50 ECONOMICAL GEOLOGY. 



Nos. 5, G, 7 and 8 should probably be included in the Calciferous 

 group, while all below that may be referred to the Potsdam period, 

 and this boring indicates a very rapid increase in thickness of both 

 these formations in their southward extension, over what they attain 

 in Wisconsin and Minnesota, where they form the surface rocks 

 over extensive areas. 



Peddicord's well, near Marseilles, was carried to the depth of 2,189 

 feet, but the flow of water was only one and a half barrels per hour, 

 The following is a copy of the published record of this well: 



Ft. 



No. 1. Drift clay, gravel, etc 2<;<> 



No. 2. Clay shale C5 



No. 3. Limestone 25 



No. 4. St. Peters sandstone 290 



No. 5. Calciferous ? 617 



No. 6. White sandstone 262 



No. 7. Limestone 52 



No. 8. Shale 115 



No. 9. Slato 112 



No. 10. Shalo 9 



No. 11. Limestone 2!) 



No. 12. Sandstone 298 



No. 13. Limestone 4<; 



Total depth 2,189 



The principal flow of water was from No. 12, and it rose within 

 16 feet of the surface until the well was tubed, when it overflowed 



the surface, yielding about 36 barrels per day. The quality of the 

 water is not given. No. 5 is described in the published section as 

 Calciferous, but it probably includes nearly or quite 200 feet that 

 properly belongs to the Potsdam period. The similarity in the lith- 

 ological character of the beds composing these two groups is such 

 that it is impossible to determine, from the material brought np from 

 an ordinary boring, where the stratum belongs, and the thickness of 

 the Calciferous must be determined by its general average at other 

 localities. 



The St. Peters sandstone, and the white sandstone of the Cal- 

 ciferous group, were both found to be water-bearing in the Streator 

 well, the water from the St. Peters coming within 40 feet of the sur- 

 face, and that from the Calciferous within about 34 feet, and the 

 water was reported to be sweet and apparently free from deleterious 

 mineral substances. The water from the Potsdam was brackish and 

 unfit for common use, but rose in a tube to the height of 45 feet 

 above the surface. 



The location of this well Is 40 feet above Lake Michigan and 618 

 feet above sea level. 



