238 2'he American Geologist. October, 1895 
ninth was that of glacial lake Iroquois; and the tenth is the present 
time. 
This paper was discussed by I. C. White, N. S. Shaler, J. W. 
Spencer, W. M. Davis, and H. S. Williams. 
The Geologu of Old Haiiipsliirc county in Massachusetts. B. K. Em- 
erson, Amherst, Mass. Twenty minutes were first given to a descrip- 
tion, with detailed maps, of the crystalline rocks which form the west- 
ern and eastern borders of the Connecticut valley, in which Springfield 
is situated, for the use of the members of the Society on excursions in 
the vicinity. 
Again, twenty minutes were occupied in a description of the Triassic 
strata of this valley and the history of their origin, involving the filling 
of the basin with sands and gravels, the outflow of trap and the erup- 
tion of ashes, closing with the formation of a series of small volcanic 
cones, and followed by the upfolding and erosion of the whole. This 
part of the paper was illustrated by maps and models. 
Lastly, in the third twenty minutes of the hour, the Glacial and Post- 
glacial history of the region was reviewed, with exhibition of detailed 
maps of the glacial lakes and river courses antedating and following the 
formation of the great series of lakes which occupied the present Con- 
necticut river valley, and maps of the later terraces formed in the old 
lake beds. The way in which the alluvial plains are made up of con- 
fluent islands was exijlained; and attention was directed to the distinc- 
tion between filled and unfilled lakes, the old Springfield lake having 
become filled, while the Hadley lake remained unfilled. The further 
facts were noted that ti'ibutaries run down directly across the old bot- 
tom of unfilled lakes, but when they come upon the broad terrace flat 
or meadow there appears a marked repulsion of the tributary from the 
main stream, so that they flow parallel with each other for long dis- 
tances, after which the affluent finally turns and enters the trunk river 
at right angles. This was explained by the formation of islands in the 
main stream off the mouth of the tributury, so that the latter had to 
flow around the islands down stream one after another, thus running 
parallel a long way before reaching its mouth. 
The luany oxbows and big bends of the Connecticut, and of its tribu- 
taries, across the bottom of unfilled lakes, were adduced as indications 
of the influence of the earth's rotation. 
Notes on the Relations of Loiver Members of the Coastal Plain Series 
in South Carolina. N. H. Darton, Washington, D. C. (Read by 
title.) The formations below the Eocene buhrstone, which were in- 
cluded in the Eocene by Tuomsy, have been found to be Potomac. 
Some of their features and their relations to the marine Cretaceous are 
described. 
Resume of general Stratigraphic Relations in the Atlantic Coastal 
Plain from New Jersey to South Carolina. N. H. Darton. (Read by 
title.) A series of sections was announced to accompany this paper, 
showing the distribution and variations of the principal coastal plain 
formations. 
