GEOLOGY. 313 



occupy a trough nearly in the central portion of the state, and extending from, 

 Oxford, near the northern boundary, to a point some six miles across the 

 boundary of South Carolina. There is another small belt, similar in structure 

 and conformation, in the north-western part of the state. Red, grey, and drab 

 sandstones alternate with calcareous shales, bituminous slates, and coal seams. 

 Beginning at the lowest in the series they occur in the following order : 

 The stratum on which they rest is a bed of conglomerate so hard that it is 

 used for mill stones. The pebbles of which this is composed are mostly 

 of quartz, derived from the Taconic series below. In the county of Chatham 

 this bed of conglomerate attains a thickness of at least sixty feet. Upon 

 this immediately rests the first of the Permian rocks, a red sandstone occur- 

 ring in belts from one to three feet thick, separated by marls. The aggregate 

 thickness of this stratum reaches in some spots 1,800 feet. The next series 

 consists of shales, calcareous and bituminous, interspersed with belts of 

 softer materials. Among these shales are found beds of bituminous coals of 

 a very fine quality. This coal has 4^- per cent, of volatile matter, makes 2 

 per cent, of ash, and forms excellent coke. The thickness of this series was 

 given at 800 feet. The third series consists of beds of hard and soft sand- 

 stone the latter properly called marls. His object was now to state facts 

 which will show the position of these rocks. They rest upon sandstones 

 which contain carboniferous fossils, and must, therefore, be more recent than 

 these. There is evidently a great hiatus between the rocks underlying and 

 the series now in contemplation. Now, what are the ages of this series ? 

 The Permian and Triassic. What is the evidence of this ? Facts derived 

 from the peculiar characters of the fossils found in them. The most import- 

 ant of these fossils .are Saurians, and that type which is considered character- 

 istic, namely, the Thecodent Saurians of Europe those which are found in the 

 Bristol conglomerate of England, belonging to the lower part of the Permian 

 system. The teeth of these Saurians are in sockets, the vertebras are peculiar 

 in being concave at both ends, and constricted at the sides, which are cha- 

 racteristic of the Bristol Saurians. The ribs are double headed ; and in the 

 specimens now exhibited of the vertebras, the impression of this double head 

 of the rib was distinctly visible. It is clear that these Saurians were highly 

 organized, though this was matter not now to be considered. He called 

 attention again to the fact that the teeth were in sockets, and of these teeth 

 he had three or four species, ah 1 of which he considered as being the same 

 with the Clepsyossurus Pennsylvanicus, first discovered and named by Isaac 

 Lea, Esq. These specimens were found, some imbedded in the coal and some 

 hi rock, so hard that acids were necessary to extract them. In one of the 

 specimens two vertebrae are in their natural position. One tooth he con- 

 sidered that of the Palaeosaurus ; another specimen he considered to be plates 

 of the head of the Archasgosaurus, now found for the first tune in this 

 country. The only specimens found hitherto are from the Saarbruck beds. 

 This, though of the same genus, is probably of a different species. The other 

 fossils are of a minute Cypris, which occurs in the slates of Saxony, similar 

 in character and age. Drawings of a variety of plants found in these coal 

 measures were shown. Leaving this series of shales, we come to drab- 



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