INTRODUCTION. 
BRIEF VIEW OF THE TERTIARY FORMATIONS OF THE 
UNITED STATES. 
Sr ir. Supercretaceous group, De la Beche. Superior order, Conybeare and 
Phillips. Terrains izemiens thalasiques, Al. Brongniart. 
Each of the great classes is again divided into a number of 
subordinate deposits, denominated formations , of which the 
Tertiary appears to possess three, called, in Europe, the Upper 
Marine , London Clay and Plastic Clay formations. The last 
two of these names are very exceptionable, the one being local 
and the other far from descriptive. It is therefore proposed in 
the following work to speak of the three formations according 
to the order of their succession, and, at the suggestion of a 
friend, to call them the Upper Tertiary or Upper Marine, the 
Middle Tertiary and the Lower Tertiary. The relative posi- 
tion of these different formations will be best conveyed by the 
the following diagram; merely premising that we are fully aware 
of the objections which have been urged against these divisions, 
and that we adopt them in the absence of a better nomencla- 
ture, as possessing a very convenient, and, we believe, a natural 
adaptation to the strata. 
Characteristic fossils. Localities. 
Alluvium 
Mouth of the Potomac. 
Peninsula of Maryland, and 
eastern parts of Virginia, 
N. and S. Carolina, Georg. 
Diluvium 
Bones of terrestrial ani- 
mals. 
Gravier coquillier, of 
Brong. Crag. 
Upper Marine, or 
Upper Tertiary 
Shells, all of existing 
species. 
Shells, chiefly bivalve, all 
the genera and many 
of the species existing. 
Middle Tertiary or 
London Clay, & 
Calcaire grossier 
Shells, nearly all living 
genera, but generally 
extinct species. Large 
proportion of univalv. 
Fort Washington, Md., Vir- 
ginia! Vance’s Ferry, S. C. 
Claiborne, Alabama. 
Bordentown, N.J., Martha’s 
Vineyard, &c. 
Lower Tertiary, or 
Plastic Clay. 
Beds of lignite and a few 
marine shells. 
B 
