52 BOARD OF AGRICULTURE. 



tertiary period lies another stratum, belonging to the second- 

 ary formation, called the cretaceous or Pedee River marl- 

 bed, bearing fossils which belong to the chalk period of Europe, 

 but poorer in carbonate of lime. On the Pedee River it 

 crops out near the surface, but in boring the Charleston arte- 

 sian well it was struck at eight hundred feet below the 

 surface. 



This casual glance at the geological features of this remark- 

 able region will serve to throw light upon the wonderful de- 

 posits which we are about to consider, and to establish the 

 fact that, in addition to the phosphatic strata, the most valu- 

 able of all, this is one of the most extensive and richest 

 marl-beds in the world ; and when it is understood that these 

 vast deposits of marl are made up entirely of the broken 

 shells of marine animals, living and dying age after age, 

 through the long succession of centuries, every single species 

 of which is now wholly extinct, and that with these dead and 

 cast-off shells, ground up by the action of water and depos- 

 ited on the bottom of the ocean, inclosing throughout their 

 great depths of corals and corallines myriads of teeth, and 

 bones, and vertebras of sharks and other monsters like whales 

 and alligators, that lived in former geological periods, we 

 shall wonder all the more at the mysteries of the creation in 

 storing up, through the slow lapse of time, the means of sup- 

 porting the forms of a higher life which were to come in the 

 development of a wise and beneficent plan. 



Leaving Charleston for the trip up the Ashley River, the 

 phosphate strata are seen to crop out near the surface some 

 six or seven miles above the city, and above that point for 

 ten or fifteen miles or more. In fact, the whole Ashley basin 

 appears to be underlaid with this stratum at a short distance 

 below the surface, and the same may be said of the Cooper, 

 the Wan do, the Stono, the Edisto, and other river-basins, 

 though in some sections the stratum of phosphate rocks lies 

 deeper than in others. The whole region has been appropri- 

 ately called the Charleston basin, extending seventy-five to 

 eighty miles from north to south, and something like fifty or 

 sixty miles in width — an area of from three to four thousand 

 square miles — nearly equal to half the area of the whole State 

 of Massachusetts. 



