DAVIS: RIVER TERRACES IN NEW ENGLAND. oat 
IV. Observations of River Terraces in New England. 
VALLEY OF THE WESTFIELD River, Mass. Eastern Section. This 
branch of the Connecticut rises among the hard-rock Berkshire hills 
of western Massachusetts, the round remnants of the uplifted and 
dissected Cretaceous peneplain of the Appalachian province, and thence 
flows eastward part way across the broad valley lowland that has 
been excavated in the weaker Triassic formation during later Tertiary — 
time. Between the eastern base of the crystalline uplands and the 
ridge formed on the main sheet of extrusive trap within the Triassic 
area, the streain has excavated a fine series of terraces in the uncon- 
solidated drift deposits that have been so abundantly spread over the 
Triassic lowland by the Connecticut and its tributaries. 
The village of Westfield lies near the middle of this terrace system 
and serves to mark the separation of its unlike eastern and western di- 
visions. In the eastern division, Westfield river, re-enforced by Little 
river, a branch which leaves the hills two miles south of the main 
stream, has opened a broad basin at an elevation of about 140 feet. 
The basin floor is nearly everywhere enclosed by the strong scarp of a 
single high terrace whose plain stands at altitudes of 240 to 280 feet. 
The plain is not of simple origin. On the southeast, its surface is roll- 
ing, as if consisting of morainic and kame-like deposits. On the north, 
it is smooth and its sands are fine enough to have been raised in occa- 
sional dunes; here the plain falls off southwestward to the valley of 
Powdermill brook in a series of lobes, whose intermediate depressions 
are too large to have been excavated by local drainage : hence it is prob- 
able that this part of the plain is a delta front in one of the areas of dep- 
osition described by Emerson (650-653). South of the main basin, the 
smoother part of the high plain (Poverty plains) is regarded by Diller 
(265) as an extension of the plain on the north; the originally con- 
tinuous surface having been formed by the flooded Connecticut. West- 
ward up the Westfield valley, the high plain ascends towards the hills 
and is of much coarser materials than elsewhere ; this part seems to 
have been capped by the local outwash from the high ground during the 
period of aggradation. As the coarse upper gravels lie on fine sands 
and silts, this high plain is probably, like the one on the north, a delta 
surface, built up in standing water. 
The strong scarps, B, Figure a by which the high drift plains 
VOL. XXXVIII. —NO. 7. 
