26 GEOLOGY. 



of water-worn pebbles of quartz and schist, containing particles 

 of gold, the whole resting on an original bed of schistose rocks, 

 similar in constitution and dip to those of the surrounding hills. 

 The quartz pebbles are usually flattened on the sides, indicat- 

 ing their compression in the veins, and are more or less water- 

 worn, as they have for a longer or shorter period been exposed 

 to the action of the currents of water. 

 // Iron is found in abundance, and of great purity, in this for- 

 mation, and Kaolin of a very fine quality. 



Before closing this imperfect sketch, it will not be inappro- 

 priate to notice the agricultural and industrial effects produced 

 by the geological character of the different formations. 



The tertiary formations, wherever they are of a siliceous 

 constitution, show the usual sterility of that kind of soil. Of 

 this character is the extensive plain between the head of tide 

 water and the calcareous formation of the Eocene — a region 

 which very scantily repays the agriculturist for his labour, and 

 seems by nature destined to be appropriated to grazing pur- 

 poses. The river bottoms of this district present a remark- 

 able contrast to the sandy plain. These owe their fertility to 

 the rich washings from the calcareous and primary rocks, 

 brought down by the stream, and are found to be highly remu- 

 nerative whenever inundations can be prevented. 



Near the ocean, where the rise and fall of the tides admit 

 of their being drained and flowed, they form the soils on which 

 rice is cultivated. The yield of this grain, on such lands, pro- 

 bably exceeds that of any other cereal that is grown. 



The beneficial effect of lime is strikingly illustrated in the 

 tertiary plain, in the admirable adaptation of the soil to the 

 production of cotton, wherever this mineral occurs. On reach- 

 ing the line of the calcareous rocks of the Eocene formation in 

 the counties of Burke, Laurens, &c., a marked change in the 

 fertility of the soil is perceived, and it is to the existence of this 

 rock in great abundance, in the south-western counties, that 

 they are found so pi'oductive in cotton. 



In the primary rock formation, the accumulation of the 

 washings of the disintegrated feldspathic and schistose rocks 

 along the lower hills, and in the valleys, has produced a soil 



