of a bouldery nature extending northward 
along the western side of the bay essentially as was suggested 
by Chamberlin several years ago. Furthermore, the fact that 
the land for three miles north of point Judith is composed of 
glacial drift, mostly a dense blue clay, exceptionally gravelly 
and interpolated with stratified gravels, and having a low 
knob and basin topography, indicates the southward turning 
of the Charlestown moraine in this direction. 
THE SLOCUMVILLE STAGE. 
This stage of the ice-retreat is believed to be later than that 
of the Charlestown moraine. It is marked by a moraine ter- 
race extending from the west of Wickford Junction south- 
eastwardly along the northern base of C!ongdon hill, rising 
from 150 to 160 feet above sea level and from 60 to 100 feet 
above the low ground of intraglacial* drift at its base. From 
this moraine terrace or ice-contact slope an apron of sand and 
gravel stretches southwestward by Slocumville on the Shore 
Line railroad beyond the limits of the Narragansett Bay sheet. 
Southeastward from Congdon hill, where the ice- front rested 
against the cr^'^stalline escarpment of the western border of 
the Carboniferous basin, the moraine is not well defined. The 
road to the top ascends the crest of a short esker. An isolated 
patch of water-worn sand and gravel, beset with large boul- 
ders, on the ridge back of Saunderstown, R. I., is probably of 
morainal origin and marks the continuation of this moraine. 
Eastward of this point it has not been found. It is probable 
that the stand of the ice-front along this line was due to the 
resistance offered by the wall of the Carboniferous boundary. 
East of Saunderstown there is an open valley southward to 
the sea, which would have permitted the southward extension 
of the ice-front or tlie deposition of washed drift without 
high lying terraces. 
*Intraglacial (see Daua's Manual of Cieolopy, fourth ed., 1895, p. 958) 
is here used for drift deposited in the field occupied by the ice, in con- 
tradistinction to extraglacial drift which has come to rest on ground 
not actually covered by the ice when it was deposited. According to 
Prof. Dana's use of this term, however, it would he synonymous with 
englacial, as Prof. Chamberlin designates the drift enclosed in the 
lower part of the ice-sheet. 
