BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 29, pp. 393-398, PL. 20 SEPTEMBER 30, 1918 



FLUOESPAR IN THE ORDOVICIAN LIMESTONE OF 

 WISCONSIN ' 



BY RUFUS MATHER BAGG 



(Read hefore the Society December 29 j 1917) 



CONTENTS 



Page 



Introduction 393 



References by other observers 393 



Location of the quarries and glacial deposits therein 394 



Mode of occurrence of the minerals 394 



Origin of the fluorite 396 



Introduction 



Fluorite was discovered last summer by the writer while examining the 

 galena limestone quarries at Neenah, Wisconsin, when on a field excur- 

 sion with the geological students of Lawrence College. Since this min- 

 eral has never been mentioned as occurring in the Ordovician of this 

 State, and also because its apparent absence has been the repeated cause 

 for especial mention in various State geological reports, it seems worth 

 while to call attention to this discovery. 



References by other Observers 



Prof. J. D. Whitney,^ in discussing the minerals of the "lead region" 

 in 1862, gives the following description of fluor : 



"The element fluorine seems to be very scantily and irregularly distributed 

 through the Paleozoic rocks of the Northwest. Even where these have been 

 partially metamorphosed by igneous agencies, as on Lake Superior, fluorspar 

 is of very infrequent occurrence ; indeed, we are not aware of its having been 

 discovered in more than two or three localities." 



1 Manuscript received by the Secretary of the Society December 28, 1917. 



2 Geology of Wisconsin, vol. i, 1862. Mineralogy, by J. D. Whitney, p. 205. 



(393) 



