286 KANSAS UNIVERSITY QUARTERLY. 



Falls limestone has produced salt water, the argument is as applicable 

 to any one as to another. 



GENERAL CONDITION OF DEPOSITION. 



From the foregoing arguments and conclusions it is evident that 

 throughout the Coal Measure time the conditions over that part of the 

 globe now occupied by the ('oal Measure formations of Kansas were 

 exceedingly variable, yet changed in a cycle-like manner, so that any 

 one condition had periods of recurrence, thereby duplicating results 

 quite a number of times. It has been pointed out that no less than 

 25 different limestone forming periods occurred, and also a similar 

 number of shale and sandstone forming periods. The geographic 

 and geologic positions of the different kinds of rocks produced also 

 have been given as covering a great range. Thus the Burlingame coal 

 is more than 100 miles geographically and nearly 2000 feet geologically 

 from the coals in the Cherokee shales, and yet practically the same 

 set of conditions obtained during the formation of both. Attention 

 has also been called to the general thickening of so many of the 

 formations to the southwest, as represented by the Pleasanton shales, 

 which more than double their thickness, the Independence limestone, 

 which quadruples its thickness, and the lola limestone which increases 

 from 40 to more than 100 feet. That the sandstone formations also 

 thicken in a similar manner has been illustrated by the Lane shales 

 which carry the heavy sandstone beds in the vicinity of Burlington- 

 But the Lawrence shales have been pointed out as reversing this 

 general order, for they thicken from near 100 feet at the Neosho 

 river to 300 at Lawrence. 



Now an interesting question arises as to what conditions must have 

 obtained in order to produce so widely diversified results over so 

 great an area. The frequent recurrence of sandstone with ripple 

 marks and rain drop markings throughout the whole area and vertical 

 distance can only be accounted for by admitting the frequent exist- 

 ence of shallow areas or lagoons under which such sandstones were 

 deposited. The drill records of the many dozens of deep wells 

 recently sunk only emphasize tliis statement; for not a single well has 

 been drilled which did not pass through many different sandstone 

 beds widely separated, often by heavy sandstone systems. It would 

 seem that we must have a great period of intermittent subsidences, 

 with the greatest variation in elevation taking place to the south 

 and west, while nearer the borders of the Mississippian the ver- 

 tical oscillations were much milder. From paleontologic evidence 

 it would seem that the great limestone forming periods usually 

 were abruptly closed; for as Bennett has pointed out the great 



