Tarr — Origin of the Chert in the Burlington Limestone. 427 



Analyses of Spring Waters from the Pennsylvanian and 

 Mississippian formations near Columbia, Missouri. 





A 



B 



c 



D 



€1 



13-52 





26-88 



74-31 



^^4 



2122-97 



1563-42 



3-23 



.. 



co: 



30-47 



237-20 



310-13 



303-89 



Na 



8-90 



44-14 



18-31 



47-51 



Ca 



318-56 



535-12 



111-78 



89-20 



Mg 



53-85 



106-20 



6-83 



10-22 



Fe 



246-65 



29-21 





._ 



AIA 



269-26 



13-47 



5-32 



31-25 



SiO^ 



43-31 



24-96 



12-08 



31-41 



Paris per million 3107'49 



2553-72 



494-56 



587-79 



A. Sulphate water from Bratton Spring in Pennsylvanian forma- 



tion near Stephens station, northeast of Columbia, Mo. 

 Analysis by Paul Schweitzer. 



B. Sulphate water from spring in Pennsylvanian formation on 



University campus, Columbia, Mo. Anal3'sis by Paul 

 Schweitzer. 



C. Carbonate water from Rollins Spring in Burlington limestone 



on University farm, one mile from Columbia, Mo. Analy- 

 sis by Paul Schweitzer. 



D. Carbonate water from spring in Burlington limestone on 



John W. Harris' Farm, eight miles south of Columbia, Mo. 



Analysis bj Paul Schweitzer. 

 All analyses from vol. 3, Mo. Geol. Surv., 1892. 

 They have been recalculated to parts per million. 



they have been working on essentially the same sorts of rocks 

 since Mississippian times. A similar conclusion was reached 

 as to the time of the development of the chert in the con- 

 glomerates and cave deposits of the Cambrian and Ordovician 

 formations. The length of time since then is certainly great 

 enough for the ground waters to have changed the chert if it 

 were possible for them to do so. Therefore, if the waters 

 were able to dissolve the silica in the earlier periods, why not 

 during the later? It would seem that the evidence as to the 

 age of the chert in the Mississippian is against the probability 

 of the aggregation of the silica being due to ground waters. 



III. Origin of the Chert. 

 A. outline of theory. 



The writer's study of the chert in the Burlington limestone 

 has led him to the following view CDucerning its origin. The 

 silica is believed to have been derived from the land by chemi- 



