194 PROCEEDINGS OF THE ACADEMY OF [1893. 



NOTES ON THE OCCURRENCE OF QUARTZ AND OTHER MINERALS IN 



THE CHEMUNG MEASURES, NEAR THE LINE OF LYCOMING 



AND TIOGA COUNTIES, PENNSYLVANIA. 



BY ABRAHAM MEYER. 



Ascending the " Roaring branch " of Lycoming Creek, the upper 

 Catskill measures may be seen. After passing two or three thou- 

 sand feet of red and gray rocks we reach the upper measures of the 

 Chemung VHIf and VHIe. Below, these dip from 10° to 80° 

 beyond which they are nearly horizontal. 



In these horizontal strata which rise to heights of from one hundred 

 to three hundred feet above the stream, may be seen peculiar undula- 

 tions or rolls, some being slight short curves, others semi-circular, 

 while some form an entire circle Avith the layers concentric. These 

 are most apparent near the base of No. VHIe, in shales and fossili- 

 ferous limestone and iron ore. The rolls differ from the rock, which 

 surrounds them, though the latter follows to a certain extent the 

 convexity of the rolls. 



Near one of these rolls a drift was made in search of ore. On 

 the east side appeared a seemingly vertical wall of dark metamor- 

 phosed fossiliferous rock of considerable hardness, containing much 

 carbonaceous material and iron pyrites, with cavities holding 

 drusy quartz, calcite, chalcopyrite, etc. On the west side was a soft 

 (pyrophyllite) slate, with calcite and quartz crystals near the line of 

 contact. 



In the four or five feet between these was a heterogeneous mixture 

 of hard and soft rocks of varying character, from a soft bluish clay 

 to a very compact quartz resembling novaculite, a breccia together 

 with geodes containing quartz crystals, calcite in the form of dog- 

 tooth spar, pearl spar, chalcocite, chalcopyrite, galena and blende 

 with possibly siderite, fluorite and millerite. 



The quartz crystals are generally attached to the rock in the 

 usual manner ; some, however, are loose and nearly perfect, often 

 smoky and usually containing remarkable inclusions both solid and 

 liquid. There is much carbonaceous material, quite loose and soil- 

 ing anything with which it comes in contact. The shale impreg- 

 nated with this is sometimes metamorphosed into an excessively 

 hard material approaching carbonado in its character. 



