15^ 



SEA-COAST SANDS. 



29 



disposition usually observed in the sea beach formations ; which now from the 

 surface, so that the presence of the Orange Sand ridges is often demonstrated 

 only by the phenomena observed in wells. 



[No. 3.] 



Stratification nf sands in the Sea-Coast Counties. 



The stratification exern plified in the section is exhibited not only in profiles 

 •of the sands overlying the impervious black clays on the "wet meadow" plains 

 adjoining the coast, but also further inland, in the valleys ; in that of the 

 Pascagoula, for instance, as high up as Buckatunna Creek, Wayne county. — 

 These valleys therefore originally formed inlets or fiords, which in, the gradual 

 upheaval of the continent were transformed into rivers, while the gradually 

 retiring surf of the beach left behind everywhere the traces of its action, in the 

 peculiar stratification of the sand. 



52. I cannot see the validity of the objection urged by Tuomey himself 

 (Second Kcport, p. 146 and 147) against his supposition, that the accumulation 

 of the southern drift in belts parallel to the shores of the tertiary sea was caused 

 by the checking of the velocity of the drift currents as they entered the sea. The 

 very fact of currents conveying great volumes of ice-cold fresh water, coming 

 from the land, would naturally cause all living creatures to retire seaward as 

 early as convenient, and since the deposits themselves were formed by those 

 currents in their rear, there appears to be nothing surprising in the fact that 

 they do not contain any marine fossils. In a shallow sea, whose water would be 

 very perceptibly freshened by such an enormous influx, even the influence of the 

 differences of specific gravity might be reduced to a very small item by the 

 balancing influence of differences of temperature, acting in the opposite direc- 

 tion ; thus rendering unnecessary the assumption of a temporary redepression 

 of the land as suggested by Tuomey. That the gradual upheaving process was 

 continued up to a late date, and that currents more slow and deliberate than 

 those which deposited the drift, covered the country for some time after the 

 latter period, seems to be proved by the two superincumbent formations, the 

 Bluff (327), and the Yellow Loam (332) ; since both the latter formations have 

 availed themselves, in their deposition, of valleys previously excavated into the 

 Orange Sand itself. 



