GEOLOGICAL SOCIETY OF LONDON. 



nah, though the country is generally flat, and the structure is ex- 

 posed only in the bluffs. After passing cliffs of horizontal strata of 

 the brick red sand and loam, the first considerable exposure of new rocks 

 was observed forty miles below Augusta, at Shell Bluff, 120 feet high. 

 They consist, in the lower part, or for about eighty feet in altitude, of 

 white calcareous sand, or comminuted shells, passing into solid lime- 

 stone, containing a few quartz pebbles, numerous casts of testacea, 

 and a bed of the huge Ostrea Georgiana. The upper forty feet of the 

 cliff consists of the red loam, devoid of fossils, but considered by the 

 author to belong to the burr-stone formation, and therefore to be an 

 upper eocene deposit. Mr. Lyell concluded, from his first inspection 

 of the organic remains at this Bluff, that the limestone belonged to the 

 eocene series, but it was not till he had had the advantage of Mr. Con- 

 rad's assistance, that he was able to identify a considerable number of 

 the species with characteristic fossils of the well known eocene beds of 

 Claiborne in Alabama. A similar section is laid open at London 

 Bluff, nine miles below Shell Bluff, and two miles further, the oyster bed 

 is exposed, the shells standing out in relief. At Stoney Bluff, the cal- 

 careous strata have quite disappeared, and beds of siliceous burr- stone 

 or mill- stone, containing casts of shells, rest on the red loam. The 

 same rock is also exposed at Millhaven, eight miles from Stoney Bluff. 

 It is evident, Mr. Lyell states, that the mill-stone is subordinate to the 

 great formation of red loam ; for at this point, there likewise occur masses 

 of Kaolin. One mile west of Jacksonborough, is a limestone passing 

 upwards into marl, the surface of which appears to have been denuded, 

 as it undulates considerably, and upon it rests a bed of yellow and red 

 sand and clay, belonging to the burr-stone formation. The fossils 

 hitherto procured from the limestone, are new to American palaeontolo- 

 gists, but Mr. Lyell has no doubt, from their general aspect, that they 

 belong to the eocene period. The limestone and marl, the author is of 

 opinion, constitute the fundamental formation of the region, as proved 

 by the numerous hollows, or " lime-sinks," which occur over its sur- 

 face. All the Bluffs examined by the author below Briar Creek, belong 

 to the beds above the limestone, and are referable, for the greater part, 

 to the burr-stone formation, or the red loam and yellow sand. In some 

 white clays, a little below Tiger Leap, he found fragments of the 'eeth 

 of Myliobates and Lamna, and impressions of bivalves ; and in the sec- 

 tions at Sisters' Ferry, the clay, in places, passes into a kind of Menilite. 

 In conclusion, Mr. Lyell observes, that the part of South Carolina and 

 Georgia, between the mountains and the Atlantic, is known to have a 



