358 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA. 



I. The Buff limestone ; the rock analyzed as a whole. Professor J. A. Dodge, 



university of Minnesota. 

 II. The Buff limestone ; the clean calcareous portions with the dark alumino- 

 siliceous bands removed. Professor J. A. Dodge. 



III. The Buff limestone; the dark ahunino-siliceous bands with the calcareous 



portions removed. Dr. W. A. Noyes. 



IV. The lower strata of the Blue limestone; those that crumble on exposure 



to the air. Horace V. Winchell. 

 V. The Buff limestone. Miss M. L. Blanchard. 

 VI. The Buff limestone. W. A. Beach. 



VII. The lower (first) strata of the Blue limestone; probably the same as IV. 

 Dr. Norwood.^ 

 VIII. Galena limestone ; section 9, Spring Valley. Chemist unknown. 



g these 



Paleontologic Characters: The general Section. — In presentin 

 characters of the Lower Silurian rocks (aside from the Saint Peter, 

 already briefly described) many structural features must be detailed 

 which for this very reason were omitted from the paragraph purporting 

 to outline those characters. Furthermore, many facts will be presented 

 which have been discussed more in detail in another place. || The names 

 here given to the second beds are those proposed in the article referred to. 



So far as observed, the lowest Trenton bed of the state, the Buff lime- 

 stone (lower Buff of the Wisconsin series),^) rests conformably on the 

 Saint Peter, save at Faribault, Rice county, where the bed is absent, thus 

 bringing the Blue limestone upon the sandstone and in conformable 

 position. From this point up to the top of the Silurian series for the 

 state there has not been seen either break or unconformity, though the 



* Insoluble silicates. 

 •1 Fe 2 O a and FeO calculated together. 

 % Loss, 3.80 per cent, also reported. 



§ Geological Survey of Wisconsin, Iowa and Minnesota; Owen, ls-"^. p. 72. 



It The range and distribution of the Lower Silurian Fauna of Minnesota, etc, by F W Sardeson . 

 Hull. Minn. Acad. Nat. Sci., vol. iii. no 3. 1892, pp 326-343. 

 \ Geology of Wisconsin, vol. i. 1883, \>. 102. 



