Mat 17, 1907] 



SCIENCE 



773 



systems are of early Quaternary origin. 

 That prior to the first ice invasion of the 

 Quaternary the whole upper Mississippi 

 drainage was to the north into the Hudson 

 Bay. The movement of the ice into this 

 basin advanced upon a rising plane. The 

 margin of the ice was generally uniform 

 and attenuated. The impounding of the 

 drainage waters resulted in extensive 

 frontal lakes. Sluggish action of the ice 

 and poorly developed moraines, extensive 

 sheets of extra morainic drift, slow move- 

 ment of the waters from the ice front with 

 deposition of loess and with general aggra- 

 dation along the stream courses, the modi- 

 fication of preglacial topography and pro- 

 found changes in drainage were some of 

 the resultants. A new outlet to the south 

 along the line of the present Mississippi 

 over a low col between the southern end 

 of the Appalachians and the Ozarks, was 

 established and the general plan of the 

 present drainage lines of the Mississippi 

 basin developed. The later ice invasion of 

 the Quaternary into the basin followed the 

 establishment of gradients and developed 

 the general lobate form of the margin 

 characteristic of these invasions and pro- 

 duced only local and minor frontal lake 

 phenomena south of the continental divide 

 which was later discovered by the reces- 

 sion of the ice. The development of strong 

 lobate moraines, the distribution of but a 

 small amount of extra morainic drift, and 

 the vigorous action of the streams dis- 

 charging from the later ice fronts, were 

 characteristic phenomena. The paper re- 

 cited some of the evidence in support of 

 the hypothesis and asked for more careful 

 observation of the phenomena upon which 

 data must be collected to prove or disprove 

 the hypothesis. 



Professor Tight 's paper was discussed 

 by Messrs. Leverett and Carney. 



Glacial Flowage over New England: J. B. 

 WooDwORTH. Read by title. 



Quaternary Changes of Level in New Eng- 

 land: Fredekick G. Clapp. No abstract 

 received. 



Mr. Clapp 's paper was discussed by Pro- 

 fessors Leverett, Hitchcock, Alden and Ami. 



Glacial Lake Memphremagog: C. H. 



Hitchcock. 



The existence of this lake was pointed 

 out at the meeting of the Geological So- 

 ciety of America in 1894 (Bull. Geol. 8oc. 

 Am., Vol. 6). Eecent studies show that it 

 was tributary to Glacial Lake Champlain 

 by way of both the La Moille and Winoo- 

 ski valleys. When the ice filled the Cham- 

 plain valley to the depth of a thousand feet, 

 the impounded water upon the east side 

 could have reached the Connecticut valley 

 by way of White River. 



Professor Hitchcock's paper was dis- 

 cussed by Professors G. F. Wright and 

 Richardson. 



Pre-Wisconsin Drift in the Finger Lake 



Region of New York: Frank Carney. 



No abstract received. (Introduced by 



H. L.Fairchild.) 



Mr. Carney's paper was discussed by 

 Professors Tarr, Clapp and Leverett. 



Wave-cut Terraces in Eeuka Yalley Older 

 than the Becession Stage of Wisconsin 

 Ice: Frank Carney. No abstract re- 

 ceived. (Introduced by H. L. Fairchild.) 

 Mr. Carney's paper was discussed by 



Professor Clapp. 



Deposits of Glacial Age in the Non-glaci- 

 ated regions of Central Asia: Ellsworth 

 Huntington. 



Different rates of weathering, and con- 

 sequently of erosion and deposition, during 

 glacial as opposed to inter-glacial epochs 

 in arid regions appear to cause the alter- 

 nate deposition and erosion of gravel beds 



