IOWA ACADEMY OF SCIENCES. 
105 - 
2. The Coggon beds, as described by Professor W. H. 
Norton in the reports of the Iowa Geologial Survey, 
overlie the Gower stage of the Silurian, and &re immedi- 
ately beneath the Otis beds of the Wapsipinnicon stage, 
the lowest Devonian terrane recognized in Iowa. The 
lithological affinities of the Coggon are with the Niagara,, 
but the very meagre fauna inclines rather toward the 
Onondaga limestone of the Devonian. The specimen from 
Bieler’s quarry in Cedar county, was analyzed by Miss 
Herrin ton. 
CaCOs 58.2 percent. 
MgCOs 39.5 
FeaOs and AI 2 O 3 0.9 
SiOs 1.2 
Total 99.8 per cent. 
This is not a true dolomite, but more nearly approaches 
it than the rock described in 1. 
3. The Gower stage as defined by Professor Norton 
includes two distinct lithological types: A hard crystal- 
line rock used extensively for lime, and hitherto known 
as the LeClaire limestone; and a granular, evenly-bedded 
rock which furnishes the best building stone in the state. 
This was until recently designated as the Anamosa beds, 
which have usually been assigned rank as a distinct geo- 
logical formation; but the Iowa Geological Survey in its 
recent reports, has taken them to be but a lithogical phase 
of one formation. The name Goiver has been assigned 
them from the township in Cedar county in which the 
important Bieler quarries are situated. Both types of 
rock are found in the Bieler quarries. The specimen of 
the granular laminated building stone was analyzed by 
Miss Herrinton. It varies only slightly from a true dolo- 
mite. 
CaCOs 
MgOCE 
Fe 20 s and AI2O3 
Si0 2 
Total 
56.4 per cent. 
42.6 
0.7 
0.4 
100.1 per cent. 
