178 



irregularly. In the belt of thick drift ^Yhich leads from Benton County 

 southeast to Marion County, and thence east into Ohio, the thickness is 

 probably 200 feet. The portion of the newer drift area to the south of 

 this belt has an average of about fifty to seventy-five feet. A still larger 

 tract extending north from this belt of thick drift as far as Allen County 

 and the west flowing portion of the Wabash, has only fifty to seventy- 

 five feel, with limited areas where its thickness is but twenty to thirty 

 feet. In northwestern White, southwestern I'ulaski, and southern Jasper 

 counties there are several townships in which scarcely any drift appears 

 excepting boulders and sandy deixisits. In nin'tlicrn Indiana the drift is 

 very thick. Its average thickn(>ss for fifty miles south of the north 

 boiuidary of the State is probably not less than 2.^10 feet and may exceed 

 .''00 feet. At Kendallville it is 4sr> feet, and at several cities on the 

 uioraine which leads northeast from Fulton County to Steuben County, its 

 thickness has been shown by gas jjorings to exceed 300 feet. The rock 

 is seldom reached in that region at less than 20O feet. Were the drift 

 to be stripi)ed from the northern [wrtion of Indiana its altitude would be 

 about as low as the surface of Lake Michigan, though much of the present 

 surface is 200 to 300 feet above the lake"' 



TOPOGRAPHY. 



The stirface of Indiann presents no great diversity of t;ip(igrai)lii(' 

 features. The elcv.-itimi above sea level ranges from .■'>1."! feet at the jnnc- 

 tion of the Ohio .-ind Wai>asii rivers to almut l,2sr» feet, in the southern 

 jiart of Randolph County. II is on this height of land that both the 

 east, and west forks of White Kiver liave their soui'ce. The average 

 elevation of the State is aliout Tco feet. The greater part of the State is a 

 jilain of accumulation. North of the glacial l)oundary iinicli of the area 

 has a comparatively level surface, or oidy gently niidulaling. In the 

 northeiistern part of the State are some considerable bills and ridges, 

 formed frf)m the coarser materials and large boulders of the drift. These 

 morainie ridges, some of which reach a height of 200 fe(>t, stand out in 

 sharp contrast to the level area of old Lake Maumee on the south, and 

 to the sand covered area to the west. Here on the west, the Kajikakee 

 Marsh with an area of 1,000 s«iuare miles is very flat, and the are.a to 



» See U. S. G. S. Monograpli XXXVIII, I.cvcr.'tt. Also "Studios in Indi.Tiia 

 Geography," Di-jer, pp. 29-40. 



