I860.] 



THE SOUTHEEN PLANTER. 



459 



Perpendicular Section of Poor Post- Oak Land — In Forest. 

 Surface Soil — Clay. 



Sub-soil and lower earth — yellowish clay. 



Lower and main body of marl — bluish, compact and rich. 



The operation of the violent current of 

 the flood was to wash away and remove com- 

 pletely from such places as this, all the much 

 softer parts of the upper marl — leaving the 

 harder parts, as seen in the now remainin.e; 

 protuberant eminences. Next followed, after 

 the water had become nearly tranquil, its 

 letting fall its last borne sediment of the 

 purest and lightest clay, which deposite first 

 filled the deeper hollows and next covered 

 the highest parts of the marl, and next 

 formed the upper bed and the surface, as 

 they now exist. And in such places, there 

 ■was so little intermixture of the then hard 

 though irregular surface of the marl, (as it 

 was washed clean, and left remaining, by 

 the violent flood,) with the subsequently de- 

 posited clay, that even now there is no car- 

 bonate of lime in the clay within two inches 

 above the soft lime-rock. 



But elsewhere, and in all the now rich 

 and deep black (or " prairie") lands, there 

 was a diff"erent operation, and diff'erent man- 

 ner of formation of soil. There, either the 

 loosened and disintegrated lime-rock was 

 partly left, as calcareous gravel, or this 

 gravel was again deposited, after being 

 swept from places where the current was 

 too violent to leave any such loosened matter 

 remaining in its original place. The inter- 

 mixtures of this calcareous gravel with the 

 fine clay subsequently deposited, would be 

 sufficient to provide material for the deepest 

 and richest of soils, with the subsequent aid 

 of vegetable growth to provide organic mat- 

 ter. The remains of the calcareous gravel 

 are still to be seen everywhere in exposed 

 lower sections of the rich black soils, lying 

 usually from one to three feet deep over the 

 solid upper calcareous rock, and intermixed 



with black soil, which extends from that 

 rock to the surface of the land. In the 

 later time of the subsiding flood, when 

 greatly lessened in volume and in force, and 

 divided into diff'erent smaller currents flow- 

 ing through the deeper channels afforded by 

 the bottom, the water would continue to let 

 fall its burden of fine clay sediment, in dif- 

 ferent quantities according to the depth, 

 and the quicker or slower motion of the re- 

 duced waters. Wherever this pure clay 

 sediment was deposited on the clean-washed 

 and hard lime rock, and of sufficient depth, 

 it served to make the existing patches of 

 " post-oak" soil — which is either improved, 

 or not, by subsequent admixtures of. the 

 lower lime-rock, and is, consequently, either 

 rich or poor, according to th(i natural facili- 

 ties for, or obstacles to, such intermixture of 

 the lower lime with the upper soil. This 

 very pure and close clay, after it had be- 

 come dry soil, or lower earth, whether inter- 

 mixed with lime or separate, would neces- 

 sarily be almost impervious to the downward 

 filtration of rain-water — and equally, or still 

 more impervious is the thick calcareous bed 

 below to the passage of descending rain- 

 water, or to the ascent of the fountain water 

 confined below the thick and impervious bed 

 of lime-rock, and pressin<j upward for escape. 

 With these physical conditions, of nearly 

 impervious upper and lower beds, it is easy 

 to trace and to understand the causes of the 

 remarkable peculiarities of this country, in 

 the entire absence of natural springs and of 

 permanent streams — and of the waxy, ad- 

 hesive qujility of all the surface soils and 

 subsoils and lower earth, when thoroughly 

 wet by rain. This remarkable quality of 

 the soil, which is the great evil of tliis 



