OF NORTH AMERICA. 
65 
and I agree entirely with my friend Dr. Charles T. Jackson upon the age of the Red Sandstone 
of Lake Superior. Afterwards, in 1853 and 1854, 1 found the New Red covering an immense ex- 
tent of the Central region of the United States, in the Prairies and the Rocky mountains. The 
rocks composing this formation are especially red sandstone; red, green, yellow, and white sandy 
clay; amorphic and cristallized gypsum; dolomite or Magnesian limestone; and saliferous clay. In 
short, the rocks iii the New World are the same with those composing the Trias and Permian of 
Germany and France, and often, in crossing the Prairies , the illusion was so strong, that I thought 
myself transported to the valley of the Ncckar near Tubingen, or to the valleys of Argovie and 
the Canton of Rasel. 
In the gulf of St Lawrence the New Red Sandstone occupies a part of the northern coast of 
the bay of Chaleurs, the whole of Prince Edward’s island, and the Magdalen islands. It extends 
along the coast of the hay of Fundy and Minas Easin , and continues as far as below the town of 
Lubec in the State of Maine. The celebrated red sandstone of the Connecticut valley, containing 
footprints , raindrops , and fish , belongs to the New Red Sandstone , as well as the Red Sandstone 
found in narrow well defined basins scattered through the States of New Jersey, Maryland, Vir- 
ginia, and North Carolina. — In the environs of Richmond, Virginia, and in North Carolina, the 
upper part of this formation (Keiiper) contains a strata of bituminous coal, forty five feet thick; 
this is the largest coal seam known. 
In the West the New Red Sandstone formation begins near the Sault St Marie at the entrance 
to Lake Superior, surrounds this lake, passes by the headwaters of the Mississippi and the north- 
ern Red River, forms the plateau da Coleau du Missouri, extends into the western Prairies, and 
finally forms the basis of the high plains surrounding the Rocky mountains. It is found in the 
valley of the Rio Pecos, of the Rio del Norte in New Mexico, near Zuni, and in the country of 
the Navajo and Moqui Indians, on the Rio Colorado Chiquito and on the Rio Colorado Grande of 
California. I did not find it farther west than the 111° of longitude west from Greenwich. The 
red color of the rocks of this formation gives to the whole Central region a reddish appearance, 
and the rivers flowing through this Territory hear the names: Rio Colorado, Red River, Riviere 
Rouge, Riviere Vermillion, Rio Puerco, etc. 
Jurassic formation. - The existence of this formation in North America was long doubted. In 
1843 the brothers Rogers thought the Secondary coal field of the environs of Richmond , in Vir- 
ginia, belonged to the age of the Lias or Oolite; but without very valid reasons; in 1854 I 
assigned this coal field to the New Red Sandstone, which is its true position in the Geological 
Series. In 1853 I found in the Rocky Mountain region, rocks belonging to the Jurassic epoch; 
this discovery is supported and demonstrated in Chapter /, page 17, 18, and 19 of the present 
volume; hut previously, in the year 1847, the naturalist Ilia Wosnesseusky brought from Russian 
America fossils, that were recognized by Dr. C. Grewingk as belonging to the Jurassic epoch. 
The rocks of the American Jurassic consist chiefly of white and yellow sandstone, blue marl, 
and thin strata of oolitic or compact limestone of a white color. Fossils are rare and almost con- 
fined to the blue marl, where a variety of Gryphwa dilatata, which I have called var. Tucumcarii, 
and the Ostrea Marshii are very abundant. 
The geographical distribution of this formation is limited to the Central region of the United 
