62 GEOLOGICAL FORMATIONS 



the river ; but it rises to view in the southern part of Lewis 

 county, above Quincy. 



For more than 70 miles, from above Quincy to below 

 Louisiana, the Burlington limestone forms an almost continu- 

 ous mural escarpment, capping the high bluffs on either side 

 of the Mississippi river. These bluffs rise to a height of from 

 300 to 400 feet above low water. In many places they form 

 bold overhanging cliffs, with a heavy talus at the base. At 

 the southern end of the escarpment the limestone is every- 

 where underlain by about 200 feet of shale and soft strata, 

 which rapidly disintegrate, leaving the more durable overlying 

 beds standing'out boldly. 



From Quincy southward the strata rise very gradually 

 until the Burlington limestone, which appears a few yards 

 above the water level at that place, has an elevation of more 

 than 250 feet above the river at Louisiana. Below the lime- 

 stone it will be seen from reference to the section that the 

 beds are largely soft shales, which succumb to eroding agencies 

 much faster than the great thickness of heavy compact lime- 

 rock overlying. High hills with precipitous slopes are found 

 there capped by the more indurated layers. They rise in 

 almost vertical walls from about midway up the elevations. In 

 consequence of this, a peculiar and very striking phase of topo- 

 graphy is produced, reminding one very forcibly of the topo- 

 graphical effects in the great driftless area of northeastern 

 Iowa and the adjoining parts of the neighboring states. 



North of Quincy, as has already been stated, the Burling- 

 ton rock dips below the water level of the Mississippi, and 

 does not appear again until just above Fort Madison, in Iowa> 

 while at the city of Burlington the base of the limestone is 

 nearly 100 feet above the low-water mark. At this place the 

 organic remains have received more attention than anywhere 

 else; while the vertical range of the different species has been 

 determined with great accuracy. From this locality, also, the 

 extensive faunas of the Kinderhook were made known and 

 many species described. But more than a third of a century 

 has passed since the investigations of Hall, White and Win- 



