60 BOARD OF AGRICULTURE. 



Professor Francis S. Holmes, of Charleston, to whom is 

 due very much of the credit of discovering and developing 

 this wonderful deposit to its present almost gigantic propor- 

 tions, has given special study to this subject under very favor- 

 able circumstances, and comes to the conclusion that it was 

 never bone, that it was rather of a marine than of a mineral 

 origin, and he maintains that all the remains of land animals 

 which have been found in connection with the phosphate rocks 

 were merely mingled with, and not imbedded in, the nodules 

 in the phosphate basins. 



Let us bear iu mind what has already been said of the great 

 eocene marl-beds, or the great Carolinian bed of marl, lying 

 below the phosphate strata, and which is, as Prof. Holmes calls 

 it, "the foundation of the whole seaboard country of South Caro- 

 lina, composed of the Santee, Cooper and Ashley River marls, 

 extending from North Carolina into Georgia. Before the low 

 country of South Carolina was raised above the level of the 

 ocean, the waves of the Atlantic beat upon the granite hills of 

 Edgefield, Lexington and Richland, as far inland as Columbia. 

 The shallow water of the coast, with its submarine formation 

 of sand-banks, was then, as now, resting on this surface of 

 the great marl formation, of the eocene age. Both were below 

 the level of the ocean, exposed to the degrading influence of 

 the waves, and bored by mollusca and other marine animals ; 

 that is, the upper surface of the marl-bed was washed into 

 deep cavities and holes bored by these animals, and honey- 

 combed to the depth of five or six feet. This is its condition 

 off Charleston harbor at the present time, and, wherever the 

 surface of the bed inland has been uncovered, it is found 

 irregular and broken. From the coarsely honey-combed sur- 

 face of this mother-bed fragments were being continually 

 broken off by the waves, rolled over the sand-beds, which 

 wore off their angular edges, and finally deposited them in 

 immense masses in the great hollows or basins below the ocean 

 level. It did not require a very long time nor much friction 

 to reduce these comparatively soft lumps of marl rock to the 

 rounded or nodular forms they now have. Every gale drove 

 them further and further upon the submarine beach, until, at 

 last, they were deposited in the lagoons or basins formed within 

 the sand-reach of the coast. The next great change was the 



