GEOLOGICAL PAPERS 115 



7. Strong Shock : Overthrow of movable objects, fall of plas- 

 ter, ringing of church bells : general panic without damage to 

 buildings. 



8. \'er}- Strong Shock: Fall of chimneys, cracks in the walls 

 of buildings. 



9. Extremely Strong Shock: Partial or total destruction of 

 some buildings. 



10. Shock ojt Extreme Intensity: Great disaster, ruins, dis- 

 turbance of the strata, fissures in the ground, rock- falls from 

 mountains. 



The original data, newspaper clippings, letters, etc.. upon which 

 this paper is based have been left in the Denkmann ^Memorial 

 Library of Augustana College, where they may be obtained by 

 application to the Librarian. 



NOTES OX SAXGAMOX COUXTY LIMESTOXES. 

 A. R. Crook. 



The following information was furnished by diamond drill 

 cores from a drilling made some years ago at Divernon. sent 

 two years ago to the State Museum and just made accessible for 

 study and exhibition. 



For stratigraphic investigation it is true that drill cores are 

 small, are deficient in weathered fossils, and lack the prominent 

 features of outcropping ledges. But they have the advantage of 

 presenting for examination every foot of strata underlying a 

 given point and showing the exact location of the various strata 

 in relation to each other, ^^'hile clays and soft shales are washed 

 out by the water used in keeping the drill hole clean, their thick- 

 ness is recorded and samples show their character. 



Divernon is seventeen miles south of Springfield and about two 

 miles from the south line of Sangamon County. The boring 

 began at about 600 feet above sea level and ended at a depth 

 of 604 feet. First it went through 9 feet of loess. 15 feet of 

 'Tllinoian" till and 16 feet of "Kansan" till, and at a depth of 

 40 feet reached the rock, a limestone. This limestone and all the 

 subsequent strata encountered constitute the upper half of the 



The word? in italics have been added by the author. 



