532 



SCIENCE. 



[N. S. Vol. XIX. No. 483. 



geologic conditions free from complicated 

 structure and possessing fairly well-marked 

 topographic forms from which its physio- 

 graphic history may be interpreted. The 

 present paper is the result of an ett'ort to 

 make a systematic study of the ph.ysio- 

 graphic features of this part of the state, 

 and it is based largely upon a careful study 

 of the contoured topographic maps that 

 have been assembled and reproduced here 

 for the first time. The author has ap- 

 proached the question free from any bias 

 regarding the ability of glaciers to accom- 

 plish extensive erosion, and has dealt with 

 the problem entirely from the physio- 

 graphic standpoint ; an effort was made 

 first to account for the present topography 

 largely through the simple process of sub- 

 aerial erosion, but this failed to explain the 

 peculiar features of the region. The con- 

 clusion arrived at is that ice was the prin- 

 cipal agent in not only giving the finishing 

 touches to the present topography, but in 

 the extensive erosion which has reduced 

 this portion of the state from an altitude 

 of approximately 2,000 feet to that of 800 

 or 1,000 feet above sea level, and that has 

 produced the great topographic embayment 

 of the Finger Lake region. 



Evidences of Slight Glacial Erosion in 

 Western Neiv York: H. L. Fairchild. 



Wan/ing of the Glaciers of the Alps: H. L. 



Fairchild. 



Lantern views from photographs taken 

 during the past summer illustrating the 

 decrease of the Alpine glaciers within re- 

 cent years. 



The Carhoniferous of the Appalachian 

 Basin; Part II., the PottsviUe: J. J. 

 Stevenson. (Read by title.) 



Notes on the Deposition of the Appalachian 



PottsviUe: David White. 



General view of the thickness and pres- 

 ent distribution of the main divisions of 



the PottsviUe sediments in the Appalachian 

 trough. Extent and duration of the basal 

 uniformity as indicated by fossil plants. 

 Suggestions as to conditions of deposition 

 of the several divisions. 



The Benton Formation in Eastern Soutli 

 Dakota: J. E. Todd. 



Further -Studies of Ozark Stratigraphy: 



C. F. Marbut. 



During the past summer the reconnois- 

 sanee mapping of the formations of the 

 Ozark Series was extended over the south- 

 central counties of the state. The paper 

 will describe the character and distribution 

 of the various formations, and discuss 

 briefly the evidence on which the correla- 

 tion is based. 



The Iroquois Beach in Ontario: A. P. 



Coleman. 



The detailed mapping of the Ii'oquois 

 Beach in Ontario was begun in 1898 and 

 practically completed in 1902, but publica- 

 tion was delayed in hopes of extending the 

 work northeast from Ilavelock, the last 

 point at which the beach could be found. 

 As it can be traced no farther, it is prob- 

 able that the shore to the east and north 

 consisted of ice. The highest point reached 

 is 498 feet above Ontario or 744 feet above 

 the sea. Northeast of Colborn it is split 

 up into several beaches, in one ease the 

 highest being 80 feet above the lowest ; but 

 southwest to Hamilton the beach is prac- 

 tically a unit, and the same is true on the 

 south shore to Niagara River. There is 

 evidence of the splitting up of the water 

 levels at Toronto and Hamilton in the 

 form of old surfaces of erosion, soils with 

 trees, and remains of mammoth, etc., at 

 levels from 30 to 80 feet below the gravel 

 bars representing the latest Iroquois lake 

 levels. It is believed that the evidence ob- 

 tained proves that the Iroquois water was 

 a lake with an ice barrier to the northeast, 

 and not an arm of the sea. 



