288 D. WHITE — AGE OF LOWER COALS OF HENRY CO., MISSOURI. 



and, since the Lower Productive Coal Measures of the more eastern states 

 is, paleobotanically, by far the best known portion of the sections, the 

 material in hand is better adapted to immediate correlative comparisons 

 with the Coal Measures floras in the eastern basins than is that from a 

 higher stage. 



Local Stratigraphy of the Coals. 



source and nature of data employed. 



In Henry county, Missouri, the Lower Coal Measures is said to rest 

 on a deeply eroded Mississippian (Eocarboniferous) floor strewn with 

 chert and other debris from the Saint Louis limestone or other members 

 of that series. The lowest coal-bearing shales lie in erosion pools, estua- 

 ries, or ponds, and are disposed as filling or levelling material along the 

 shores of the encroaching Carboniferous sea. The series is according] y 

 in general thickest over the lower portions of the floor, thinning out 

 against the contemporaneous barriers and ridges. The greater part of 

 the botanical material in hand is obtained at several localities in the 

 region of Clinton, from what is described in the numerous published 

 sections* of this series as the "Jordan coal." The remainder comes 

 from the second higher seam, about 45 feet from the Jordan coal, on the 

 Grand river, near Gilkersons ford. Both of these beds are included in 

 the Lower Coal Measures of the earlier state reports or in the lower part 

 of the " Des Moines," as proposed by Keyes.f Generally a thin and very 

 irregular "ferruginous sandstone," the "Spring River sandstone ' : of 

 Jenney, intervenes between the coal-bearing shales and the Eocarbonif- 

 erous bottom. J In this region the plant-bearing horizons nowhere 

 exceed an interval of 100 feet above the sandstone, while at some points 

 they come in contact with its uneven surface. This sandstone, which is 

 regarded as " Millstone grit " by the Missouri geologists, and whose more 

 eastern representative was included in the Chester by the geologists of 

 Illinois, appears rarely to be entirely absent locally, in which case the 

 lower coals practically abut against the old shore. 



RELATION OF AGE OF THE COALS TO EARLY MESOCARBONIFEROUS EPEIRO- 



GENIC MOVEMENTS IN MISSOURI. 



The trans-Mississippi epeirogenic movements of the Carboniferous 



* Broadhead : Rep. Geol. Survey of Missouri, 1872, part 2, pp. 6, 7, 16, 82, 88 ; Rep. Geol. Survey 

 of Missouri, vol. viii, 1895, pp. 360-369. Winslow : Preliminary Report on the Coal Deposits of 

 Missouri, 1891, p. 139, fig. 97; p. 141. fig. 99 ; p. 140, fig. 98. 



f American Geologist, vol. xviii, 1896, p. 23 ; Report Geol. Surve3' of Iowa, vol. i, 1893, p. 85. 



I The age of this sandstone, which, it Would seem, may possibly in part represent the work of 

 the encroaching sea in assorting the subaerial Mississippian debris, has not, I believe, been deter- 

 mined from paleontologic evidence. 



