Springs: The Influence of Stratigraphy. — Hopkins. 365 
having observed anything in this coal bed or in the strata im- 
mediately below and above it that could be regarded as evi- 
dence against the idea just stated. The absence of StigmaricB, 
of erect tree stumps with root processes attached, and of ir- 
regularities of stratification ; and the presence of numerous 
remains of a rich aquatic fauna in places and at more than 
one horizon in the seam;* with, here and there, areas of lime- 
stone where the "draw-slate" occurs (in which "slate" I have 
seen a traveled boulder of hard yellow limestone) — all these 
facts can only be explained by an aqueous origin for this 
coal. 
SPRINGS: THE INFLUENCE OF STRATIGRAPHY 
ON THEIR EMERGENCE, AS ILLUSTRATED IN 
THE OZARK UPLIFT. 
By T. C. Hopkins, University of Chicago, III. 
(Plate XI.) 
There is probably nowhere in the United States a better op- 
portunity for observing the influence of stratigraphy on the 
emergence of springs than in the Paleozoic area of northern 
Arkansas and southwestern Missouri, an area known as the 
Ozark uplift. 
In most mountainous areas the strata are generally much 
flexed and faulted, so that the emergence of springs is gov- 
erned largely by the position of the strata and is not so di- 
rectly dependent upon the lithologic character of the different 
layers as is the case when the strata are horizontal or nearly 
so, with only few faults. Over a large part of the Ozark up- 
lift the strata are very nearly horizontal and are deeply 
eroded by White river and its numerous ramifying tributa- 
ries, thus exposing a great vertical thickness of the differenl 
layers, so that we have a nearly ideal condition for observing 
the direct influence of the different beds on the emergence of 
the springs. It is true that the Grand Canyon area <>f the 
west has deeper erosion, but the lack of rain makes it spring- 
less. 
The strata in the Arkansas-Missouri area consist of ditl'er- 
*See Pa. Geol. Surv. Final Report, vol. iii (to be published, 1894). 
