46 FLnORSPAR DEPOSITS OF SOUTHERN ILLINOIS, [bull. 255. 



deepest, the sliaft now beino- down oOO feet, and for many years it 

 Avas the only important producer of fluorspar. It is located about 

 a half mile back from the Ohio and slightly farther from the Fair- 

 view mine. As already stated, it is believed to be on a different vein, 

 though the ore l)ody continues from one mine to the other. 



The hanging- Avail consists of the same sandstone as at the Fair- 

 A'iew. Sami^les taken from below the surface shoAV that it has been 

 altered to a hard quartzite by the deposition of silica between the 

 sand grains. The foot wall at the liottom of the shaft is a fine- 

 grained " plucky " limestone, wdiich Mr. Ulrich considers to be 

 l^robably St. Louis. At the surface the foot wall is not exposed, 

 l)ut from general relations it is presumed to be Ste. Genevieve. At 

 a shaft across the road and to the northeast of the main working 

 shaft, the dump shows fragments of limestone of possibly Tribune 

 or Birdsville age, but it is impossible to determine the relations. 

 Still farther to the northeast sandstone covers the whole surface. 



The shaft is 300 feet deep, and deA^elopment has been carried both 

 to the northeast and to the southwest wath underhand stoping. The 

 vein is vertical and the walls Avhere uncovered are well defined. The 

 hanging wall is extensively exposed and shows numerous striations, 

 which are horizontal. The foot wall is usually covered by a thick 

 body of calcite. 



The vein stuff consists essentially of fluorspar and calcite, with 

 minor amounts of lead and zinc sulphide and occasional specimens of 

 ])yrite and chalcopyrite. Near the hanging wall there is ordinarily a 

 band 1 to '2 inches thick of the sulphides, but they also occur through- 

 out the fluorspar and intimately mixed with it. On one specimen of 

 the blende a greenish-yelloAV material suggestive of greenockite (cad- 

 mium sulphide) Avas observed, and a small flake of native copper Avas 

 also seen. The sulphides occur intimately intergroAvn and also inter- 

 groAvn Avith the gangue minerals. Along Avater channels the blende 

 is occasionally altered to zinc carbonate, and in druses crystals of 

 (ju.artz occur frequently. No special order of deposition of the sul- 

 phides can be made out, and no differences in character with depth are 

 apparent, either in them or in the fluorspar. The fluorspar occurs in 

 great thickness and makes up the greater portion of the A^ein. This 

 is usually 10 to 12 feet wide, but slopes 26 feet Avide are now^ open. 

 The Avhole face of such a slope is made up of practically clear fluor- 

 spar, Avith some intergroAvn calcite, particularly toAvard the foot wall. 

 Ordinarily the calcite occurs for the most part back of a facing or 

 fault plane, shoAving striations and separating the cleaner fluorspar 

 froiu the mixed spar and calcite. A thickness of 14 feet of the lat- 

 ter belAveen this facing and the true limestone foot wall has been 

 observed. 



