186 The American Geologist. March, 1892 
(12. Upper. Chert formation ........80’ 250’ 
BURLINGTON. { 13. Tower. Limestone......... a sleye oeee 290° 
Calcareous shale........ 2's oe SOE 35)! 
Kinpen- - (14. Limestone .........5... siaieietere esas 10’ 365! 
LOOK, PEs MALS coc s-t ays ale motets fas eae 560° 
HAMILTON. 16. Limestone (shaly)...... Abner 65 625 ' 
ORISKANY. 17, Sandstone (water)... eee se aoe 20’ 645! 
Nea (18. Limestone (“sandy”)............ 55’ 700’ 
ont ae ?-19"Sandstone ((water)m.c-ceierienee ae ee 37! 737! 
Hupson _—/.90, Cincinnati (Maquoketa) shale... .63’ 800’ 
RIveER. } 
GALENA AND / 5 : ¢ fe Tee 4 : 940’ 
Tea aoa | 21. Limestone, “sandy” below.......140 940 
LOWER (22. St. Peter’s sandstone............ 110’ 1050’ 
MAGneEsiAn-~ 23. Alternating limestones and sand- 
OR OZARK. | stones (Water). 2.5 csen sc cce = oe os o's 735° 1805 
Till.—The drift covering this part of the state belongs to the 
first glacial epoch. It is denominated the lower till and consti- 
tutes the attenuated border of the drift region. It gradually di- 
minishes toward the south and disappears in the vicinity of St. 
Louis. The following section was obtained at the foot of Ex- 
change street on the bluff overlooking the river: 
SECTION II. 
4. Boulders, gravel and sand commingled. Boulders and 
gravel predominating. All more or less cemented to- 
gether by calcareous material. Boulders from 8 to 10 
inches..in diameter... ... See. a0> ee ie eee eee 6 feet 
3. Boulders, clay, gravel, and sand in irregular patches. 
Same as No. 4, but boulders larger, frequently from 2 to 
Gdeetin diameter... sesso eee Boe eeiaio he eae 13 feet 
2. Blue clay, gravel and sand....... mink +\s ee. seas 0/0 wee eo Ogee 
1. Shales of the Geode formation. ........ A OPES a Bre coher | Ldteet 
At the foot of Bank street, one block south, No. 3 was seen in 
contact with the Geode shales. In this division erratic boulders 
predominate, while above in No. 4 limestones are numerous and 
apparently but little removed from their original locality. Frag- 
ments of the St. Louis, Keokuk and Burlington limestones were 
observed. Some of the boulders were greatly exfoliated and de- 
composed. This, together with their cemented condition, has 
been adduced by Chamberlin and Salisbury as evidence of the 
early origin of the border till.* No striated boulders were ob- 
*U.S. Geol. Surv., 6th An. Rep., p. 264. 
