198 
IOWA ACADEMY OF SCIENCES. 
There are many other facts* which point to the inaccuracy of 
these early conclusions. Within the last fifteen years espe- 
cially, deep boring has been prosecuted at various points in the 
field at hand. Other holes have been drilled and, although 
there are not many carefully kept records of any of these, each 
served to indicate the existence of very different conditions 
from those which had hitherto been believed to prevail. At 
Council Bluffs, Glenwood, Red Oak, Villisca; Riverton, Shenan- 
doah, Clarinda, Atlantic, and other cities east of the river and 
at Plattsmouth and Omaha, across the Missouri, holes from 300 
to 2,000 feet deep have been bored, in the attempt to find work- 
able coal veins or artesian water. At the first named point on 
the grounds of the School for the Deaf, a well was put down 
1,080 feet, and an examination of the drillings shows that 
strong clay shales, doubtless Coal Measure, prevailed to the 
bottom, and no bituminous vein whatever was penetrated. 
Call* has reviewed the sequence at the Glenwood deep well 
and put the base of the UjDper Coal Measures at 517 feet from 
the surface, thus allowing a thickness of only 154 feet to this 
geological division. A recent careful examination of the drill- 
ings reveals the fact that the measures for a great distance 
below this level are evidently in no manner different from those 
above, and such beds, mainly argillaceous shales, extend to 
more than 1,400 feet below the surface. It would certainly be 
more consistent to consider as belonging to the Upper division 
all above that point and to concede the remainder of the section 
to be “Middle” and Lower, or Des Moines series. The last 500 
feet, as shown by the samples, is made up of very fine sands, 
white to yellow in color, with an occasional layer of clay shale. 
The Des Moines terrane or Lower Coal Measures has been 
assigned a thickness of about 400 feet by Keyes f, hence if the 
division maintains its thickness 'throughout the southwest, as 
declared by White J, and its thickness be added to that of the 
Upper Coal Measures at Glenwood, then the evidence would 
tend to show that the Lower Carboniferous beds were nearly 
reached in the 2,001-foot well. Yet at the same time it would 
seem more natural for the fine-grained shales to be prevalent 
in this southwestern area and not the fine sandstones, since the 
field lies within the central portion of the great Carboniferous 
*Proc. Iowa Acad. Sci., vol. I, pt. ii, pp. 60-63. 1892. 
tlowa Geol. Surv., vol. II, pt. iii, p. 118. 1894. 
$Geol. Iowa, vol. I, p. 243. 1870. 
