Apeil 16, 1909] 



SCIENCE- 



627 



Then was presented a paper by Professor Al- 

 brecht Penck, of Berlin, who had been invited by 

 the council to participate in the meeting. Pro- 

 fessor Penck chose as his theme " Interglacial 

 Epochs." 



At the close of this paper the special section 

 on correlation withdrew for the continuation of 

 its sessions, and the general section, with Presi- 

 dent Calvin in the chair, proceeded with the main 

 program. 



The following two papers were read: 



Glacial Waters West and South of the Adiron- 



daeks: H. L. Faikchild, Rochester, N. Y. 



As the lobes of the ice sheet melted away south 

 of the Adirondacks, high-level waters were held 

 in the Schoharie and Mohawk valleys, into which 

 was poured the land and glacial drainage of the 

 time, with consequent elevated deltas. The Scho- 

 harie Lake had outlets to the Hudson and the 

 Delaware; and subsequently the Mohawk waters 

 overflowed southwestward to the Susquehanna, 

 but finally to the Hudson. 



The earliest outlet of the Mohawk Valley waters 

 seems to have been by the col at the head of the 

 Otsego-Susquehanna valley, with elevation some- 

 what under 1,400 feet. A lower escape was found 

 by the Unadilla Valley, at about 1,220 feet, and 

 possibly by the Chenango Valley at 1,150 feet. 

 Later the outflow was eastward to the Hudson 

 by Delanson and Altamont and past the face of 

 the Helderberg scarp, at 840 feet as the lowest. 

 The latest flow of the ice-impounded Mohawk 

 waters was south of Amsterdam and past the face 

 of the scarp at Rotterdam. 



The copious drainage of the western slopes of 

 the Adirondacks poured into a lake held in the 

 valley of Black River, with the production of a 

 remarkable expanse of sand plains. In the various 

 features and relations which characterize a glacial 

 lake the Black Lake is probably the finest example 

 of a glacial lake in the state (though not nearly 

 so remarkable in complexity of drainage and his- 

 tory as the Genesee waters ) . The earliest outflow 

 of the differentiated waters of the Black Valley 

 was southward past Remsen into the Mohawk 

 Lake, with delta built at Trenton and Trenton 

 Falls. The second escape was southwestward, at 

 Eoonville, into the inferior Mohawk Lake, with 

 delta north of Rome. The third stage had west- 

 ward outflow, curving around the high ground 

 between the Black Valley and the Ontario basin, 

 at Copenhagen and Champion, the flood pouring 

 into Lake Iroquois at Adams. 



Correlation of the Hudsonian and the Ontarian 



Glacier Lobes: H. L. Faiechild, Rochester, 



N. Y. 



In the waning of the Labradorian ice body the 

 Adirondack massif became uncovered, at first as 

 an island, with probable westward flow of the ice 

 through the Mohawk depression. Later the gla- 

 cial flow was divided into a Champlain-Hudson 

 lobe and a St. Lawrence-Ontario lobe. For a long 

 time the Hudsonian lobe pushed an ice tongue 

 westward into the lower Mohawk valley, while 

 tlie Ontarian lobe sent one eastward into the upper 

 Mohawk valley. Imprisoned between the two op- 

 posing ice fronts the glacial waters stood at high 

 levels in the Mohawk and Schoharie valleys. As 

 the waning ice margins released successively lower 

 passes to southern drainage the waters fell ac- 

 cordingly. 



The delta sand plains on the flanks of the Adi- 

 rondacks and in the upper Mohawk valley, with 

 their various declining altitudes, show the succes- 

 sive levels of the waters; and these levels were 

 determined by the positions of the ice margins 

 with reference to a few critical cols or passes on 

 the divide. 



These two papers were discussed by Professors 

 A. P. Brigham, H. L. Fairohild and A. W. Grabau. 



The next paper was read by title. It was: 



Pleistocene Features in Northern New York: H. 

 L. Faiechiu), Rochester, N. Y. 

 Then the society listened to: 



Pleistocene Geology of the Southwestern Slope of 



the Adirondacks: W. J. Miller, Clinton, N. Y. 



(Introduced by W. B. Clark.) 



The area discussed in the paper is about sixty 

 miles long and fifteen miles wide and extends 

 from Lowville to Dolgeville, N. Y. Certain evi- 

 dence clearly indicates an early southeasterly 

 movement of the ice, while other evidence shows 

 0. later, more general southwesterly direction of 

 flows. Tlie Black River Valley has been consid- 

 erably deepened and modified by ice erosion. A 

 distinct kame-morainic belt has been traced the 

 whole length of the area. Associated with this 

 moraine are so-called " sand plains," whose origin 

 is discussed. Extinct glacial lakes are shown by 

 the presence of considerable areas of stratified 

 clay. The pre- and post-glacial drainage of the 

 region and the origin of the " gulfs " were dis- 

 cussed. 



The paper was discussed by Professor G. K. 

 Gilbert. 



Then was read: 



