[N] 2005 P/T extinction not a Big Bang
The P/T extinction that accured 250 million ago was the biggest mass extinction in Earth\\\\\\\'s geologic history ans id also called \\\\\\\"The Great Dying\\\\\\\" 90 percent of ocean species and 70 percent of land species went into extinction. Recent research indicates that global warming caused by massive and prolonged volcanic activity may have been the chief culprit. Open volcanic fissures known to geologists as the \\\\\\\"Siberian Traps,\\\\\\\" released huge amounts of carbon dioxide triggering a greenhouse effect that warmed the earth and depleted oxygen from the atmosphere, causing environmental deterioration and finally collapse.
This global awrming the oceans crippled there ability to refresh their oxygen supply, causing the seas to go sterile, destroying marine life and allowing anaerobic bacteria (which do not require oxygen) to release poisonous hydrogen sulfide \\\\\\\"swamp\\\\\\\" gas into the air. According to University of Washington paleontologist Peter D. Ward the great dying was not a big bang, his study shows a worl in trouble over a longer period of time. Ward led a team of scientists in a seven-year project to chronicle 126 fossil skulls in a 1,000-foot-thick deposit of sedimentary rock in southeastern South Africa\\\\\\\'s Karoo Basin.
The study also shows a steady decline in the number of species over 10 million years, followed by a sudden plunge 250 million years ago at the boundary between the Permian and Triassic periods of geologic time. The interval corresponds to a period of prolonged volcanic activity over one-third of modern-day Siberia. Temperatures climbed globally as carbon dioxide poured into the atmosphere and oxygen levels fell, forcing gasping animals to gather at sea level, he said. \\\\\\\"And the plants are not dealing well with the heat\\\\\\\" either, he added. \\\\\\\"Eventually the imbalance reaches a critical point, and everything dies.\\\\\\\"
As a result of the warming polar oceans were not cooled as much as they are today, and the convection cycle that circulates cold, oxygen- and nutrient-rich water between the poles and the tropics was slowed and even stopped, according to a team of researchers led by Kliti Grice of the Curtin University of Technology in Perth, Australia. Analyzing sulfur and carbon isotopes from core samples taken from the ocean bed off the coast of northwestern Australia, the team detected molecular traces from green sulfur bacteria, known as Chlorobiaceae, at the time of the Great Dying.