IOWA CAMBRIC SUCCESSION 
319 
complex. In view of the recent recognition of definite terranes 
above and below, it now appears best to restore the term Dres- 
bach Sandstone to its original sense. This is done in the late 
Iowa reports.^® 
When the early volumes of the present Geological Survey of 
Iowa were published need was found for a geographic term to 
cover the incoherent mottled sandrocks which were displayed in 
the Mississippi gorge above Lansing. This determination could 
not be made in time for the first report,^® and mention of the 
beds in question was omitted altogether. In the Iowa part of the 
gorge Calvin was unable to decide upon a basal limit, notwith¬ 
standing the fact that he minutely described the upper part of the 
section. 
Several years later Berkey,^^ in Minnesota, without defining 
either the upper or lower limits, proposed the title Franconia 
Sandstone for this part of the Mid Cambric succession as exposed 
at the St. Croix Dalles. This name, after proper definition, 
might be retained were it not for the fact that it was long ago 
pre-occupied for a formation in New Hampshire. It therefore 
becomes invalid. Hence the name Albin Shales is substituted — 
a title derived from the northernmost town in Allamakee County 
where the beds are finely displayed. 
For some unaccountable reason the members of the United 
States Geological Survey unite the Albin Shales with the over- 
lying dolomite. The same error creeps into Norton’s Iowa re¬ 
port.^* 
In proposing the term Allamakee for the nether dolomite of the 
Cambric succession in the Upper Mississippi valley it is with 
full cognizance of the fact that for many years the formation to 
which it is applied has been widely known as the St. Lawrence 
limestone. The latter designation is clearly a misnomer. As 
originally employed by Winchell,®^ in the Minnesota River sec- 
29 Iowa Geol. Surv., Vol. XXII, p. 155, 1913. 
30 Iowa Geol. Surv., Vol. I, p. 23, 1893. 
31 Ibid., Vol. IV, p. 57, 1891 
32 American Geologist, Vol. XX, p. 373, 1897. 
33 U. S. Geol. Surv., Water Supply Pap. No. 256, p. 63, 1911; Ibid., No. 293, 
p. 65, 1912. 
34 Iowa Geol. Surv., Vol. XXI, p. 67, 1912. 
35 Minnesota Geol. Surv., Second Ann. Kept., p. 152, 1874. 
