494 PllOCEEDINGS OF THE NEW YOEK MEETING 



of building up of this deposit the reader is referred to Professor Russell's account 

 of the Malaspina glacier.* 



There are no lobes pointing downstream in the direction of ice and water move- 

 ment, as one would be led to expect from a study of New England sandplains ; f 

 but the position of all the eskers at the side of the valley indicates that the ice was 

 in the center of the valley, and if the waste was sufficient to fill in all the space 

 between the ice and the valley sides, as the deposit at the navy yard seems to show, 

 there would have been no chance for the formation of lobes. 



Although there are no lobes at the navy yard, the writer found several i)laces 

 along the river whei'e tributaries enter, which were not completely filled in by waste 

 from the ice-tongue to valley margin, and here the typical lobe form was found. 

 One of the best examples is seen at Poquetannock cove, on the east side of the 

 river, where there is a large amount of washed drift, on the eastern margin of 

 which there are a number of well developed lobes which point eastward, as if 

 formed by streams flowing from an ice tongue in the center of the river. 



The ice-contact slope or moraine terrace is the steep slope of these flat-topped 

 deposits which now faces the Thames river, if the above outlined delta hypothesis 

 is to replace the floodplain hypothesis. It would then follow that the washed 

 drift in this valley had been very slightly altered in form since the last retreat of 

 the ice. In all points where man has not materially changed the aspect of these 

 terrace slopes the form seems to the writer to be better explained as an ice-contact 

 slope than in any other way. In a number of places boulders are found on these 

 steep slopes facing the river, the position of which is easy to explain if we con- 

 ceive a contiguous ice-margin from which they might have fallen ; but it is impos- 

 sible to see how they could stand where thej'' do if the edge of this deposit is the 

 result of erosion. 



There are many other interesting features about these Thames River deposits, 

 such as the rock hill at Montville, around which the ice flowed in two streams, 

 forming two sets of terraces, the sandplain at Montville, or the extensive plains at 

 Norwich, which should all be described in making out the history of this region 

 in the way it has been done for Narragansett bay.J The field survey for this work 

 has not been completed yet, so the details of the history of these deposits is not 

 here given. Enough facts have been mentioned to show that these delta- terraces 

 were formed when the ice was present in the drowned valley, and the suggestion 

 is made that the structure of other so-called glacial terraces be examined to see if 

 they were not similarly formed. There are undoubted fluviatile terraces,? and 

 these should be discriminated from such delta- terraces as are here described. 



A most interesting question is the water level shown by these delta deposits. 

 It may be the sealevel, in which case a tilting of the land is shown bj' these Thames 

 River deposits, the greater elevation being inland ; it may be a series of lakes, as 

 has been suggested by Mr Robert Chalmers, || or it may be that there was a block- 

 ing up of the valley at New London by ice or rock waste or both, and that as the 

 ice melted first from the sides of the valley it left water bodies on each side of an 



* Nat. Geog. Mag., vol. iii, 1891, pp. 106-109. 



t W. M. Davis, in Bull. Geol. Soe. Am., vol. i, 18S-, pp. 195-202. F. P. Gulliver, in Chicago Jour, 

 of Geol., vol. i, 1893, pp. 803-812. 

 t J. B. Woodworth, in .\m. Geologist, vol. xviii, 1890, pp. 150-168. 



g See paper by R. E. Dodge, in Proc. Boston Soc. Nat. Hist., vol. xxvi, 1894, pp. 257-273. 

 II Ann. Rep. Geol. and Nat. Hist. Survey of Canada, vol. iv, 1888, p. 01. 



