W J MCGEE — A FOSSIL EARTHQUAKE. 411 



The following paper was then read : 



DISTINCT GLACIAL EPOCHS AND THE CRITEETA FOR THEIR RECOGNITION 



BY R. D. SALISBURY 



During the animated discussion which followed the reading of this 

 paper remarks were made by W J MeGee, C. H. Hitchcock, Warren 

 Upham, Robert Bell, B. K. Emerson and the President. The paper is 

 published in full in The Journal of Geology, volume i, pages 61-84. 



The last paper of the afternoon session was — 



PLEISTOCENE PHENOMENA IN THE REGION SOUTHEAST AND EAST OF LAKE 



ATHABASKA, CANA I >A 



BY .1. B. TYRRELL 



Remarks were made by C. H. Hitchcock, Warren Upham and Robert 

 Bell. 



Announcement of the lecture in the evening was given, and the Society 

 adjourned. 



Evening Session of Wednesday, December 28 



The Society was called to order at 8 o'clock in the Normal School 

 auditorium. A lecture was given upon the following subject : 



A FOSSIL EARTHQUAKE 

 BY W I MCGEE 



lAbslract] 



With a single exception, the traveler by steam-packet on the lower Mississippi 

 funis the river flanked by alluvial hanks so low that during great freshets they 

 are overflowed all the way from Cairo to the Gulf, save where protected by natural 

 or artificial levees. The exceptional locality comprises nearly all of Lake county, 

 Tennessee, and a considerable area in Missouri, on the opposite side of the river. 

 This area, which is some 20 miles in mean diameter, bulges upward in the form 

 of a low dome, 20 or 25 feet above the general level of the alluvial plain. East of 

 it lies Reelfoot lake ; west of it the "Sunk country" of southeastern Missouri and 

 northeastern Arkansas, and through its erest the Mississippi has cut a meandering 

 trough. When the surface of the dome is examined it is found to he scored by 

 broad trenches like the channels of waterways; moreover, these trenches are 

 Hanked by natural levees so characteristic of the Mississippi flood-plains that they 

 are at once recognized as bayous from which the waters have been removed. The 

 structure of the dome is revealed in the channel of the Mississippi. Tt is com posed 

 of a sheet of alluvium, ll) to .'!() feet thick, identical in character with the modem 



L XI -Bui. i.. (ion,. Soc. Am., Vol. I, 1892. 



