Harper: Explorations in Georgia 1903 145 



an escarpment facing inland, the Grit being everywhere higher 

 than the limestone, doubtless on account of its greater resistance 

 to erosion and solution. In Decatur County, traveling eastward 

 or southward from Bainbridge by rail, one rises about 150 feet in 

 three miles in ascending this escarpment. Elsewhere the differ- 

 ence in elevation is not so great, but always perceptible, as may 

 be seen by examining the profiles of the railroads which pass from 

 one of these regions into the other. From a point on the main 

 Atlantic and Gulf divide a few miles east of Cordele, to the south- 

 western corner of the state, a distance of at least loo miles, this 

 escarpment coincides nearly if not exactly with the divide between 

 the Flint River and all the streams flowing into the Gulf east 

 of it. 



A similar escarpment is said to mark the inland edge of the 

 corresponding Grand Gulf region in Mississippi and Louisiana.* 

 I am also informed by Dr. Eugene A. Smith, who is familiar with 

 the Grand Gulf region of Alabama and Mississippi and has traveled 

 through the Altamaha Grit region of Georgia, that the topography 

 and flora are essentially the same in both. In 1846, some years 

 before the Grand Gulf formation was named, Artemas Bigelow f 

 described and figured some rock outcrops in Baldwin County, 

 Alabama (now mapped by Dr. Smith as being in the Grand Gulf 

 region)^ which must be very similar to the Altamaha Grit outcrops 

 in Georgia. That portion of Alabama is described by Dr. 



Moh 



Alabama" t 



vision of the coast pine belt," but without emphasi/cing its geolog- 

 ical significance. 



The southeastern limit of the Altamaha Grit is ill-defined, for 

 the rolling pine-barrens seem to pass by imperceptible gradations 

 into the flat pine-barrens near the coast. Midway between the 



L 



Savannah River and the Chattahoochee the region under con- 

 sideration is at least sixty miles wide ; but in the vicinity of Climax, 

 in Decatur County, where its limits are pretty sharply defined, its 

 width is not over six miles, and it probably tapers down to noth- 

 ing a little farther on. 



• *See Hilgard, Am. Jour. Sci. III. 2 : 397- 1871 ; III. 22 : 59. 1881 : Dall 

 & Harris, Bull. U. S. GeoL Surv. 84: 161, 168. 1892; Harris & Veatch, Rep. 

 Geol, La. 1899: 96, 1900 ; Veatch, Rep. Geol. La. 1900-02: 156. 1902. 



t Am. Jour. Sci. II. 2 : 419-422. 



i Contr. U. S- Nat. Herb. 6 : iio-liS. 1904. 



