The name Permian was given by Sir Roderick Murchison in 1841 to a series of rocks which is very extensively developed in the province of Perm in Russia. In North America the Permian followed upon the Carboniferous with hardly a break, so that the distinction between the two systems must be made entirely upon the fossils, which change very gradually, by drawing a somewhat arbitrary line of demarcation. In various countries there is no general agreement regarding the upper boundary of the Carboniferous, and there are very great differences of opinion as to the correlation of the rocks of different continents, due chiefly to the want of an unbroken succession of fossils in any single area. The regions where the Permian beds are best known, Germany, England, and Russia, are not those which yield the normal facies of marine life, and hence any correlation with the latter is full of difficulties, and in the following table of the American Permian, no comparison is attempted with that of other countries.

In consequence of these uncertainties, many geologists, especially in this country and in France, regard the Permian as a mere subdivision of the Carboniferous. Its relations with the overlying Triassic system are, however, nearly as close, and by some authorities it has been referred to the latter. The Permian is, on the whole, distinctively Palaeozoic, but it has several features which mark it out as transitional to the Mesozoic.

Permian System