OF SOUTH CAROLINA. 43 
OLDER PAL®OZOIC PERIOD. 
New York System. { 
: Systems, Formations, and | Localities of characterlstic | European Equivalents and 
8 
3 Groups. deposits in America. Localities. } 
: Upper Silurian Rocks. } 
; Chemung Group. i 
» Genesee Slate. New York and West- | Wales. 
* Marcellus Slate. ern States. ; 
* Ludlow and Wenlock | Alabama. Russia. ; 
Series. : 
_ Hilderberg Series. 
Lower Silurian Rocks. } 
Caradoc Sandstone. 
Llandeilo Flags. Vermont. Wales. 
Champlain Division. | New York. Scandinavia. 
¢ 
PaLzozoic SERIES. 
Pursuing the ascending order which has been adopted in this outline, we have next to take a 
rapid glance at the succession of the fossiliferous strata, beginning with the Paleozoic Series, 
which consists of the Silurian System, the Devonian, or Old Red Sandstone System, the Carboni- 
ferous System, and the Magnesian Limestone, or Permian System. 
Lower Silurian Strata—The term Silurian, (from Stlwres, the name of the ancient Britons, 
who inhabited Wales, where these rocks are extensively developed,) was first applied by Mr. 
Murchison, to designate the oldest of the fossiliferous rocks. Local names are useful, because they 
point to localities that can always be examined when any doubt arises as to the meaning of the 
author; for such names are taken from places where the rocks to which the names are applied 
oceur in their most characteristic form. Hence, in England, the names Caradoc sandstone and 
Llandeilo flags, and in this country, Trenton limestone, Potsdam sandstone, &c. applied to the 
Lower Paleozoic rocks. 
The Lower Silurian rocks, for the most part, consist of sandstones, conglomerates, impure lime- 
stones, and shales. Argillaceous and silicious matter is far more abundant than in the newer 
rocks, and the presence of mica proves that they owe their origin to the disintegration and abrasion 
of the granitic or the metamorphic rocks. 
In New York, where these rocks are finely developed, and where they have been studied with 
great care, they are known under the names of Potsdam sandstone, Birdseye limestone, Trenton 
Limestone, Utica slate, Hudson River group, &c. The principal of these formations extend along 
the Alleghanies, from New York to Alabama. Commencing at Vermont, they appear at intervals 
on the shores of the lakes, to the Mississippi River; and they are also found both in Ohio and 
Tennessee, ‘They are seen again in the Southern part of South America. In England, as well as 
on the Continent, these strata are widely spread. They are well known in Germany, and have 
been traced over a considerable extent in Russia, by Mr. Murchison. They occur in Norway and 
Sweden of vast thickness, and in Southern Africa they have also been recognized. ‘= 
In America the oldest of the Silurian rocks are represented by the Potsdam sandstone of the 
@, 
