14 
GEOLOGY 
The easy decomposition of the sandstone of this Third Group has given it all sorts of curious 
forms, which have been compared to ruined temples, natural fortifications, natural mounds, or to 
I must add however that Rogers says in the following page : « 1 may here incidentally remark , that 
certain fossils [Posidonomya Keuperi? etc.) wliich I have recently found in a particular division of the New- 
Red Sandstone {Middle Secondary) of Virginia, have led me to infer the existence in that formation, of 
beds corresponding to the Keuper of Europe. A more particular account of this discovery is reserved 
for a future occasion ». This future occasion has not yet come; and until now-, William B. Rogers and 
his brother Henry D. Rogers, regard this formation as Jurassic coal formation. 
In accord w ith the geologist .lames Hall , tlie brothers Rogers refer all the Red Sandstone Formation 
along the Atlantic slope (See: Geological Map of the United States, by Henry D. Rogers, page 32; in 
the Physical atlas of Aatural phenomena: Edinburgh, 1856.) to the Jurassic epoch. Their opinion, how- 
ever , is not explained by H. D. Rogers in a very clear and concise manner. In page 29 , he says po- 
sitively ((Jurassic; represented in Virginia and North Carolina by a group of bituminous coal-measures, 
and in the valley of the Connecticut and on the Atlantic slope, from the Hudson to North Carolina; and 
again , in Nova Scotia and Prince Edw ard Island , by belts of a red shale and sandstone. Triassic and 
Permian , not represented by- any know n American deposits » ; and in page 32 Rogers says : « the Con- 
tinent (North America) embraces an extremely small extent of the Older Mesozoic or Triassic and Jurassic 
formations)). E'urther: « Geographical distribution. — Commencing at the North-East, the first tract of 
Triassic or Jurassic red sandstone, etc.» I call the attention of the reader to the expressions first Triassic 
and Jurassic; and next Triassic or Jurassic; and, or, are two very different words. A few lines fur- 
ther on he says: « The rod rocks of Prince Edward Island pertain probably to both the Coal period 
and to the earliest Jurassic , etc. . . . )) ; and also : « The vegetable fossils in the Connecticut sandstone , 
display such alliances with those of the Jurassic coal rooks of Eastern Virginia as to place the early Ju- 
rassic or late Triassic age of the deposit beyond a question)). — Is Keuper early Jurassic? or Lias late 
Triassic? the author is silent on these two questions. — And also « .... in the Liassic coal rocks of 
Eastern Virginia , etc. . . » ; also « The few organic remains hitherto procured from this Carolina ( Deep 
River) coal field are identical with forms found either in the Virginia Jurassic coal strata, or in the Vir- 
ginia Middle Secondary red sandstone, of nearly coincident Jurassic date«. 
It is difficult to present an age of strata in a manner more ambiguous , dark and empdtee. The bro- 
thers Rogers and James Hall, try their best to suppress the New Red Sandstone formation in North Ame- 
rica; but they do not know exactly what to do with these five or six thousand feet of strata. On the 
Geological Map of H. D. Rogers, the New Red Sandstone is unknown in the Magdalen Islands; on the North- 
East of the Baie des Chaleurs it is colored as Jurassic Red Sandstone, though the Honorable Sir Wil- 
liam E. Logan, Chevalier of the legion of honor, calls it Carboniferous Sandstone. In Prince Edward Island, 
Connecticut valley, New-Jersey, Pennsylvania, Maryland, Virginia and North Carolina, the New Red is 
colored as Older Mesozoic { rZ''saHdsionc. *" Superior it grows older and the New Red is 
1 Matinal. 
colored as Cambrian or] -duroral. In the Prairies, Texas, Rocky Mountains, New Mexico, etc., the New 
( Primal. 
Red, that seems to change its age with Protean facility, has once more renewed its youth and is colored 
as Cretaceous: and sometimes also as Umbral and Vespertine, or, in ordinary language , as Lower Carbo- 
niferous. They have not vet thought of putting the iVew Bed in the Upper Silurian or the Tertiary; I would 
advise these honorable savants to consider if one of these determinations would not be preferable. 
Having visited the coal-basin of Chesterfield County, Virginia, in April 1849. my first impression 
was that the age of the strata was the same as the Keuper ; and in a letter published in the Rulletin de 
la Societd Gdologique de France, tome si.xieme , deuxieme serie, Paris 1849, seance du 18 Juin, page 575; 
