Permian-Triassic Boundary
Summaries
Synchrony and Casual Relations Between Permian-Triassic Boundary Crises and Siberian Flood Volcanism" by Paul R. Renne, Zhang Zichao, Mark A. Richards, Michael T. Black, Ashish R. Basu
The paper focuses on the mass extinction that took place at the Permian-Triassic (P-T) boundary, as the greatest bio-crisis on Earth, whereby almost 90% of the marine species and 70% of terrestrial species were eliminated. This paper regards the Siberian traps, the most significant "continental flood volcanism," and this is perceived as the primary cause of the crisis. The paper investigates the Siberian traps inception age and compares it to the P-T boundary age of the Shangsi and the Meishan sections through critical value tests. The test determines …show more content…
that the Siberian volcanism could have begun as long as 5 to 2.6 million years ago. Following the comparison of the ages, the paper evaluates the step-heating plateau date, which is an analysis of the incremental heating which indicates a younger age, and differentiates by 0.02 ± 0.36 million years. Nonetheless, the paper states that there is a low probability of age difference between the events and thus, would support the causal relation between the two. The paper argues the possibility of a volcanic flood, that leads to a marine regression, due to the amount of Sulphate produced and therefore ice, which created a massive winter with greenhouse conditions causing the mass P-T extinctions. Experts still believe that there could be a culmination of events leading to this (Renne et al. 1413-1416).
"Oceanic Anoxia and the End-Permian Mass Extinction" by Paul B. Wignall and Richard J. Twitchett.
The primary attention of this paper is laid on how the oceanic anoxia took place in shallower waters and that the high-latitudes in the Boreal sections were also affected by the occurrence.
Experts of the mass extinction that took place at the end of the Permian suggest that the timing and causes of the happening are yet to be found as well as the fact that the Siberian traps would be linked with this event. The investigation carried out looked at the sedimentological and ichnology study of the P-T boundary in Spitsbergen that happens are situated in the Boreal Ocean margins and a study of the geochemical analysis in the western Tethys equatorial sections, specifically in the shallow waters. Three locations where evaluated: Kapp Starostin, Kapp Wijk and Sveltihel, which had very similar facies development. The data found, showed that the anoxic conditions affected the Boreal Ocean in the same time period as the P-T crisis. Evidence showed that the Mazzin sea was between anoxic and dysoxic and in the peritidal fringing was oxygenated. Finally, sedimentological and paleobotanical findings demonstrated the presence of warming and "cold-loving plants" however temperatures in oceanic waters rarely cause extinction, as temperatures have to be as high as 30°C. Although, what could have happened was an increase in oxygen intake as temperatures rose, which is an issue in oxygen-deficient waters which was the case (Wignall and Twitchett …show more content…
1155-1158).
"End-Permian catastrophe by bolide impact: Evidence of a gigantic release of sulfur from the mantle" by Kunio Kaiho, Yoschimichi Kajiwara, Takanori Nakano, Yasunori Miura, Hodaka Kawahata, Kazu Tazaki, Masto Ueshima, Zhongqiang Chen, Guang R. Shi.
The basis of the paper was the End-Permian crisis and studied the geochemical and paleontological samples from the Meishan section. Whilst evaluating the samples, there was suggestions that the mass extinction occurred simultaneously with an increase in Ni the same was found in the Cretaceous-Tertiary (K-T) boundary. In the ocean asteroidal or cometary accompanied the extinction as helium and argon were encountered in the sediments. And Fe-Si-Ni grains were found, as Fe and Ni separated and mixed with Si or Al within the oceanic crust and mantle suggesting an impact. The oceanic impact showed that approximately 99% of the Sulphur came from the mantle and thus, this could have created volcanism, and the paper states an example of the Siberian flood, as the Sulphur is usually "supplied from impact-induced volcanism." The chemical reactions 1 and 2 implied in the paper show that there was consumption of oxygen which decreased atmospheric oxygen and was dissolved in the ocean; as well as the chemical reactions show an increase in hydrogen at the time period causing acid rain. In conclusion, the increase in Ni layer, caused Sulphur to be released by the mantle, and together with the oxygen consumption and acid rain caused the mass extinction (Kaiho et al. 815-818).
Critique: Most likely cause of the P-T Mass extinction
The Permian-Triassic (P-T) mass extinction, is until today considered the most severe mass extinctions, out of approximately five major extinction occurrences in Earth's history. The duration of this mass extinction is until today one of the most debated aspects of the mass extinction. Some experts such as geologists and paleontologists believe it could have been a rapid process of about 200,000 years; however, others believe that it was a longer process, approximating 15 million years ("Permian Extinction"). Nonetheless, it is a fact that around 90% of the marine species were eradicated, and 70% of terrestrial species were eliminated (Renne et al. 1413-1416). According to some experts, only 4% of Earth's species survived. Although the timeframe is a debating aspect, the most discussed factor of the event is still the causes. There are a number of possible causes, and many of which have been studied, encompassing the flood basalt eruptions, changes drop in oxygen levels, changes in temperature, ocean level, changes in the carbon cycle, and many times, a combination of all these possible causes ("BBC Nature - Permian Mass Extinction Videos, News, And Facts").
One of the possible causes is changes in temperature or a crisis in temperature. This might have played a big role in the cause of the mass extinction. The greatest cause is the evidence found at high temperatures. The issue with high temperatures is that it affected the nutrients available to the species at the time. As well as many marine species were unable to live in overly high temperate waters, especially in the shallow waters. As Wignall and Twitchett discussed, there was evidence of "warming and cold loving-plants". Nonetheless, they argue that high temperatures would not eradicate any species unless temperatures reached a of high 30°C and evidence shows that the temperatures only rounded 25-27°C (Wignall and Twitchett 1155-1158). This was only in shallow waters, a lot of marine species are found in deeper waters, and these would not be as affected, as the photosynthetic process were uninterrupted. Ultimately, the temperature could have played a role in some aspects, but not completely on its own.
A second cause could have been changed in the carbon cycle, this discusses, the ocean anoxia, which is related to the Siberian Traps, which is discussed by Renne et al., where stated that the volcanic flood, lead to a potential marine regression, and that through this, there was a large amount of Sulphate which then lead to the creating of ice, and due to this, a large change in carbon dioxide in the environment. This is also related to the greenhouse conditions in the atmosphere. However, this then affects the ocean, and Kaiho et al., discuss that through the change in the conditions in the atmosphere, there was an increase of oxygen consumed in the oceanic waters. Creating oxygen to dissolve in the ocean, and this increase they hydrogen levels creating acidic rain. This is to show that causes are interlinked. Renne et al. discuss one this, however, this can be linked to what is studied by Kaiho et al. Without combining the two studies, it would be hard to say that the marine regression was the only cause, or that the changes in oxygenation and they would contradict each other without being put together.
Nonetheless, there are other causes that are not related to any of the above stated.
One that is considered a hot topic is the movement of the continental plates. This is the movement of the north-south plates moving towards each other, causing an alteration in ocean currents and a change in climates. If this was the case, it would contradict any other potential causes because this would eliminate any changes in the carbon cycle, oxygenation; however, temperatures could potentially have changed. The only issue with the continental plate movement is that the Pangea was already in place before the estimated time of the mass extinction occurrence ("Permian Extinction"). To conclude, a better way to look at the mass extinction and what caused it, is definitely a combination of all aspects, leading to the extinction of the species. It can be looked at as a massive
puzzle.
Word Count: 1, 319
References:
"BBC Nature - Permian Mass Extinction Videos, News And Facts". Bbc.co.uk. N.p., 2016. Web. 2 May 2016.
Kaiho, Kunio et al. "End-Permian Catastrophe By A Bolide Impact: Evidence Of A Gigantic Release Of Sulfur From The Mantle". Geol 29.9 (2001): 815. Web.
"Permian Extinction". Encyclopedia Britannica. N.p., 2015. Web. 2 May 2016.
Renne, P. R. et al. "Synchrony And Causal Relations Between Permian-Triassic Boundary Crises And Siberian Flood Volcanism". Science 269.5229 (1995): 1413-1416. Web.
Wignall, P. B. and R. J. Twitchett. "Oceanic Anoxia And The End Permian Mass Extinction". Science272.5265 (1996): 1155-1158. Web.
Synchrony and Casual Relations Between Permian-Triassic Boundary Crises and Siberian Flood Volcanism" by Paul R. Renne, Zhang Zichao, Mark A. Richards, Michael T. Black, Ashish R. Basu
The paper focuses on the mass extinction that took place at the Permian-Triassic (P-T) boundary, as the greatest bio-crisis on Earth, whereby almost 90% of the marine species and 70% of terrestrial species were eliminated. This paper regards the Siberian traps, the most significant "continental flood volcanism," and this is perceived as the primary cause of the crisis. The paper investigates the Siberian traps inception age and compares it to the P-T boundary age of the Shangsi and the Meishan sections through critical value tests. The test determines …show more content…
that the Siberian volcanism could have begun as long as 5 to 2.6 million years ago. Following the comparison of the ages, the paper evaluates the step-heating plateau date, which is an analysis of the incremental heating which indicates a younger age, and differentiates by 0.02 ± 0.36 million years. Nonetheless, the paper states that there is a low probability of age difference between the events and thus, would support the causal relation between the two. The paper argues the possibility of a volcanic flood, that leads to a marine regression, due to the amount of Sulphate produced and therefore ice, which created a massive winter with greenhouse conditions causing the mass P-T extinctions. Experts still believe that there could be a culmination of events leading to this (Renne et al. 1413-1416).
"Oceanic Anoxia and the End-Permian Mass Extinction" by Paul B. Wignall and Richard J. Twitchett.
The primary attention of this paper is laid on how the oceanic anoxia took place in shallower waters and that the high-latitudes in the Boreal sections were also affected by the occurrence.
Experts of the mass extinction that took place at the end of the Permian suggest that the timing and causes of the happening are yet to be found as well as the fact that the Siberian traps would be linked with this event. The investigation carried out looked at the sedimentological and ichnology study of the P-T boundary in Spitsbergen that happens are situated in the Boreal Ocean margins and a study of the geochemical analysis in the western Tethys equatorial sections, specifically in the shallow waters. Three locations where evaluated: Kapp Starostin, Kapp Wijk and Sveltihel, which had very similar facies development. The data found, showed that the anoxic conditions affected the Boreal Ocean in the same time period as the P-T crisis. Evidence showed that the Mazzin sea was between anoxic and dysoxic and in the peritidal fringing was oxygenated. Finally, sedimentological and paleobotanical findings demonstrated the presence of warming and "cold-loving plants" however temperatures in oceanic waters rarely cause extinction, as temperatures have to be as high as 30°C. Although, what could have happened was an increase in oxygen intake as temperatures rose, which is an issue in oxygen-deficient waters which was the case (Wignall and Twitchett …show more content…
1155-1158).
"End-Permian catastrophe by bolide impact: Evidence of a gigantic release of sulfur from the mantle" by Kunio Kaiho, Yoschimichi Kajiwara, Takanori Nakano, Yasunori Miura, Hodaka Kawahata, Kazu Tazaki, Masto Ueshima, Zhongqiang Chen, Guang R. Shi.
The basis of the paper was the End-Permian crisis and studied the geochemical and paleontological samples from the Meishan section. Whilst evaluating the samples, there was suggestions that the mass extinction occurred simultaneously with an increase in Ni the same was found in the Cretaceous-Tertiary (K-T) boundary. In the ocean asteroidal or cometary accompanied the extinction as helium and argon were encountered in the sediments. And Fe-Si-Ni grains were found, as Fe and Ni separated and mixed with Si or Al within the oceanic crust and mantle suggesting an impact. The oceanic impact showed that approximately 99% of the Sulphur came from the mantle and thus, this could have created volcanism, and the paper states an example of the Siberian flood, as the Sulphur is usually "supplied from impact-induced volcanism." The chemical reactions 1 and 2 implied in the paper show that there was consumption of oxygen which decreased atmospheric oxygen and was dissolved in the ocean; as well as the chemical reactions show an increase in hydrogen at the time period causing acid rain. In conclusion, the increase in Ni layer, caused Sulphur to be released by the mantle, and together with the oxygen consumption and acid rain caused the mass extinction (Kaiho et al. 815-818).
Critique: Most likely cause of the P-T Mass extinction
The Permian-Triassic (P-T) mass extinction, is until today considered the most severe mass extinctions, out of approximately five major extinction occurrences in Earth's history. The duration of this mass extinction is until today one of the most debated aspects of the mass extinction. Some experts such as geologists and paleontologists believe it could have been a rapid process of about 200,000 years; however, others believe that it was a longer process, approximating 15 million years ("Permian Extinction"). Nonetheless, it is a fact that around 90% of the marine species were eradicated, and 70% of terrestrial species were eliminated (Renne et al. 1413-1416). According to some experts, only 4% of Earth's species survived. Although the timeframe is a debating aspect, the most discussed factor of the event is still the causes. There are a number of possible causes, and many of which have been studied, encompassing the flood basalt eruptions, changes drop in oxygen levels, changes in temperature, ocean level, changes in the carbon cycle, and many times, a combination of all these possible causes ("BBC Nature - Permian Mass Extinction Videos, News, And Facts").
One of the possible causes is changes in temperature or a crisis in temperature. This might have played a big role in the cause of the mass extinction. The greatest cause is the evidence found at high temperatures. The issue with high temperatures is that it affected the nutrients available to the species at the time. As well as many marine species were unable to live in overly high temperate waters, especially in the shallow waters. As Wignall and Twitchett discussed, there was evidence of "warming and cold loving-plants". Nonetheless, they argue that high temperatures would not eradicate any species unless temperatures reached a of high 30°C and evidence shows that the temperatures only rounded 25-27°C (Wignall and Twitchett 1155-1158). This was only in shallow waters, a lot of marine species are found in deeper waters, and these would not be as affected, as the photosynthetic process were uninterrupted. Ultimately, the temperature could have played a role in some aspects, but not completely on its own.
A second cause could have been changed in the carbon cycle, this discusses, the ocean anoxia, which is related to the Siberian Traps, which is discussed by Renne et al., where stated that the volcanic flood, lead to a potential marine regression, and that through this, there was a large amount of Sulphate which then lead to the creating of ice, and due to this, a large change in carbon dioxide in the environment. This is also related to the greenhouse conditions in the atmosphere. However, this then affects the ocean, and Kaiho et al., discuss that through the change in the conditions in the atmosphere, there was an increase of oxygen consumed in the oceanic waters. Creating oxygen to dissolve in the ocean, and this increase they hydrogen levels creating acidic rain. This is to show that causes are interlinked. Renne et al. discuss one this, however, this can be linked to what is studied by Kaiho et al. Without combining the two studies, it would be hard to say that the marine regression was the only cause, or that the changes in oxygenation and they would contradict each other without being put together.
Nonetheless, there are other causes that are not related to any of the above stated.
One that is considered a hot topic is the movement of the continental plates. This is the movement of the north-south plates moving towards each other, causing an alteration in ocean currents and a change in climates. If this was the case, it would contradict any other potential causes because this would eliminate any changes in the carbon cycle, oxygenation; however, temperatures could potentially have changed. The only issue with the continental plate movement is that the Pangea was already in place before the estimated time of the mass extinction occurrence ("Permian Extinction"). To conclude, a better way to look at the mass extinction and what caused it, is definitely a combination of all aspects, leading to the extinction of the species. It can be looked at as a massive
puzzle.
Word Count: 1, 319
References:
"BBC Nature - Permian Mass Extinction Videos, News And Facts". Bbc.co.uk. N.p., 2016. Web. 2 May 2016.
Kaiho, Kunio et al. "End-Permian Catastrophe By A Bolide Impact: Evidence Of A Gigantic Release Of Sulfur From The Mantle". Geol 29.9 (2001): 815. Web.
"Permian Extinction". Encyclopedia Britannica. N.p., 2015. Web. 2 May 2016.
Renne, P. R. et al. "Synchrony And Causal Relations Between Permian-Triassic Boundary Crises And Siberian Flood Volcanism". Science 269.5229 (1995): 1413-1416. Web.
Wignall, P. B. and R. J. Twitchett. "Oceanic Anoxia And The End Permian Mass Extinction". Science272.5265 (1996): 1155-1158. Web.