88 



LIMESTONES OP RED CEDAR, 



mile, with a local northerly dip, containing Spirifer euruteines. On Section 15, on 

 the left bank, there are 30 feet of regularly bedded limestone, surmounted by a 

 bench of concretionary limestone. On Section 16, one bed is charged with Terehra- 

 tula reticularis, and contains also Spirifer euruteines. 



All through Townships 80 and 81 north, Range 6 west, of the 5th Principal Meri- 

 dian, and as far as Section 28, Township 81 north, Range 7 west, wherever the bluffs 

 come up to the river, ledges of limestone of the same character and age present 

 themselves, until they finally terminate in a rugged buttress of the same concre- 

 tionary and brecciated mass that forms the upper part of the section at Iowa City, 

 the coralline beds being found a few hundred yards below, at an elevation of fifty- 

 five feet. 



After passing Section 28, Township 81 north, Range 7 west, low prairie sets in, 

 and no rocks are visible for about twelve or fifteen miles, by the meanders of the 

 river. On reaching a bend where the stream flows very rapidly, near where the 

 line between Sections 28 and 29 of Townships 81 north, Range 8 west, crosses the 

 stream from north to south, a dome-shaped mass of sandstone rests on a white sandy 

 clay. The same kind of rock is said to be in place both on Section 27 of the same 

 township and range, and Section 26, Township 81 north, Range 9 west, of the 5th 

 Principal Meridian. These gritstones belong, in all probability, to the carboniferous 

 group ; but no confirmative evidence was derived from organic remains. 



VTEW ON THE IOWA RIVER. 



After entering Township 81 north, Range 9 west, the hills recede from the river, 

 appearing in the distance mostly as gentle swells of from seventy to one hundred 

 feet high, presenting beautiful sites for farms, in connexion with the rich adjacent 



