M''GKE NOTES ON THE GEOLOGY OF MACON CO., MO. 333 



the Coal Measures far above the Macon county series,* together 

 with its associates, occur in nearly equal abundance in the two 

 limestones below tlie Carbon coal, and more rarely in all the lime- 

 stones of the series. Fortunately the occasion for examining the 

 taxonomic relations of the naturally exposed strata does not exist, 

 since they have been acceptably referred by the widely-known 

 othcial geologists of the State, Professors Swallow and Broad- 

 head to the Lower Coal Measures, as defined by the formerf and 

 applied in Macon cou:ity by the latter. J The ^'Ferruginous Sand- 

 stone" of these authors was not recognized either in outcrops or 

 in the boring records ; and the Coal Measures may be regarded 

 as terminating above the 35-foot limestone forming Nos. 18 and 

 19 of the record. 



The data atlbrded by the borings are too meagre to indicate 

 decisively the relations of the several strata penetrated ; but, on 

 comparing the materials and thicknesses of the groups into which 

 they fall with the general sections developed by the State surveys 

 of Missouri, Illinois, and Iowa (a sort of composite of which was 

 prepared for use in prognosticating the results of the boring), it 

 becomes apparent that the first group, with perhaps some of the 

 subjacent shales, simulates the St. Louis ; that the combined 

 second and third, with perhaps part of the fourth, correspond 

 closely with the Keokuk ; that the fifth and the remaining part 

 of the fourth occupy the place and exhibit the characters of the 

 Burlington ; that the sixth is allied to the Kinderhook ; that the 

 seventh agrees fairly well with the Niagara ; and that the eighth 

 closely approaches the Hudson River, to which the ninth may 

 also belong. Accordingly, the various strata exposed naturally 

 and penetrated by the drill in Macon county may be tentatively 

 classified as in the following table, in which there is also intro- 

 duced, cliiefly to indicate the possible extent of the personal equa- 

 tion in influencing the classification, the section predicted when 

 the drill was in the 35-foot limestone. 



* ist & 3d Rep. Gen'l Survey Mo., Swallow, 1855, pt. ii. 201, pi. C fig. 10. 

 \ Op. cii., S9-91. 



t Rep. Geol. Survey of Mo., 1855-71, by Broadhead, Meek, and Shumard, 1S73, 74-92; 

 Atlas ace. Rep. on Iron Ores and Coal Fields, 1873, pi. v. 



