94 T. C. Ghamhi rlinr—Oorrdatum of Terminal Moraii 



River, the special interest of this discussion attaching 

 last. 



2. The moraine does 

 area, but is distant fr 



3. The moraine marks a second glacial advance separated fro'ui 

 the former by a considerable interval of time. From the consider- 

 ation of several distinct lines of evidence, the impression has 

 been gained that the interval which separated the earlier from 

 the later glaciatiou. was equal to, or greater than, that which 



I since the latter. But the correctness or otherwise 

 of this is unimportant to our present purpose. 



Somewhat later a similar attempt was made by eastern geol- 

 ogists to trace out an analogous moraine in the coast region. 

 The result of their investigations was the determination of a 

 massive morainic belt traversing northern New Jersey, the 

 entire extent of Long Island, and the smaller islands king to 

 the eastward, sti ._ tin Atlantic on the peninsula "I Cape 

 Cod. Concerning this it is likewise essential to note two char- 

 acteristics and a negation. 



1. Unlike the western moraine, it is not disposed in eon.*i>icu- 

 ous loops, as now delineated. This is the more to be remarked, 

 since the surface inequalities of the region lying north of it are 

 greater than those of the interior. 



2. This moraine marks the southern limit of the drift-sheet. 



3. It has not yet been determined whether this moraine rep- 

 resents the limit of the earlier or later glacial advance. 



Notwithstanding their diilereticos, the ehai.-icteristics of the 

 eastern and western moraines are so strikingly similar, that 

 their tentative correlation as portions of a single moraine pre- 

 sented itself on the first appearance of Professor Cooks results, 

 and was given expression to in the paper above cited. The 

 correct correlation of these moraines and the decisive deter- 

 mination as to whether the coast member belongs to the earlier 

 or later period of glaeiation. are manifestly qne-tions of great 

 interest, and the purpose of this paper is to make a prelimb 

 nary contribution toward their solution. The hypothesis of 

 their unity is somewhat strengthened by the fact that thus far 

 no similar moraine has been traced along the margin of the 

 drift in the interior. It may be, however, unsafe to assume 

 the absence of such moraim-' until the region shall have been 

 critically examined with especial reference to this question. 



During the past year Professors Lewis and Wright, of the 

 P< tsyk mi Surv< have h n ng igt l in tracing a margi ia 

 moraine from the western terminus of the New Jersey range. 

 across Pennsylvania. Their re- Mished, and 



will be awaited with interest. 



