Frasnian-Famennian Extinction

The Slate Belt bioregion is nested within the Great Valley Section of the Valley and Ridge Province that was formed by thrust and fault folding during the Late Ordovician period through and Late Paleozoic era.(Bailey,1992; Geyer, 1979;Van Diver, 1990). During this time Taconian

“A minority disputes this theory, arguing that other events-such as volcanic eruptions, sea-level changes or a series of impacts-were to blame for the spectacular loss of species that occurred at the transition between the Cretaceous and Tertiary periods…”

Large amounts of iridium – a chemical element that is not a part of the Earth’s crust composition – were originally found in rocks of Europe and United States, and have been found everywhere ever since. Iridium, common in meteorites, is a testable evidence of the disaster hypothesis. Gould continues that the Cretaceous debacle, which is one of five episodes of mass dying, occurred at the same time as the large comet might have smashed into the Earth. The author believes this is not merely a coincidence, rather, it is a proof of the cause-effect relationship. The demise of a wide range of habitats along with the extinction of dinosaurs gives an inestimable advantage to the disaster theory over other claims, the author adds. The comet struck the Earth, and habitats, from terrestrial to marine, died with geological suddenness. Finally, this hypothesis has had an impact on the study of an atomic war and its consequences. A nuclear war, Gould says, may cause a huge drop in temperatures and result in the extinction of humanity. Testable evidence, study, development, contribution – all this makes good science.

Gerta Keller, professor of geosciences at Princeton University, has recently conducted research on the Chicxulub asteroid in which she analyzed new core samples taken from the asteroid site (Botzer 2004). These samples indicate that the impact that occurred at Chicxulub actually predated the mass extinction of the dinosaurs, which occurred at the Cretaceous-Tertiary boundary about sixty-five million years ago. Keller claims that the Chicxulub impact occurred approximately 300,000 years before the extinction (Keller 2004). Although previous researchers estimated that the Chicxulub asteroid was the cause of the extinctions, there had always been doubts about the exact age and size of the crater, and about the origin of the “mega tsunami deposits” that were located within the crater (Keller 2004). The focus of Keller’s recent research was on finding some answers to these questions. To do so she analyzed Cretaceous limestone, dolomite, and anhydrite deposits as the site of the Chicxulub crater (Keller 2004).

The youngest of these rocks are dated at about 220,000 years ago. Rhyodacties and quartz latites in the modern caldera area extruded from about 320,000 years ago to 260,000 years ago, and then silica-rich rhyolites at Glass Mountain northeast of the caldera erupted from about 210,000 years ago to 80,000 years ago. The scattered distribution of the initial mafic eruptions indicates that they were erupted from the mantle, while the slightly younger domes and flows were from a deep-crustal source. The youngest rhyolite eruptions erupted at the northeast rim of the caldera at Glass Mountain and were the first activity of the silicic Long Valley magma chamber (Bailey, et. al., 1989).

Sims et al. (1989) synthesized U-Pb zircon ages for the Pembine-Wausau terrane. Sims concluded that the volcanic rocks were generated from around 1889 to 1860 Ma as island arcs and closed back-arc basins above the south-dipping subduction zone (Niagara fault zone). Granitoid rocks in the terrane, emplaced from around 1870 to 1760 Ma, are mainly granodiorite and tonalite but include gabbro, diorite, and granite. These developed as island arcs above the Eau Pleine shear zone. The Niagara fault zone contains a relict ophiolite, suggesting that the rocks in the Pembine-Wausau terrane probably accumulated on

8. The periods in which there were mass extinctions are Permian – volcanic eruptions which spewed lava and put CO2 into the air which warmed the climate an estimated 6 degrees Celsius. The resulting of oxygen deficiency. And Cretaceous – asteroid or comet

“The Great Dying” was the largest mass extinction ever recorder in the Earth’s history. It was the death of approximately 90% of all living species, such as, the trilobites, sea scorpions, and coral dating back to 254 million years ago (Randall). It is suspected that the eruption of many volcanoes in the Siberian Traps was the fallout of these species because the eruption killed off almost all plant life, leaving nothing for the animals alive. However, researchers have found new evidence to suggest that acid rain was the cause for this destruction (Randall).

Below these Carboniferous rocks, Devonian rocks are also exposed. These rocks can be found along the northern edge and southeastern margin of the plateau, where strata is nearly vertical. These two geologic systems have also been subdivided into numerous formations categorized according to their lithologic aspect and the fossil fauna and flora which they

In order to find evidence of the transition from fish to land animals, the author and his colleagues chose to focus on 375 million year old rocks. In 2004, they studied sedimentary rock on Ellesmere Island in Canada’s Arctic as they thought that the rocks there would be exposed and untouched by humans, which would be ideal for fossil excavations. They studied sedimentary rocks (limestone, sandstone, siltstone and shales) because these

A period of volcanism resulted in igneous intrusions within the Raton Basin-Sierra Grande Uplift Province that was sourced from the upper mantle about 26. 6 billion years ago and is associated with parallel dikes and sills (Higley, 2007). Igneous rocks are common within the Raton Basin and include Tertiary dikes and sills that range in age from 6.7 to 29 5 million years ago (Flores and Bader, 1999). One of the main differences between dikes and sills is that dikes are longer lived magma conduits and sills are features that form when magma is in neutral buoyancy with the surrounding rock (Rooper et al., 2006). These volcanic events are associated with hydrothermal alteration of coal within the basin (Higley, 2007).

Assess the different hypotheses put forward for the mass extinctions at the end of the Permian and Cretaceous (KT) Periods.

Just the fact that the Pope has ignored the warnings of Catholic presidential candidates and is trying to fight climate change is monumental. Global warming is a global issue. No matter what religion or ethnicity global warming will affect everyone. Earth is the only known planet capable of supporting life. How embarrassing will it be for our generation if we wipe out life because of our ignorance. Earth has a marvelous ability to rebuild and return to a healthy state. After each of the five mass extinction events Earth was resilient enough to survive and so did life. After the most notorious, the Permian Mass Extinction, less than 4% of life survived. Miraculously Earth rebuilt its ecosystems and was able to sustain life. The causes of the

The Smilodon, commonly known as the Saber-toothed Tiger, was an intense carnivore in which was completely unrelated to today’s common Asian Tiger. Saber-toothed cats are predicted to have gone extinct towards the end of the Pleistocene era, 12,000 years ago. The exact cause of the extinction is unknown, however, scientists believe it to be due to the extinction of animals they preyed on, with the possibility of climate change. Smilodons lived in North and South America, generically in grasslands, shrubby areas, and pine forests that also supported the plant-eating lifestyle of animals that Saber-tooths so frequently preyed on. The fossils of this particular species was first discovered in 1842, in Brazil. Currently, the largest known collection

By testing sediment and recording whether it was deposited under conditions of normal polarity and then measuring successive layers, we can build a time chart. By matching different charts from different areas with similar fossils, a more global correlation can be made.