57 



present day thrown up on the neighboring beaches in 

 great abundance, and he had dredged some of them at a 

 depth of from five to thirty feet at Beaufort, N. C. 



After their deposition the carbonate of lime of the shell 

 marl of the Eocene rocks had been replaced by phos- 

 phate of lime. How this had been effected, and whence 

 the phosphate of lime was derived, was a question still 

 unsettled by chemists. He alluded to the theory of Prof. 

 Shaler that this phosphate deposit had been formed at the 

 bottom of the Gulf Stream, which, according to that geol- 

 ogist had probably flowed over the site of the present 

 phosphate beds ; and in opposing the theory suggested 

 that the phosphate beds were deposited in shallow water, 

 perhaps lagoons as suggested by Prof. Holmes, as they 

 rested in a shallow water deposit above alluded to. There 

 was no apparent evidence, as well shown by the facts pub- 

 lished by Tuomey in his geological survey of South Caro- 

 lina, of a depression of the coast. On the other hand there 

 is no apparent evidence of glacial action on the coast, 

 since the Quaternary sands are marine or aerial, and 

 Tuomey states that he has nowhere in the state of South 

 Carolina seen any angular blocks, nor a pebble a foot in 

 diameter. Moreover, the life of the Quaternary in this 

 state indicated even a warmer climate than at present 

 .obtains. 



Since these remarks were made, he had met by acci- 

 dent with the paper by Desor, than whom no one can speak 

 with greater authority, in which he has made a compari- 

 son * between the glacial marine beds of the North and 

 the marine coast deposits of the Southern states, parallel- 

 izing the deposits in a masterly manner. His remarks 



* Post Pliocene of the Southern states and its relation to the Laurentian of the 

 North and the deposits of the valley of the Mississippi. By E. Desor. American 

 Jour. Sciences and Arts. 1852. Vol.14, p. 49. 



ESSEX INST. BULLETIN. in 8 



