24 GEOLOGY. 



State. It is no less so for its varied and abundant mineral 

 wealth. Occupying the extensive belt that lies between the 

 western base of the Blue Ridge and the western edge of the 

 tertiary and cretaceous formations, it embraces that portion of 

 the State which unites in the greatest degree a salubrious cli- 

 mate with a fertile soil. Descending from the elevated table 

 land of the Chattahoochee, by a succession of undulating and 

 parallel ranges of hills to its junction at the heads of naviga- 

 tion, with the lower formations, it presents a series of valleys 

 of an originally rich soil, and abundantly supplied with streams 

 of pure water. Interesting as this formation is to the mineralo- 

 gist, and in reference to its influence on national wealth, to 

 the geologist it presents, from its very uniform and simple con- 

 stitution, but a limited field for remark. The rocks which 

 compose it are, with but few exceptions, of a stratified or 

 gneissoid kind. The western portion consists principally of 

 rocks of a schistose character, as talcose slate, chloritic slate, 

 and hornblende schist ; whilst the gneissoid rocks prevail to- 

 wards the east, in the form of micaceous, felspathic and sien- 

 itic gneiss. The exceptions to the stratified character are but 

 few. The most remarkable of them is the Stone mountain in 

 De Kalb county, which is composed of a compact light-coloured 

 granite, of uniform composition, and which presents to the eye 

 one enormous rock, of a dome-like form, towering above the 

 surrounding plain like a huge boulder. Several quarries of a 

 crystalline primitive marble, are found in this formation. In 

 Cherokee county, statuary marble is met with ; and in Hall 

 and Habersham counties, darker marbles of excellent quality 

 occur. 



A narrow, but extensive belt of elastic sandstone (Itaco- 

 lumit)* runs from Hog mountain, in Hall county, to the N. E. 

 corner of the State, in Habersham county. At Col. Young's, 

 nine miles from Gainesville, it appears at the summit of the 

 mountain ridge, and presents an outcrop of several hundred 

 feet. As this rock is regarded as the matrix of the diamond, 

 it may be expected, from its great extent, that the dozen that 



* The public is indebted to Dr. W. C. Daniell for an accurate survey and 

 map, made under his direction, by F. Schreiber, of this formation. 



