564 



EDWARD STEIDTMANN 



Randville. Allen emphasizes this relation of the Hanbury slate 

 as evidence of unconformity with the Curry iron- formation group. 

 No proof of angular discordance between the Hanbury slates and 

 the Curry iron formation seems to have been found by Allen. His 

 recognition of the Loretto slate is based on the fact that on a certain 



forty-acre lot, a few drill holes passed through what he assumes 

 to be the basal Hanbury conglomerate and then through a slate 

 before striking the Curry iron formation. It appears that Allen's 

 revision is based solely on a very local occurrence of a fragmental 

 rock above the Curry iron formation. 



Broderick^ presents a detailed classification of the beds of 

 the Biwabik iron formation in the eastern part of the Mesabi 

 range. He retains Wolff's general classification into Upper slaty 



^ T. M. Broderick, "Detail Stratigraphy of the Biwabik Iron Bearing Formation, 

 East Mesabi District, Minnesota," Econ. Geol., Vol. XIV (1919), pp. 441-51. 



