294 DUE VYOURNAL OF CEOEOGN:, 
and Coal Measure rocks. They now occur in three areas sepa- 
rated by extensive drift-filled preglacial channels. In Van Buren 
county no decisive evidence of similar channels has been obtained, 
but from the great thickness of drift shown by certain well records, 
and from other indications, there is reason to suspect that Fox 
River occupies approximately the position of an older stream. 
Description of sections—In the Illinois Geological Report, Vol. 
I., Worthen has included the Warsaw beds in the Saint Louis 
group and gives the following section of these rocks at Warsaw : 
I. SECTION AT WARSAW. 
1. Concretionary brecciated limestone, - - - = =) 30! 
2. Arenaceous limestone, - - - g - & 10! 
3. Blue argillaceous shales and limestones, - - : So! 
4. Magnesian limestone, — - - - - < : 12! 
82! 
In this section, Nos. 2, 3 and 4 constitute the Warsaw as 
established by Hall. At Keokuk the beds between the Geode 
Shales and the Coal Measures are as follows: 
Il. SECTION AT KEOKUK. 
1. Brecciated limestone; the fragments composed of gray compact 
limestone, sometimes firmly cemented by similar calcareous material, 
in other cases with the interstices filled with green clay, — - 10'—30' 
2. Calcareous sandstone ; blue, weathers brown; in some cases quartz 
grains numerous and coarse, - - - - - 8’ 
3. Blue argillaceous shale with thin variable beds of limestone, the 
latter subcrystalline and fossiliferous, - - - = 250)" 
4. Magnesian limestone, brownish gray; in some places coarse sub- 
crystalline, in others fine and of a bluish color; weathers to a 
yellowish brown, - : - - - - - 4! 
62’ 
The calcareous sandstone (No. 2) corresponds to No. 2 of 
the Warsaw section and is quarried to some extent both above 
and below the city. The limestones of Nos. 3 and 4 are marked 
by the presence of numerous fossils among which the remains of 
Bryozoa, notably Archimedes and Fenestella, are especially 
abundant. The beds 2, 3 and 4, representing the original War- 
saw, have a marked correspondence to the equivalent deposits at 
Warsaw though considerably reduced in thickness. 
