74 
Wisconsin Academy of Sciences, Arts, and Letters, 
The term St. Lawrence limestone was first proposed by N. H. 
Winchell in his 2nd Annual Report, Minnesota Geological Sur¬ 
vey, page 152, 1874, the name being derived from exposures at St. 
Lawrence, Scott County, Minnesota. Here the bed so named con¬ 
sists of hard magnesian limestone layers speckled with green (glau¬ 
conite) with a total exposed thickness of 14.5 feet. According to 
well records given by Upham in his report on Scott County (Minn. 
Geol. Sur. Final Rept. 2, p. 120-121, 1888) this bed may reach 25 
or possibly 30 feet. In 1874 Winchell regarded this outcrop as 
representing the lower division of the Lower Magnesian limestone 
of Owen (subsequently named Oneota, limestone by McGee) and 
as underlying the Jordan sandstone which he viewed as separating 
the two divisions of the ‘‘Lower Magnesian.’’ The name Shakopee 
limestone was given at the same time to the dolomitic formation 
which overlies the Jordan in the valley of Minnesota River. So far 
as the sequence of these three formations is concerned Winchell’s 
original view has been proved correct. But he was in error in 
correlating the Jordan and St. Lawrence with respectively middle 
and lower divisions of the Lower Magnesian. Both of these forma¬ 
tions are pre-Oneota deposits. The Oneota belongs between the 
Jordan and the Shakopee, but in this part of the Minnesota Val¬ 
ley the lower and more important part of the “Lower Magnesian” 
limestone is thin and in places seems to be absent entirely. 
In the 2nd, 4th, and 5th Annual Reports of the Minnesota Sur¬ 
vey the Shakopee is confused at times with the Oneota, and in 
other places it is the St. Lawrence that is regarded as the equiva¬ 
lent of what we now distinguish as the Oneota. In the 2nd Annual 
Report, as said, the Jordan is regarded as a middle member of the 
Lower Magnesian series, the Shakopee as the upper, and the St. 
Lawrence as the lower division. In the 3rd Annual Report the 
name St. Lawrence is in places applied to the whole of the Lower 
Magnesian, the locally developed sandstone (that was later named 
New Richmond sandstone and which Winchell first suggested and 
later claimed to be the same as his Jordan sandstone) being absent 
in such places. “It (the St. Lawrence limestone) constitutes the 
principal portion of the Lower Magnesian” (4th Annual Rept., p. 
33, 1876). That the “St. Lawrence” as used in the 4th Annual 
Report includes Shakopee is evident not only from the thicknesses 
given (“not far from 200 feet”) but is indicated also by the men¬ 
tioned presence in the upper part of the massive algal remains 
