62 



Franklin, Pimple Hill, and the hills north and west of Sparta 

 and Lockwood. 



That further to the southwest commences at the northeastern 

 extremity of Jenny Jump, and follows the southeastern base of 

 this mountain throughout nearly its whole length, beyond which, 

 after an interruption of about two miles, it again occurs near 

 Oxford ; and further still, at intervals, near Concord and David- 

 son, where it is within two miles of the Delaware. Traced lon- 

 gitudinally, the altered rock shows itself not so much in one con- 

 tinuous line, as in a succession of long, narrow, and somewhat 

 detached belts, several of which sometimes lie parallel to each 

 other and closely contiguous. 



The northeastern tract first shows itself at Mounts Adam and 

 Eve, in New York, about five miles beyond the state line, and 

 has its southwestern termination in the neighbourhood of Lock- 

 wood. Over this whole distance, though the altered material 

 exhibits considerable diversity in regard to the imbedded minerals 

 which it contains, yet the main mass of the rock, or the calca- 

 reous paste investing them, retains to a, great extent, a uniform 

 character as to colour and structure. 



When destitute, or nearly so, of the extraneous minerals 

 often diffused through it, the prevailing condition of the rock 

 is that of a white, perfectly crystalline limestone. An extreme 

 degree of developement of the crystalline structure, is when the 

 mass had assumed the condition of rhombic calcareous spar. 

 It is then often semitranslucent, but more frequently it is of an 

 opaque white, and occasionally of a pink hue, resembling some- 

 what reddish felspar. These varieties may be regarded as the 

 altered rock under its most characteristic features, and are to be 

 viewed as exhibiting the limit of alteration of which the limestone 

 has been susceptible by igneous action, where it has been pure, or 

 consisted of little else than carbonate of lime. When of such 

 aspect and structure, the mineral most usually disseminated 

 through it is plumbago, in small brilliant plates, often perfectly 

 hexagonal. Besides this highly developed crystallization, it pre- 

 sents every gradation of crystalline structure down to a finely 

 granular one, and even to what may be termed the subcrystal- 

 line condition, when it often partakes of the colour and texture 

 of the blue limestone, out of which all these varieties have origi- 



