54 The Badland Formations of the Black Hills Region 



shores and about the mouths of tributary streams, and that the 

 wide distribution of the animals now found as fossils was ac- 

 complished by the drifting about in the lake of the decaying^ 

 bodies washed down by the inflowing streams. The fossils ob- 

 tained by the earlier students of the region showed a general 

 lack of an aquatic fauna. As a result the idea developed that the 

 waters of this great lake although receiving the drifting bodies 

 of land animals were themselves of such a saline or alkaline 

 nature that they were incapable of supporting life. It has more re- 

 cently been shown that the waters were not only not saline, but 

 that they were eminently fitted for the support of aquatic life 

 and in fact in some localities did support such life, both plant and 

 animal in great abundance. 



The objections to the earlier views have been fully stated 

 by Mr. W. B. Matthew, Prof. W. M. Davis, Mr. J. B. Hatcher, 

 and others and are in brief as follows :* 



Stratigraphic Evidence . First, the formations as now geog- 

 raphically determined if dqiosited in a lake would have de- 

 manded a body of water comparable in area to that of a great 

 sea, and, during the long period required for the deposition of 

 the sediments, should have developed important shore terraces. 

 Such terraces, although diligently searched for, have not been 

 observed. 



Second, the lake must have been caused by a deformation 

 of the earth's surface sufficiently rapid in its development to 

 counteract the opposing channel cutting tendencies of the 

 streams and of sufficient magnitude to overcome whatever 

 aggrading influence the streams may have developed. There is 

 no known evidence of any such basin-forming structure, the 

 sediments lying on a surface which slopes gently and uniformly 

 to the east. 



Third, thin beds of sandstone and conglomerate occur in 

 many places with the clays. These not infrequently show 

 marked cross bedding and other swift current characters, and 



*1896. Gilbert, G. K., U. S. Geol. Surv., 17th Ann. pt. 2, pp. 

 557-601. 



189 7. Haworth, E., Kan. Univ. Geol. Surv., Vol. 2. 



1899. Matthew, W. D., Am. Nlat., Vol. 33, pp. 403-408. 



1900. Davis, W. M., Proc. Am. Mus. Acad. Arts Sci., Vol. 35,. 

 pp. 345-373. 



19 01. Matthew, W. D., Am. Mus. Nat. Hist., Mem. Vol. 1, pp. 

 355-447. 



1901. Johnson, W. D., U. S. G. S., 21st Ann. pt. 4, p-p. 609-741. 



1902. Hatcher, J. B., Proc. Am. Phil. Soc, Vol. 41, pp. 113-131. 

 1909. Osborn, H. F., U. S. G. S., Bull. 361. 



