The Permian limestones and marls occupy a strip in E.
Both to the east and to the west of this depression the Archean and Palaeozoic rocks which form the greater part of the island are strongly folded, with the exception of the uppermost beds, which belong to the Permian system.
At Bajo de Velis, in San Luis, the plants belong to the " Glossopteris flora," which is so widely spread in South Africa, India and Australia, and the beds are correlated with the Karharbari series of India (Permian or Permo-Carboniferous).
The Permian deposits are best developed in New South Wales and Tasmania, where their characters show the continuation of the Carboniferous conditions.
The Permian may be represented, but the Trias is absent, and in general the older Palaeozoic rocks are overlaid directly by the Rhaetic and Lias.
The latter is, no doubt, identical with the similar sandstone series which is found in the neighbouring Brazilian province of Rio Grande do Sul, and which has there yielded plants which prove it to belong to the Permian or the upper part of the Carboniferous.
Russia and in the Upper Carboniferous and Permian periods it was confined to the E.
By thick Permian and Triassic strata.
Russia, rich in salt-springs, but very poor in fossils, are now held by most Russian geologists to be Triassic. The Permian deposits contain marine shells and also remains of plants similar to those of England and Germany.
Some of the deposits appear to be of Permian age, but others are probably Jurassic; and they are all included under the general name of the Angara series.
East of Bolsover, the Coal Measures are covered uncomformably by the Permian breccias and magnesian limestone.
East of Bolsover, the Coal Measures are covered unconformably by the Permian breccias and magnesian limestone.
To the Permian period belongs a remarkable genus Eugereon, that combines hemipteroid jaws with orthopteroid wing-neuration.
This order can be traced with certainty back to the early Jurassic epoch, while the Permian fossil Eugereon, and the living order - specially modified in many respects - of the Thysanoptera indicate steps by which the aberrant suctorial and piercing mouth of the Hemiptera may have been developed from the biting mouth of primitive Isopteroids, by the elongation of some parts and the suppression of others.
The principal folding took place at the close of the Carboniferous period, and was contemporaneous with that of the old Hercynian chain of Belgium, &c. The Permian and later beds lie unconformably upon the denuded folds, and in the space between the Montagne Noire and the Cevennes proper the folded belt is buried beneath the horizontal Jurassic strata of the Causses.
The Trilobites are known only as fossils, mostly Silurian and prae-Silurian; a few are found in Carboniferous and Permian strata.
The beds are homotaxial with the Karharbari series of India, and represent either the top of the Carboniferous or the base of the Permian of Europe.
In the outer portion of the zone the Permian and Mesozoic beds are crushed and folded against the core of ancient rocks; in the inner portion of the zone they rest upon the old foundation with but little subsequent disturbance.
In the eastern Carpathians also, the Permian and Mesozoic beds are not much folded except near the outer margin of the zone.
Eugereon is a remarkable Permian fossil, with jaws that are typically hemipterous except that the second maxillae are not fused and with cockroach-like wings.
The uppermost portion of the Coal Measures consists of red sandstone so closely resembling that of the Permian group, which are next in geological sequence, that it is often difficult to decide upon the true line of demarcation between the two formations.
The actual coal measure strata, consisting mainly of shales and clays, are generally impervious to water, but when strata of a permeable character are sunk through, such as the magnesian limestone of the north of England, the Permian sandstones of the central counties, or the chalk and greensand in the north of France and Westphalia, special methods are required in order to pass the water-bearing beds, and to protect the shaft and workings from the influx of water subsequently.
Fossils of both vertebrates and invertebrates are also common in the Permian and Jurassic formations.
The eastern part of the Prairie Plains is a belt known as the Black Prairie, and it has a rich black soil derived from Upper Cretaceous limestone; immediately west of this is another belt with a thinner soil derived from Lower Cretaceous rocks; a southern part of the same plains has a soil derived from granite; in a large area in the north-west the plains have a reddish clay soil derived from Permian rocks and a variety of soils - good black soils and inferior sandy and clay soils - derived from Carboniferous rocks.
But Professor Park has obtained Jurassic fossils in the Maitai series; so that it will probably be ultimately divided between the Carboniferous and Jurassic. The two systems should, however, be separable by an unconformity, unless the Maitai series also includes representatives of the Kaihiku series (the New Zealand Permian), and of the Wairoa series, which is Triassic.
The Paleozoic sediments, ranging in age from Cambrian to Permian, occupy the Great Valley, the Valley Ridges and the plateaus still farther west.
Carboniferous and Permian strata are possibly represented by some black and grey micaceous shales with beds of coal in the Jurjura.
Similarly, the Mesozoic reptiles have been traced successively to various parts of the world from France, Germany, England, to North America and South America, to Australia and New Zealand and to northern Russia, from Cretaceous times back into the Permian, and by latest reports into the Carboniferous.
Cephalopod molluscs have been traced back to the straight-shelled nautiloids of the genus Volborthella, while true ammonites have been found in the inferior Permian of the Continent and by American palaeontologists in the true coal measures.
Thus the analysis of George Baur of the ancestral form of the lizards, mosasaurs, dinosaurs, crocodiles and phytosaurs led both to the generalized Palaeohatteria of the Permian and indirectly to the surviving Tuatera lizard of New Zealand.
Trend to crustal deformations which in very early geological time gave a beginning to what later came to be the Appalachian mountain system; but this system had Its climax of deformation so long ago (probably in Permian time) that it has since then been very generally reduced to moderate or low relief, and owes its present altitude either to renewed elevations along the earlier lines or to the survival of the most resistant rocks as residual mountains.
Another consequence of revived erosion is seen in the occurrence of great landslides, where the removal of weak (Permian) clays has sapped the face of the Vermilion Cliffs (Triassic sandstone), so that huge slices of the cliff face have slid down and forward a mile or two, all shattered into a confused tumult of forms for a score or more of miles along the cliff base.
Permian Period.The Permian system appears in smaller areas in the United States than any other Palaeozoic system.
The Upper Barren Coal Measures of some parts of the east (Ohio, Pennsylvania, &c.) are now classed as Permian on the basis of their fossil plants.
They represent but a part of the Permian period, and are commonly described under the name of the Dunkard series.
Some of the Permian beds of this region are marine, while others are of terrestrial origin.
In this part of the country the Permian beds are largely red sandstone, often saliferous and gypsiferous.
West of the Rocky Mountainf the Permian has not been very generally separated from overlying and underlying formations, though it has been differentiated in a few places, as in south-western Colorado and in some parts of Arizona.
Salt and gypsum deposits, and other features of the Permian beds, together with the fewness of fossils, indicate that the climate of the Permian was notably arid in many regions.
In the western plains and in the western mountains the Triassic is not clearly separated from the Permian in most places.
The climate of the period, at least in its earlier part, seems to have been arid like that of the Permian, as indicated both by the paucity of fossils and by the character of the sediments.
The close of the period, too, saw the exclusion of the sea from the Pacific coast east of the Sierras, and the disappearance, so far as the United States is concerned, of the great north-western bay of the late Jurassic. Before the close of the period, the aridity which had obtained during the Permian, and at least a part of the Triassic, seems to have disappeared.
Timor consists of a core of ancient rocks (Archean?) upon which rest Permian and later deposits of sedimentary origin.
Volcanic rocks are also present but they are not so extensively developed as in the islands of the Javan arc. The Permian beds consist chiefly of limestone and contain numerous fossils similar to those of the middle and upper divisions of the Productus limestone of northern India and the Artinsk stage of the Urals.
The age of a great part of the Palaeozoic belts is somewhat uncertain, but Permian, Carboniferous, Devonian and Silurian fossils have been found in various parts of the chain, and it is not unlikely that even the Cambrian may be represented.
Triassic Permian Plutonic Rocks Volcanic Rocks West of a line which runs from Lake Constance to Lago Maggiore the zones already described do not continue with the same simplicity.
He was distinguished for his researches on the Carboniferous and Cretaceous rocks and fossils of Saxony, and in particular for those relating to the fauna and flora of the Permian or Dyas formation.
CARBONIFEROUS SYSTEM, in geology, the whole of the great series of stratified rocks and associated volcanic rocks which occur above the Devonian or Old Red Sandstone and below the Permian or Triassic systems, belonging to the Carboniferous period.
Again, at the summit of the Carboniferous series, both the rocks and their fossil contents merge gradually into those of the succeeding Permian system, as in Russia, Bohemia, the Saar region and Texas.
This has led certain geologists to classify the Devonian, Carboniferous and Permian into one grand system; E.
In the eastern border of the Rhenish Schiefergebirge the Permian rests unconformably upon Lower Carboniferous rocks.
The folding of the Ural mountains began in the earlier part of this period and was continued, after its close, into the Permian; and there are traces of uplifts in central Asia and Armenia.
No Permian beds are known, and for many years Mesozoic deposits were supposed to be entirely absent, but Triassic clays and sandstones with Daonella have been found in the upper part of the basin of the Kwalu (East Sumatra).
The hills and plateaus appear to be composed chiefly of the same sandstone series which in the Brazilian province of Rio Grande do Sul contains seams of coal, with plant remains similar to those of the Karharbari series of India (Permian or Upper Carboniferous).
The Permian, as in England, is not involved in the folds which have affected the older beds, and in general lies unconformably upon them.
Durham is regarded by some authorities as Permian, but that near Carrickfergus ir.
The Permian system (Zechstein) yields the great salt-deposits worked at Stassfurt and at Halle in Prussian Saxony.
1.2.1 Archean Rocks 1.2.2 Eastern or Younger Schists 1.2.3 Torridonian Sandstone 1.2.4 Cambrian 1.2.5 Ordovician and Silurian 1.2.6 Old Red Sandstone 1.2.7 Carboniferous 1.2.8 Permian 1.2.9 Triassic 1.2.10 Jurassic 1.2.11 Cretaceous 1.2.12 Older Tertiary 1.2.13 Post-Tertiary 1.2.14 Recent
Rocks assignable to the Permian system occupy only a few small areas in Scotland.
Another isolated patch occurs among the Lead Hills; and lastly, a considerable space in the heart of the Ayrshire coal-field is occupied by Permian rocks.
There can be no doubt that the valleys in which these patches of red rocks lie already existed in Permian time.