184'6.] LYELL ON THE NEWER DEPOSITS OF NORTH AMERICA. 405 



Note appended by the Authors subsequently to the reading of the 



paper. 



We feel the difficulty there is in supposing the groups of strata 

 marked B, C and D in the section of the Powder Mills Hill to be 

 the same as the strata so marked in the Quarry Hill section. It in- 

 volves several apparent anomalies. Mr. Hopkins suggests that if 

 this is the correct structure, there must exist two transverse faults, 

 parallel to and flanking the railway section, the one between the 

 section and Bidborough Hill, and the other between the section and 

 Brenchley Hill, and that the district between these two faults pre- 

 sents a local structure deviating from the normal structure which 

 is exhibited in the anticlinal ridge of Bidborough and Brenchley 

 Hills. He thus accounts for the origin of this transverse valley, 

 and adduces it as another fact in explanation of the singular trans- 

 verse drainage of the Wealden. 



Should it prove that the shales (E) at the section at the east end 

 of Southboro' Hill correspond with the upper part of the shales (B) 

 in the Powder Mills section, then these latter would form, with the 

 sandstones C and D, the lowest series in the district, underlying all 

 the strata at Quarry Hill. Still however our main argument, that 

 the sandstones at Tunbridge Wells were the representatives of those 

 at Quarry Hill, thus placing them at the top of the Hastings sands 

 division of the Wealden, would hold good, and the hypothetical 

 structure would be the same, but simplified ; for the sandstones would 

 range without break in a slightly undulating and nearly horizontal 

 position from the Wells along Southboro' Hill to Bidborough Hill, 

 to the north of which they would meet with the Quarry Hill fault, 

 and dipping rapidly towards it would disappear below the shales 

 (B), both these strata appearing again at a higher level on the 

 north side of the fault. (See general section, Quarry Hill.) 



2. On the Newer Deposits of the Southern States of North 

 America. By Charles Lyell, Esq., F.G.S. 



In a commun'cation formerly made, I gave a short notice on the 

 Alabama coal-fields ; I now propose to say something, but very 

 briefly, of the newer deposits of the South, the post- pliocene and 

 tertiary, so far as I have examined them in my present tour. 



First, in regard to the post-pliocene occupying the coast and 

 the lowest lands for some leagues inland in Georgia, the marine 

 shells contained in deposits of clay and sand differ in no way from 

 those of the adjoining sea. They are found arranged in groups, 

 littoral and pelagic, as now on or near the shore. Such is observed 

 to be the case in the island of Skiddaway, which is part of the delta 

 of the Savannah river, and in the country between the mouth of the 

 Alatamaha and the Turtle river in (llyini county, (Jeorgia. These 

 marine sandy deposits resemble exactly those which must be now 



