C. H. HITCHCOCK THE CONNECTICUT VALLEY GLACIER. 3 



The second paper presented was — 



ON THE DENTITION OF TITANICHTHYS AND ITS ALLIES 

 BY E. W. CLAYPOLE 



it 



On behalf of the Committee on Photographs Mr C. W. Hayes an- 

 nounced that the photographs recently acquired were displayed in the 

 adjoining hall of the University Geological Museum. 



The following paper was then read : 



STUDIES OF THE CONNECTICUT VALLEY GLACIER 

 BY C. II. HITCHCOCK 



Reference may be made firs! to the literature of the subject by Professor E. Hitch- 

 cock, who believed the Lee marks in general were produced by icebergs, and recog- 

 nized true glacial phenomena in the AVestfield and Deerfield river valleys tributary 

 to the Connecticut. This was in 1853. Ten years later Professor J. D. Dana com- 

 mented upon these and related farts, and presented the view that the markings 

 were not produced by Local glaciers, but were made by the general ice sheet, the 

 variation in direction having been due to pressure. Professor Louis Agassiz, in 

 1872, recognized local glaciers entirely subsequent to and independent of the main 

 ice sheet in a part of the White mountains. The present author has also recorded 

 similar views in various papers and reports. . 



A more thorough examination of the main Connecticut valley in the vicinity of 

 Hanover, New Hampshire, has recently been made in order to afford a better under- 

 standing of the facts. Over a territory thirty miles long and from ten to fifteen 

 miles wide nearly every 1 dge has been scrutinized, and the directions of stria? re- 

 corded. The record includes two bundled observations within this area. The 

 attempt was made to have this record exhaustive, and to include the markings 

 on both sides of the valley movement. The general conclusion is that two move- 

 ments are indicated: first, in the direction S. 30° E., principally on the highland 

 borders; secondly, in the direction S. 10° W., existing only in the depressed area. 

 More specific conclusions are the following: 



1. In addition to the Connecticut valley movement in the direction indicated by 

 the topography, there were numerous branches to it, corresponding to the smaller 

 tributaries. The phenomena observed authorizing this generalization are striation 

 and the transport of bowlders. The test cases are where the movement has been 

 in direct opposition to the general southeasterly current. Thus, on adjacent ledges 

 two miles north of Hanover, there are striae pointing X. 60° W.„and others S. 20° 

 W., the first being tributary to the second, and less deeply scored. Next, there 

 are a dozen excellent examples of the westerly transportation of large blocks of a 

 peculiar protogene-gneiss. These occur in Lebanon, Hanover and Oxford, and in 

 a few cases there are stria? to correspond, trending southwesterly. This particular 

 rock occurs only on tin- eastern side of the valley, and it is not possible, therefore, 

 to say that its fragments were transported by ice in the course S. .">0° E. 



2. Near the upper limit of the valley striations there are several examples of 

 the S. 30° E. course, which are isolated and situated in the midst of the S. 10° W. 



