Carter and Lesley.] [May 1, 



10' Fine white sand and pebbles 55' 



10 Blue clay, holding iron balls 65 



10 Fine yellow clay, holding iron balls 75 



Thin bed of solid sandstone which seemed to be Trias- 



sic, perhaps not in situ. 



5 feet of Chester Valley limestone (no more limestone) 80 



Struck top of Potsdam S.S at 90 



Water first struck at about 40' down ; at first, muddy ; soon cleared on 

 standing ; supply soon exhausted by the pump ; merely surface water. 



No more water until depth of 81'. 



Chalybeate water at 81' ; immediately rose in the dry well to within 32' 

 of surface. Pumped this water, 60,000 gallons, during 5 days (steam 

 pump). Then iron water exhausted, and clear water took its place. 

 Iron water evidently came from clay beds holding iron balls ; some of 

 which were brought up by the drill. Well cased (6" iron pipe) to 83'. 



Water stratum evidently lies between the clays and the rock floor. 



l 



Artesian Well in the Mica Schist of Philadelphia. 



Notes by 0. C. S. Carter. 



Drilled by H. W. Kelsey, of the Oriental Bath Co., 1104 Walnut street, 

 Philadelphia, for the supply of the baths. 



Drillings at every 10 ieet examined under a lens ; elements arranged 

 below in order of their abundance in the specimen pumping. No rock 

 seen except mica schist and gneiss. Only traces of feldspar noticed above 

 170. Colorless muscovite mica makes all the strata nearly white from 

 160 to 210. The biotite mica darkens the strata from 210 to 266. No horn- 

 blende seen in any of the pumpings. 



20' Clay, the Philadelphia brick clay to 20' 



46 Gravel (thin layer of clay at bottom) 66 



34 Mica schist; milky quartz, biotite mica, occasional 



speck of muscovite mica, no feldspar 100 



20 Mica schist ; muscovite mica and trans, quartz 120 



10 Mica schist ; biotite, quartz and muscovite 130 



10 Mica schist ; quartz, muscovite, some little biotite. . . . 140 

 10 Mica schist ; biotite, quartz, some little muscovite. . . . 150 

 10 Mica schist ; coarse fragments of quartz and muscovite. 160 

 10 Gneiss ; coarse fragments of pink orthoclase, musco- 

 vite and quartz ; first appearance of feldspar 170 



10 Gneiss ; quartz, orthoclase feldspar and muscovite 180 



10 Gneiss ; muscovite, quartz, biotite, little feldspar 190 



10 Gneiss ; muscovite, orthoclase and quartz 200 



10 Gneiss ; muscovite, orthoclase and transparent quartz 210 



