4:66 Scientific Intelligence. 



short distances in the texture and composition of the limestones. 

 Further, " local lenses of sandstone have been observed at some 

 localities." In the Niagaran formation of northern Indiana, there 

 is "a notable exception to the nearly horizontal and undisturbed 

 condition which generally characterizes most of the other forma- 

 tions of Indiana." In the upper Wabash valley, " the strata are 

 frequently found to be highly inclined." The dips vary from 5° 

 to 80°. 



"The general structure of the Niagara beds of northern Indiana 

 is that of a broad arch with gently sloping sides trending north- 

 west and southeast. It represents a northwestern extension of 

 the Cincinnati geanticline. Its axis, approximately located, enters 

 the state near Richmond, and passes northwesterly in the vicinity 

 of Muncie, Marion and Peru, and continues north of the Wabash 

 through Cass, White, Jasper and Newton counties into Illinois. 

 On the two sides of this line of maximum elevation of the Niagara 

 the Devonian and Carboniferous rocks dip in opposite directions ; 

 in Michigan and Ohio, toward the north and northeast ; in Indiana, 

 toward the southwest or south " (p. 409). "The arch described 

 above is not the * Wabash Arch' of Gorby, which apparently was 

 supposed by its author to follow the Wabash Valley in eastern 

 Indiana " (p. 409). " The dips seem everywhere to be quaquaversal, 

 and it is believed that all of the tilted Niagara beds of northern 

 Indiana represent small domes similar to those at Huntington and 

 Wabash " (p. 411). "There is at present no positive evidence as 

 to the nature of the forces which produced the domes. It seems 

 probable, however, that they may be analogous in origin to the 

 'mud lumps' at the mouth of the Mississippi" as recently 

 described by Harris. 



"Whatever the causes may have been which produced the 

 domes, there is clear evidence that they were developed about the 

 close of the Niagara period. Many of them were elevated above 

 the Paleozoic sea, while others probably did not reach its surface. 

 Some of the domes remained above sea level during a consider- 

 able portion of the Devonian age, and there is some evidence that 

 others continued as islands to the end of Devonian time." 



"The occurrence of outliers of Pottsville conglomerate in the 

 center of the Niagara area of northwestern Indiana near Reming- 

 ton and Jasper indicate that a subsidence occurred alter the for- 

 mation of the Niagara domes which submerged all or nearly all of 

 the Niagara area of that region beneath the Carboniferous sea. 

 The development of the present Niagara arch in northwestern 

 Indiana was, therefore, of much later date and independent of the 

 formation of the Niagara domes. While the domes date back to 

 the end of the Niagara, the Niagara arch is of Carboniferous or 

 post-Carboniferous age." 



" The evidence at hand points to a general elevation of the sea 

 bottoms at the close of the Niagara [Guelph] in the area around 

 the northern end of the Cincinnati geanticline." 



" A study of the faunas of the region has shown the presence in 



