STE. GENEVIEVE FORMATION 
245 
FEET. INCHES. 
2. Sandstone, fine-grained, light gray above but 
yellowish bel6w, soft, bearing rounded 
and subangular blocks of gray dolomitic 
limestone 21 6 
(disconformity) 
LOWER ST. LOUIS : 
1. Limestone, brecciated, gray to buff, imper- 
fectly dolomitized, exposed, to level of 
track 16 
In the exposures on Eeed creek the Pella beds are exceptionally 
well developed. A remarkable section exhibiting both the Pella 
and the whole of the St. Louis as developed in Iowa, appears 
in the south bluff of the creek about three-fourths of a mile 
above its mouth (N. E. 1 / 4 , N. E. 14 , Sec. 14, T. 68 N., R. YIII 
W.). The succession, as measured near the middle of the bluff, 
is as follows: 
SECTION IV. 
FEET. INCHES. 
11. Drift. 
PELLA : 
10. Limestone, light gray, compact to subcrys- 
stalline, some layers lithographic-like and 
breaking with conchoidal fracture; layers 
1 inch to IV 2 feet thick, separated by 
shaly partings which are locally highly 
fossiliferous; ‘in places exhibiting stylo- 
lytic structure; becoming shaly in lower 
portion and grading downwards into the 
bed below; locally brecciated in part 21 6 
9. Shale, bluish, argillaceous to calcareous, of 
variable thickness due to mashing 3-6 
8. Limestone, light gray, compact, in thin, ir- 
regular layers with shaly partings 9 
7. Sandstone, bluish, fine-grained, rather soft, 
bearing rounded and subangular pebbles 
of compact gray limestone 6 
6. Limestone, gray, compact in middle but 
subcrystalline above and below 4 
5. Sandstone, bluish, fine-grained, calcareous, 
massive, bearing rolled chert fragments 3 
(disconformity) 
UPPER sT. Louis: 
4. Limestone, buff, dolomitic, arenaceous 6 
3. Limestone, buff, dolomitic, massive 2 9 
2. Limestone, buff, dolomitic with small ir- 
regular remnants and blocks of compact 
gray limestone, slightly brecciated 9 
(disconformity) 
LOUVER ST. LOUIS : 
1. Limestone, buff, dolomitic, badly mashed 
and brecciated, shaly in lower portion ... 28 
