Permian period

Section 8.6.2, the Permian period ended with the largest mass extinction event that has yet occurred on planet Earth. As the ocean began a sustained recovery at the beginning of the Mesozoic era, opportunities likely abounded for the survivors to take over empty ecological niches through evolutionary adaptation. Prior to the advent of planktonic... 

Conway (1942) and Smulikowski (1954) have interpreted the potassium-distribution data to indicate that there is a potassium deficiency in Tertiary and Recent seas. However, Spiro and Gramberg (1964) made analyses of the composition of cations adsorbed on argillaceous rocks of northern Siberia and concluded that ... the highest content of potassium is inherent in marine water of the Permian Period. In Triassic seas the content of the potassium dropped significantly, and reached a minimum in seas of the Jurassic Period. Beginning with Cretaceous, the amount of potassium in sea water increased again, and during the Quaternary Period its level approached that of the Permian seas. These ideas are extremely speculative. 

Paleozoic Era The period of time beginning 570 million years ago ending 245 million years ago falls between the Proterozoic and Mesozoic Eras and is divided into the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian Periods. 

Permian Period The last geologic time period of the Paleozoic Era, noted for the greatest mass extinction in earth history, when nearly 96% of species died out. 

A survey has shown that the city of Enshi, Hubei Province, China, has three major Se-enriched deposition periods including the early Cambrian, Late Ordovician, and Permian periods. The stone coal formed during the first two periods has a low Se content of 30 pg g, which is similar to the stone coal formed in Early Paleozoic in Southern Shaanxi. However, the black shale series formed in the Permian period have a Se concentration that is at least threefold higher than that of the former two. There is a cross-cutting low-Se area with brown soil series from northeastern to the southwestern China including more than 10 provinces. Approximately 72% Chinese are deficient in Se, while there are about 1.5 billion people living in Se-deficient areas worldwide (Banuelos, 2009). 

About 250 million years ago, 90% of life on earth was destroyed in some sort of cataclysmic event. This event, which ended the Permian period and began the Triassic (the P-T boundary), is the most devastating mass extinction in the earth s history— far surpassing the catastrophe 65 million years ago that wiped out the dinosaurs (the K-T boundary). 

Even more surprising is the presence of the diunsaturated acid 18 2 in all coal samples studied. The presence of diunsaturated acids is indeed highly unusual because of their inherent instability under geological conditions. Itihara et al. (42) have reported the presence of 18 2 in a fossil walnut stone of estimated age one million years (Pleistocene), but this appears to be the first report of a diunsaturated acid in a sediment or coal from the Eocene epoch or the Permian period. 

Most deposits of coal were formed during the Carboniferous and Permian periods. More recent periods of coal formation occurred during the early Jurassic and Palaeogene periods. Coal deposits occur in all the major continents, and coal is used as a fuel and in the chemical industry by-products include coke and coal tar. Combustion of coal is a major source of greenhouse gases worldwide, and efforts are underway to develop clean coal technology. 

Palaeozoic The first era of Phanerozoic time. It follows the Precambrian and is subdivided into the Lower Palaeozoic, comprising the Cambrian, Ordovician, and Silurian periods, and the Upper Palaeozoic, comprising the Devonian, Carboniferous, and Permian periods. It extended from about 542 million years ago to about 251 million years ago, when it was succeeded by the Mesozoic era. 

The location of the Shackleton Range at the edge of the East Antarctic craton and between the Filchner Ice shelf and the East Antarctic Ice Sheet suggests that it should have been glaciated during the Permian Period as well as during the Plio/Pleistocene ice age. 

The coal-bearing Weller Formation is overlain by the Feather Conglomerate which is prominent at Mt. Feather (Fig. 10.2), but which also occurs on Mt. Fleming (Fig. 10.5) and on Portal Mountain located at the edge of the polar plateau. The Feather Conglomerate is 160 m thick, according to McKelvey et al. (1970), and was deposited by braided streams during the Permian Period (Barrett and Fitzpatrick 1985). 

The most plausible interpretation of the result of this calculation is that carbonate concretions in the Pagoda Tillite formed in contact with glacial meltwater of the continental ice sheets that covered a large area of Gondwana during the Permian Period. This... 

The water which formed the calcite cleats in the Permian coal deposits of southern Victoria Land is depleted in 0 almost as much as the water that formed the carbonate rocks in the Permian sandstones and shales in the central Transantarctic Mountains (Table 11.2). Therefore, the cleats may have formed during the Permian Period in glacial meltwater that was depleted in 0. Alternatively, the cleats could have formed much more recently from meltwater of the present-day snow adjacent to the Transantarctic Mountains which also has 5 0 values between -20%oand-30%o on the SMOW scale. The age of the calcite cleats in the Permian coal of the Transantarctic Mountains is presently unknown. 

The end of the Permian Period is defined by the extinction of about 90% of all life forms that existed on the Earth at that time. This catastrophe was even more severe than the extinction event that defines the end of the Cretaceous Period which resulted from the profound environmental disturbance caused by the impact of an asteroid at Chicxulub on the Yucatan Peninsula of Mexico. The cause of the Permo-Triassic extinction could have been a dramatic fluctuation of the global climate, or of sealevel, or the impact of an asteroid or comet, or severe volcanic activity, or all of the above. 

Lystrosaurus and most of the plants and animals that inhabited the Triassic forests of East Antarctica were the descendants of ancestors who survived the mass extinction at the end of the Permian Period. The cause of that catastrophe during which 90% of all life forms perished is still unknown. The best explanation is that the extinction resulted from the consequences of the impact of an asteroid which triggered large-scale volcanic eruptions at the antipode opposite the impact point. The volcanic eruptions that followed prolonged the disturbance of the global climate because the dust... 

Coal formation began during the Carboniferous Period (known as the first coal age), which spanned 360 to 290 million years before present. The Carboniferous Period is divided into two parts. The Lower Carboniferous, also called the Mississippian, began approximately 360 million years ago and ended 310 million years ago. The Upper Carboniferous, or Pennsylvanian, extended from about 310 to 290 million years ago, the beginning of the Permian Period. 

Ziegler, A.M., Gibbs, M.T., and Flulver, M.L. (1998) A mini-atlas of oceanic water masses in the Permian period. Proceedings of the Royal Society of Victoria, 110, 323-343. 

Fossils of organisms that are clearly mosses exist from the Palaeozoic, from the Carboniferous and Permian periods onwards (see Krassilov and Schuster, 1984 and Ooslendorp, 1987 for comprehensive discussion of these), but it is evident from our results that the majority of lineages of extant mosses originated in the Mesozoic, with considerable diversification occurring in the Cretaceous and in the Cenozoic (Figure 17.1). 

The causes for replacement of the paleophytic flora of the Pennsylvanian (Carboniferous) by the mesophytic flora of the Permian period are reasonably self-evident, because the cryptogam plants are inferior in reproductive capacity to the Gymnospermeae. The second replacement, which occurred in the Jurassic and Cretaceous periods, is less easily understood. Indeed, the Gymnospermeae have persisted up to the present time and are,... 

A series of tectonic collisions between the eastern margin of North America and other land masses during the Devonian and Carboniferous to Permian periods (approximately 400 and 300 million years ago, respectively) deformed the sequence of Silurian and Devonian rocks in the Rosendale region and uplifted the ancient Appalachian Mountains. Today, the deeply eroded western flank of the ancient Appalachian... 

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