Orogenic movements in the Appalachians had probably begun in the middle Carboniferous, as was seen in the folding which inaugurated the Pottsville trough, and toward the end of the Carboniferous there was in the low-lying Appalachian coal-field a slowly progressive movement of elevation, resulting in the draining and drying up of most of the region over which the peat-bogs had been extended. The movement spread east, north, and south, leaving in the middle of the region a smaller area in which the conditions of the coal measures continued very much as before. In the northern part of the Acadian province Permian beds overlie the coal measures in Prince Edward Island, Nova Scotia, and New Brunswick. These beds are soft red shales and sandstones, which were laid down in closed basins, not in the sea. In Pennsylvania, Ohio, West Virginia, and Maryland, the Permian beds follow directly and without any break upon the Monongahela stage of the coal measures: they were formerly called the Upper Barren Measures, and consist of 1000 feet of sandstones and shales with some limestone and a few seams of coal.

The character of these beds is entirely like that of the coal measures, to which they were once referred, and their reference to the Permian is due to the marked change which had come over the vegetation. South of West Virginia .10 Permian beds have been found in the Appalachian area, owing to the elevation of this part of the region at the close of the Carboniferous, but the Permian occurs in Illinois, in what appears to be a stream-channel cut in the coal measures.

As we proceed westward and southward through Missouri into Nebraska, Kansas, and Texas, we find the Permian assuming much greater importance, and becoming more and more prominently developed in extent and thickness. A study of this region reveals the fact that only a part - the lower - of the Permian is developed in the Acadian and Appalachian areas. At the end of the Lower Permian the' entire series of the coal measures east of the Mississippi River was elevated and the deposition of strata apparently ended, though there is no way of determining exactly when this elevation took place, nor how great a thickness of beds has been removed by denudation since the upheaval. In the region beyond the Mississippi the Permian beds thicken southward, attaining in southern Kansas a thickness of 2000 feet, and in Texas of more than 5000 feet. The mountains of Oklahoma, which may have been raised late in the Carboniferous or early in the Permian, separate the Texas and Kansas areas.

During the greater part of the Permian period the geographical state of North America was somewhat as follows. Except for the coastal plain on the Atlantic and Gulf of Mexico, the eastern portion of the continent had very much its present limits, though the position of the eastern and southern coasts cannot be determined. The coastal plain is deeply buried under deposits which are much younger than the Permian, and the continent may have extended farther into the Atlantic than at present, or the ocean may have extended more over the land. The Interior Sea was greatly changed both in extent and character from what it had been in the Upper Carboniferous, as is shown by the nature and distribution of its sediments. From most of the Mississippi valley the sea had withdrawn entirely, but still extended, as shallow and shifting waters, into southeastern Nebraska and Kansas, possibly into Iowa, and from eastern Kansas the line ran westward and southwestward across Oklahoma far into Texas. In the latter part of the period, lagoons were cut off from the sea and converted into salt and bitter lakes in which the salt and gypsum of Kansas and the gypsum of Oklahoma and Texas were precipitated.

Occasionally the sea broke into these lakes, bringing a marine fauna with it for a short time.

The Wichita beds of Texas have two very distinct facies; in the north they are made up chiefly of fine red clays, with some beds of sandstone, conglomerate and impure limestone. The clays are principally river deposits made in a delta, or along a very flat coast, but with marine conditions at intervals. Passing southward, these beds gradually merge into marine limestones which were originally named the Albany stage and placed at the top of the Coal Measures. The succeeding Clear Fork beds, which are chiefly clays like those of the Wichita, but cut by many channels filled with cross-bedded sandstones, extend southward over the marine limestones of the Albany facies, but even in the north thin layers of limestone containing marine fossils are indicative of transgressions of the southern sea. The Double Mountain beds are largely the deposits of a salt lake and contain much gypsum, without any marine fossils, though in Oklahoma beds of a corresponding horizon have a scanty fauna between and above the gypsum layers.

Westward from Texas, the inland Permian sea extended over northern Arizona into southern Utah, where the beds are sandy shales, with much gypsum. The sea continued northward through eastern Utah, western Colorado, and probably east of the Rocky Mountains also, to the Black Hills and central Wyoming, forming an island in central Colorado. This immense body of water, or perhaps series of smaller bodies, was land-locked and salt, and in it were formed the characteristic " Red Beds " so widely distributed over the region mentioned, pointing to an arid climate. The Red Beds are not all Permian, however, and the rarity of fossils in them makes it often impossible to decide whether a given area of these beds should be referred to the Permian, to the subsequent Triassic, or to both. In southern Wyoming thin bands of sandstone and limestone in the Red Beds carry fossils very like those of the Kansas and Nebraska Permian, but the course of this marine invasion cannot yet be made out. Whether the Permian has been removed from the Great Basin by denudation, or never deposited over the greater part of it, is uncertain; but when this is determined, it will give the date of the upheaval of a land much of which had been submerged throughout the Palaeozoic era.

Another and altogether different facies of the North American Permian is the purely marine development found in the mountains of western Texas and on the Pacific coast, especially in Alaska, where more than 6000 feet of marine Permian have been found in the region of the Copper River. The Pacific coast fossils differ strongly from those of the more eastern regions, and the fauna of western Texas shows affinity with the Mediterranean and Indian.