14 GEOLOGY. 



and money, should impress upon the people of Georgia the 

 high value attached by intelligent minds to such inquiries, the 

 results which have followed from them of important practical 

 utility, as well as of high national character, should stimulate 

 us not to be behind our sister States in the execution of a work 

 demanded equally by the interests of the community and the 

 claims of an advanced state of civilization. 



No state in the Union presents a richer field for the geolo- 

 gist than Georgia. With a territory embracing the southern 

 extremity of the great Atlantic chain of mountains ; extend- 

 ing across them to the N. W. into the valley of the Mississippi ; 

 running to the S. W. into the cretaceous slope of the Gulf of 

 Mexico, and occupying along its eastern boundary a wide belt of 

 tertiary, it contains most of the important geological formations. 



Commencing at the Atlantic ocean, and spreading out 

 from 100 to 150 miles to the west, an extensive plain of a ter- 

 tiary formation, rises from the level of the sea, and gradually 

 swells up to a height of about 500 feet, at a line passing near 

 the heads of navigation of the rivers Savannah, Ogeechee, 

 Oconee, and Ocmulgee, where it meets a primary formation. 

 Between the Ocmulgee and Flint rivers it leaves the primary 

 formation to the right, and rests on the cretaceous, from' a point 

 nearly midway between Macon and Knoxville, by a line run- 

 ning in a S. W. direction to another point between Petaula 

 creek and Fort Gaines on the Chattahoochee river. 



Bounded by the last mentioned line to the S. E., and by 

 the southern edge of the primary, as indicated by the heads of 

 navigation in the Flint and Chattahoochee rivers, the creta- 

 ceous formation extends from Alabama into Georgia, forming 

 an acute triangle. The ■primary, or non-fossiliferous, bounded 

 to the east by the tertiary and cretaceous formations, as described 

 above, crosses the State from N. E. to S. W., with a width of 

 160 miles at the northern limit, and 100 at the southern. The 

 Blue Ridge range of mountains passes near its western edge, 

 and forms the most elevated land of the State, varying in 

 height from 1200 to 4000 feet. From this crest there is a gra- 

 dual descent to the east, by a series of parallel and undulating 

 ridges, until the tertiary plain is reached. On the west the 



