Kindle — Niagara Domes of Northern Indiana. 463 



stone in the quarry at the north side of the town is a soft 

 saccharoidal, nearly pure white stone, while at the Bowers 

 quarry, one-third of a mile to the northwest, the rock at appar- 

 ently the same horizon is a very hard gray dolomitic limestone. 



The paleontological data for the correlation of the beds 

 under discussion with the Niagara of New York was presented 

 in a previous paper* by the writer. The beds appearing at the 

 localities then described are identical in faunal and physical 

 characters with those occurring elsewhere in the northern 

 Indiana area. It appears therefore desirable to continue to 

 use the term Niagara, which has long been applied to the dolo- 

 mites of northern Indiana. 



Structure. — The general structure of the Niagara of northern 

 Indiana is that of a broad arch with gently sloping sides trend- 

 ing northwest and southeast. It represents a northwestern 

 extension of the Cincinnati geanticline. Its axis, approxi- 

 mately 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, Jas- 

 per, 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 Michi- 

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

 toward the southwest or south. The following table shows 

 the elevation of the top of the Niagara A. T. along a line 

 approximately at right angles to this axis, extending from 

 Crawfordsville to Auburn, Indiana, a distance of 140 miles. 



Crawf ordsville 8 1 A. T. 



Frankfort 463 



Kokomo • 778 



Wabash 652 



Columbia City . . 599 



Auburn 50 



The arch described above is not the " Wabash arch " of 

 Gorby, which apparently was supposed by its author to follow 

 the Wabash Yalle} T in eastern Indiana. The tilted beds which 

 were cited as the evidence of the " Wabash arch " will be 

 shown in another part of this paper to be independent of the 

 above described arch in origin. 



The figures given above are based upon gas well records 

 published by the Indiana Geological Survey, f in the northern 

 Indiana area. 



*This Journal (4). xiv, pp. 221-224. 



fl6th Ann. Eep. Ind. Geol. Surv., pp. 217-218. 



