TTT'DSOX IJlVKi; BEDS KKAll Air. ANY 11 



inarii:in of the area ot" no vertical stress, or for brevit}' the line of no vertical stress, 

 along which and without which there is no vertical component of the stress due to 

 load, hut about which act the moments of the load within the overloaded area. 

 The converjience of vertical planes downward imposes a restraint upon the de- 

 pression of a crustal block within vertical walls, and tends to form new rupture 

 planes if the thickness of the crustal block be small in comparison with its area. 



The principles discussed are applied to exi)lain the observed faults witliin the 

 valley of the Pomperang river, Connecticut. 



The following paper was read by the"author, who was introduced by 

 J. M. Clarke : 



HUDSON EIVER BEDS NEAR ALBANY AND THEIR TAXONOMIC EQUIVALENTS 



BY RUDOLF RUEDEMANN 



\^Ahstract] 



This paper is the first installment of an investigation of the belt of so-called Hud- 

 son River beds, extending on both sides of the Hudson river in eastern New York. 

 It gives tlie results obtained between the mouths of the Mohawk river and Coey- 

 mans Kill. 



The uniform mass of shales and sandstones with conformable easterly dip, which 

 hitherto, as "Hudson River beds," has been considered as representing the time 

 interval between the Utica and Oneida ages, can, by means of the entombed 

 faunas, be separated into Lower, Middle, and probably Upper Trenton beds, Utica 

 shale, and Lorraine beds. All of these stages are represented by belts of similar 

 rocks, extending from west-northeast to south-southeast with the general strike 

 of the rocks. The whole series is overturned, being the underturned wing of an 

 overturned fold of A ppalachian type. 



Remarks were made by J. M. Clarke. 



The three following papers were read by title : 



FAUNA OF THE ARENACEOUS LOWER DEVONIC OF AROOSTOOK COUNTY, MAINE 



BY JOHN M. CLARKE 



GIANTS' KETTLES ERODED BY MOULIN TORRENTS 



BY W^ARREN UPHAM 



This paper is printed in full in this volum-e. 



PLEISTOCENE ICE AND RIVER EROSION IN THE SAINT CROIX VALLEY OF 



MINNESOTA AND WISCONSIN 



BY WARREN UPHAM 



This paper is printed in full in this volume. 



After announcement of excursions under the guidance of Professor 

 J. F. Kemp, the Society adjourned. 



