BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 6, pp. 167-198, PL. 2 JANUARY 22, 1895 



THE MAGNESIAN SERIES OF THE NORTHWESTERN STATES 



BY C. W. HALL AND F. W. SARDKSON 



(Read before the Society August 15, 1893) 

 CONTENTS 



Page 



Geographic position of the series. 1()8 



Historic resume 168 



Members of the series 109 



Order of occurrence and thickness 1G9 



Lithologic characteristics 170 



Paleontologic characteristics 171 



The Saint Lawrence dolomites and shales 172 



Localities 172 



Special features 172 



The Redwing section 173 



The '* Mendota limestone " 174 



Faunal characters . . 175 



The Jordan sandstone ] 75 



Localities 175 



Special features 175 



The " Madison sandstone " 176 



Faunal characters 176 



The Oneota dolomite 177 



Localities .. 177 



The name " Oneota limestone " . . 177 



Physical characters 178 



Faunal characters 179 



The New Richmond sandstone 179 



Localities 179 



Physical characters 180 



The Shakopee dolomite 180 



Localities 180 



Physical characters 180 



Faunal characters 181 



The lithology of the series 181 



The sandstones 181 



The shales 183 



The dolomites 184 



Lithologic characters 184 



Silicious segregations 185 



Glauconite grains 185 



Dolomitic conglomerate 186 



XXIV— Bull. Geoi,. Soc. Am., Vol. fl, 1894. (167) 



