Kindle — Niagara Domes of Northern Indiana. 459 



Art. XLYI. — The Niagara Domes of Northern Indiana; by 

 Edward M. Kindle. 



The earlier workers on the geology of Indiana generally 

 believed the geological structure of the State to be much sim- 

 pler than recent investigations have shown it to be. Their 

 firmly-rooted belief in the uniformity of the geological struc- 

 ture of Indiana prevented many of them from even enter- 

 taining any explanation of the Niagara dips which would 

 include deformation. Prof. John Collett, for many years 

 State Geologist, says in describing Niagara beds which show 

 dips : . . . " the uniform undisturbed condition of the strata 

 of this and adjoining states will not allow the presumption of 

 upheaval and such dislocation of strata as would account for 

 these phenomena."* Starting with the assumption of the 

 " undisturbed condition " of the strata, it is not surprising that 

 Collett was compelled to confess, in describing a locality 

 exhibiting tilted beds, that, " This quarry is a mystery."f 



It will be the purpose of the following pages to show that 

 we have in the Niagara beds of northern Indiana a notable 

 exception to the nearly horizontal and undisturbed condition 

 which generally characterizes most of the other formations in 

 Indiana. A number of theories concerning the structure of 

 the Niagara area and the dips have been advanced, and the 

 more important ones will be briefly reviewed. 



Owen. — Richard Owen first directed attention to the tilted 

 Niagara rocks of northern Indiana. Forty years ago Owen 

 wrote that he had found near Delphi, "A local dip to the 

 southeast amounting to 40°."^: He mentioned also the sharp 

 dips at Wabash and Huntington. 



Cox. — Ten years later E. T. Cox, then State Geologist, gave 

 a brief description of these localities, but ascribed the inclined 

 beds to false bedding. § 



Oblique or false bedding on a large scale is an unusual 

 phenomenon in limestones. The seas in which they are 

 deposited are seldom sufficiently shallow to permit the action 

 of currents strong enough to produce oblique bedding. As a 

 possible explanation of the dips, however, the hypothesis of 

 oblique bedding proposed by Cox deserves an examination. 

 The history of the discussions concerning the LeClaire lime- 

 stone of Iowa illustrates the difficulty sometimes met with in 

 discovering positive evidence as to the character of bedding. 



*12th Ann. Eep. Ind. Geol. Surv., p. 59. fL. c. 



+ Ind. Geol. Surv., 1859-60, p. 98, 1862. 

 glnd. Geol. Surv., 1872, p. 307. 



