64 
GEOLOGV 
porphyric eruptions have metamorphosed it into anthracite, and sometimes even into plumbago. In 
the State of Pennsylvania there is also a large tract of anthracite , in the neighbourhood of the erup- 
tive and metamorptiic rocks of the Blue Ridge of the Alleghany mountains. 
The thickness of the coal measures varies in different places; in Nova Scotia they are ten 
thousand feet thick, while in Iowa, Missouri, and Arkansas, they have only from two to three 
thousand feet of thickness. The fossil plants found in this formation are often of the same species 
as those found in the coal measures of Europe; the most characteristic ones are: Lepidodendron eU- 
gans ; Sigillaria Sillimanni- Neuropteris cordata , Seur. Losbii; Pecopteris lonchilka and Calamites cistii. 
The coal hasin of the gulf of S' Lawrence includes the shores of S' George’s bay, Newfound- 
land; nearly half the island of Cape Breton, and the whole coast from the straits of Canseau to 
Bathurst in the hay of Chaleurs. In the western part of Pennsylvania we find the immense coal 
hasin of the Alleghanies, which extends through eight States of the American Union, from Bloss- 
burg, Pennsylvania; to Tuscaloosa, Alabama. 
On looking at the geological map — see frontispiece — it will he seen that the large bituminous 
coal basin of the Alleghanies formerly joined those of Michigan, Illinois, Kentucky, Iowa, Missouri, 
Arkansas and Texas ; and that all these different basins formed originally but one , which may be 
called the great coal field of the Missi^ippi valley. 
The separation and division into several coal beds was effected by immense denudations that 
have carried away a part of the strata, and hollowed out the grand ravines in which are now (low- 
ing the Ohio, Illinois, Mississippi, des Moines, Missouri, Arkansas, Tennessee, Wabash and other 
rivers. These denudations took place at the moment of the dislocation of the Alleghanies, and 
have continued ever since until now. 
The peninsula of Michigan contains the most distant of these basins, it is also the smallest. 
The State of Illinois is entirely formed of a large coal basin that extends beyond the limits of the 
State and occupies a part of the States of Indiana and Kentucky. This basin, usually called the 
Jllinois coal field, is separated from the Iowa and Mississippi basin only by the valley of the Mis- 
sissippi. 
There is , finally , west of the Mississippi another immense coal basin extending without inter- 
ruption from a point above Fort des Moines, in Iowa, to Fort Belknap and the Rio Colorado in 
Texas. 
In the Rocky mountains this formation is seldom seen and the strata are of inconsiderable thick- 
ness. I found beds of bituminous coal between San Antonio and Manzana in New Mexico, and in 
the Sierra de Mogoyon near the headwaters of the Rio Colorado Chiquito ; and Captain Stansbury 
discovered coal belonging to the Carboniferous epoch, near Independence Rock on the road lead- 
ing from Fort Laramie to Fort Bridgers. The Mormons have also found it near their settlements 
Cedar and Parowan. 
The coal measures have been found between California and Oregon on the Pacific coast, near 
the Umpqua river, and also at Soke harbour in Vancouver island. 
New Red Sandstone formation. * The New Red Sandstone had been found only at some points on 
the Atlantic shore, from Prince Edward’s island to North Carolina. 
In the summer of 1848 I found it at Lake Superior, of which it forms the entire south shore. 
