IOWA CAMBRIC SUCCESSION 
325 
beneath, the Oneota Dolomite. As a terranal title New Rich¬ 
mond drops out of Iowa geological nomenclature. 
In Calvings report on Allamakee County,®^ and in his report on 
Winneshiek County,®® as well as in Leonard’s report on Clayton 
County ®® the words New Richmond should be changed to Jordan. 
In the latest geological report®® on the lower Minnesota River 
valley, issued by the Federal government not all of the early mis¬ 
takes in correlation by Winchell appear to have been corrected by 
Sardeson and there may be other errors in identifications of ter- 
ranes with those of other states. The very data which are there 
published demonstrate the misinterpretations that are made else¬ 
where by other workers. The best drill-well sections in the Min¬ 
neapolis quadrangle seem to show conclusively that the Oneota and 
Shakopee Dolomites are not part of the same formation. The 
thick dolomite beneath the Jordan Sandstone, which is clearly re¬ 
vealed in good well records, is wholly unaccounted for. Neither 
is the Ordovicic age of the Oneota Dolomite proved by the evi¬ 
dence adduced. That the Shakopee Dolomite should carry some 
Ordovicic forms does not preclude its ranking in the Cambric suc¬ 
cession. Here, again, under the illusion that it is erecting some¬ 
thing new under the sun the mischievous consequences of Ulrich’s 
forced attempt to found another system out of the Early Ordovicic 
and Late Cambric beds is brought home. 
The topmost member of the Cambric section was especially 
noted so early as 1850, by Shumard,®^ who well described the 
formation as it outcropped in front of the village of the Indian 
chief Shakopee, on the Minnesota River. A quarter of a century 
later the terrane was defined and christened the Shakopee Lime¬ 
stone.®^ Because of its position between the Peter Sandstone and 
the Oneota Dolomite its identity was always readily inferred. In 
parts of Wisconsin it was unrepresented according to Twenhofel 
and Thwaites,®® it probably having been locally eroded before the 
57 Iowa Geol. Surv., Vol. IV, p. 62, 1894. 
58 Ibid.. Vol. XVI, p. 68, 1906. 
59 Ibid., Vol. XVI, p. 241, 1906. 
60 U. S. Geol. Atlas, Folio 201, 1916. 
61 Geol. Rept. Wisconsin, Iowa and Minnesota, p. 682, 1852. 
62 Minnesota Geol. Surv., Second Ann. Kept., p. 139, 1874. 
63 Journal of Geology, Vol. XXVI, p. 616, 1920. 
