SASGAMOX COUNTY. 307 



Tlie loess covers a large part of tlie uplands to the depth of from six 

 to twenty feet, and is composed of its usual marly beds of buff and gray 

 s;inds and sandy days. Underneath the surface soil at Springfield we 

 usually meet the following succession of beds ; 



Xo. 1. Soil 1 to 2 feet. 



No. 2. Buff colored, silicious clay 2J to 3 " 



No. 3. Very tine gray, marly sand 3 to 4 " 



Xu. 4. Brown drift clays, usually extending down to the bed rock 30 to 40 * ' 



NH-. _ and 3 of the above section may properly be referred to the loess, 

 and at several points in the vicinity of the city, it has been found to 

 contain the characteristic shells usually found in it. I am indebted to 

 Mr. JOSEPH MITCHELL, who has dug many wells in the north-west part 

 of Saugamou county, and in the adjoining portion of Menard, for the 

 following section of the beds usually passed through by him : 



Xo. 1. Soil 1 to 2feet 6 in. 



X'-. -J. Yellow clay 3 



Xo. 3. Whitish ( gray ?) jointed clay, with shells 5 to 8 



Xo. 4. Black mnck, with fragments of wood 3 to 8 



X> >. 5. Bluish colored bonlder clay 6 to 10 



Xo. 6. Gray hard pan ( very hard ) 2 



Xo. 7. Soft, blue clay, without boulders 20 to 40 



No. 3 of this section is undoubtedly loess, and he affirms that this 

 order of succession was invariably observed at many different localities 

 in that portion of the county, the black, mucky soil always appearing 

 immediately below the loess, and varying from three to eight feet in 

 thickness, and always overlaying the true drift or boulder clay. This old 

 soil is probably the equivalent of a chocolate colored band a foot or more 

 in thickness, which lies at the base of the loess in the bluffs at Quincy. 

 In my report on Adams county, published in Vol. IV, p. 45, 1 suggested 

 that the layers of chocolate colored soil at the base of the loess observed 

 there, might be the equivalent of the old Post Tertiary soil penetrated 

 in the shaft at Coatsburg, and in consequence of the absence of true 

 drift deposits at Quincy. it was difficult to fix the relation which this 

 chocolate colored soil might hold to the boulder clays, but the occur- 

 rence of a similar deposit at so many different localities in this county, 

 at the base of the loess, and always above the boulder clays, seem to 

 indicate pretty conclusively that the stratum at Quincy also belongs 

 above the true drift, and to a more recent period than that penetrated 

 at Coatsburg. These two ancient soils, the one at the base of the loess, 

 and the other below the boulder clay, belong to distinct and widely sep- 

 arated periods, and indicate two distinct emergencies of the surface 

 during the Quaternary period, and the prevalence of conditions suit- 

 able for the growth of an arboreal vegetation. 



The boulder clays, or true drift, consists for the most part of brown, 

 gravelly clay, with small boulders. Occasionally, a boulder two feet 



