4Ct THE LOWER PINE BELT, OR SAVANNA REGION. 



and the broad Ijut slow currents of the tortuous streams never free the 

 swamps and lowlands of their superfluous water. So level is the country 

 and so abundant the supply of water, that the engineering skill and out- 

 lay required .to perfect its drainage would, at comparatively small addi- 

 tional outlay, render the larger part of the surface susceptible to cultiva- 

 tion l)y irrigation. In connection with drainage and the embankment 

 of the rivers, the assertion is frequently made, that such works are less 

 ])racticable now than formerly, when they were attempted in conse- 

 ([uence ot the increased size and frequency of freshets, resulting from 

 cutting down the forests, the chief obstructions to the rapid passage of 

 rain water into the streams. In the absence of records giving exact data 

 on this point, this assertion rests more on the apparent nature of the 

 case than on ascertained facts. On the contrary, nothing can be more 

 certain than that no subsequent freshet has attained the height and ex- 

 tent of the great flood of 1796, known as the Yazoo freshet, and that none 

 has exceeded the May freshet of 1840. 



GEOLOGICAL FEATURES. 



Out-crops of the cretaceous rocks of the secondary formation occur 

 east of the Santee river, in numerous localities in the Lower Pine Belt of 

 South Carolina. Commencing at Little river, in the southeastern corner 

 of Horry county, Prof Tuomey followed these rocks to Mars Bluff on the 

 Great Pee Dee and to points as far north as Darlington C. H. They make 

 their appearance on Lynches river in about the same latitude, and were 

 traced by Mr. Ruffin as far west as Kingstree, the countj^ seat of Williams- 

 burg. They consist of a soft marl of a dark gray color, containing (as at 

 Mars Bluff) the remains of belemnites in great number. This marl av- 

 erages about 34 per cent, of carbonate of lime, and rests on a stratum of 

 hard lime or marl stone, which yields 75 per cent, of carbonate of lime. 

 The marl stone in turn rests on a black shale of laminated clay, which 

 rests on beds of sand. The buhr-stone reaches down into the Lower Pine 

 Belt in several localities along its northwestern edge. Prof. Tuomey 

 thought he had traced it as far as the Ashepoo river in Colleton and to 

 Huspa creek in Beaufort county. But as tlie rocks he referred to are now 

 recognized as belonging to th^ phosphate rock formation, the bulir-stone 

 does not extend .so far south as he supposed. 



The body of the Lower Pine Belt is underlaid by marl belonging to 

 that portion of the eocene formation of the tertiary, designated by Mr. 

 Ruffin the Great Carolina Bed. These marl beds are divided into two 

 well-marked groups, known as the Santee marls and as the Ashley and 

 Cooper river marls. The Santee marls are the older, lower and more ex- 



