Changes

The Permian-Triassic boundary was characterized at a global scale by low sea level, reflected by widespread continental or shallow marine facies. The beginning of Triassic time was characterized by a sea-level rise that can be traced worldwide.

The Permian-Triassic boundary was characterized at a global scale by low sea level, reflected by widespread continental or shallow marine facies. The beginning of Triassic time was characterized by a sea-level rise that can be traced worldwide.

The end Permian crisis is generally considered the most dramatic extinction of the last 600 million years<ref name=Erwin_2006>Erwin, D. H., 2006, Extinction: How life on Earth nearly ended 250 million years ago: Princeton University Press, 296 p.</ref> and led to the extinction of 75–96% of species. Some of the invoked mechanisms included rapid sea-level change and/or anoxia or euxinia (e.g., Wignall and Twitchett,<ref name=Wignallandtwitchett_2002>Wignall, P. B., and Twitchett, R. J., 2002, Permian-Triassic sedimentology of Jameson Land, East Greenland: Incised submarine channels in an anoxic basin: Journal of the Geological Society, v. 159, p. 691–703.</ref> Hays et al.<ref name=Haysetal_2007>Hays, L. E., Beatty, T., Henderson, C. M., Love, G. D., and Summons, R. E., 2007, Evidence for photic zone euxinia through the end-Permian mass extinction in the Panthalassic Ocean (Peace River Basin, Western Canada): Palaeoworld, v. 16, p. 39–50.</ref>); extraterrestrial impact (e.g., Becker et al.<ref name=Beckeretal_2001>Becker, L., Poreda, R. J., Hunt, A. G., Bunch, T. E., and Rampino, M., 2001, Impact event at the Permo-Triassic boundary: Evidence from extraterrestrial noble gases in Fullerenes: Science, v. 291, p. 1530–1533.</ref>); enormous volcanic eruptions and/or an extreme global warming (e.g., Kidder and Worsley,<ref name=Kidderandworsley_2004>Kidder, D. L., and Worsley, T. R., 2004, Causes and consequences of extreme Permo-Triassic warming to globally equable climate and relation to the Permo-Triassic extinction and recovery: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 203, p. 207–237.</ref> Svensen et al.,<ref name=Svensenetal_2008>Svensen, H., Planke, S., Polozov, A.,G., Schimdbauer, N., Corfu, F., Podladchikov. Y. Y., and Jamtveit, B., 2008, Siberian gas venting and the end-Permian environmental crisis: Earth and Planetary Science Letters, v. 277, p. 490–500.</ref> Reichow et al.<ref name=Reichowetal_2009>Reichow, M. K. et al., 2009, The timing and extent of the eruption of the Siberian Traps large igneous province: Implications for the end-Permian environmental crisis: Earth and Planetary Science Letters, v. 277, no. 1-2, p. 9–20.</ref>); or ozone layer collapse (e.g., Beerling et al.<ref name=Beerlingetal_2007>Beerling, D. J., Harfoot, M., Lomax, B., and Pyle, J. A., 2007, The stability of the stratospheric ozone layer during the end-Permian eruption of the Siberian traps: Philosophical transactions of the Royal Society, Mathematical, Physical and Engineering Sciences, v. 365, p. 1843–1866.</ref>). The pattern of the latest Permian extinction evaluated statistically<ref name=Jinetal_2000>Jin, Y. G., Wang, Y., Wang, W., Shang, Q. H., Cao, C. Q., and Erwin, D. H., 2000, Pattern of marine mass extinction near the Permo-Triassic boundary in South China: Science, v. 289, p. 432–436.</ref> <ref name=Shenetal_2006>Shen, S. Z., Cao, C. Q., Henderson, C. M., Wang, X. D., Shi, G. R., Wang, Y., and Wang, W., 2006, End-Permian mass extinction pattern in the northern peri-Gondwanan region: Palaeoworld, v. 15, p. 3–30.</ref> <ref name=Grovesetal_2007> <ref name=Angiolinietal_2010>Angiolini, L., Checconi, A., Rettori, R., and Gaetani, M., 2010, The latest Permian mass extinction in the Alborz Mountains (North Iran). In press in Geological Journal.</ref> indicates that the extinction was a sudden event occurring during a sea-level rise. The evidence that the extinction was abrupt in different latest Permian paleogeographic settings is consistent with scenarios in which mass extinction resulted from climatic and environmental deterioration triggered by the Siberian Traps volcanism, which also increased greenhouse gas emissions into the atmosphere and thus global warming and ozone depletion. This is also supported by the pronounced negative &Delta;13C excursion recorded worldwide near the latest Permian extinction event (e.g., Baud et al.,<ref name=Baudetal_1989>Baud, A., Magaritz, M., and Holser, W. T., 1989, Permian-Triassic of the Tethys: Carbon isotopes studies: Geologische Rundschau, v. 78, no. 2, p. 649–677.</ref> Retallack and Krull,<ref name=Retallackandkrull_2006>Retallack, G. J., and Krull, E. S., 2006, Carbon isotopic evidence for terminal Permian methane outbursts and their role in extinctions of animal, plants, coral reefs, and peat swamps, in Wetlands through time: S. F. Greb and W. A. Di Michele, eds., GSA Special Paper, v. 399, p. 249–268.</ref> Horacek et al.<ref name=Horaceketal_2007>Horacek, M., Richoz, S., Brandner, R., Krystyn, L., and Spotl, C., 2007, Evidence for recurrent changes in Lower Triassic oceanic circulation of the Tethys: The &Delta;13C record from marine sections in Iran: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 252, p. 255–369.</ref>).

The end Permian crisis is generally considered the most dramatic extinction of the last 600 million years<ref name=Erwin_2006>Erwin, D. H., 2006, Extinction: How life on Earth nearly ended 250 million years ago: Princeton University Press, 296 p.</ref> and led to the extinction of 75–96% of species. Some of the invoked mechanisms included rapid sea-level change and/or anoxia or euxinia (e.g., Wignall and Twitchett,<ref name=Wignallandtwitchett_2002>Wignall, P. B., and Twitchett, R. J., 2002, Permian-Triassic sedimentology of Jameson Land, East Greenland: Incised submarine channels in an anoxic basin: Journal of the Geological Society, v. 159, p. 691–703.</ref> Hays et al.<ref name=Haysetal_2007>Hays, L. E., Beatty, T., Henderson, C. M., Love, G. D., and Summons, R. E., 2007, Evidence for photic zone euxinia through the end-Permian mass extinction in the Panthalassic Ocean (Peace River Basin, Western Canada): Palaeoworld, v. 16, p. 39–50.</ref>); extraterrestrial impact (e.g., Becker et al.<ref name=Beckeretal_2001>Becker, L., Poreda, R. J., Hunt, A. G., Bunch, T. E., and Rampino, M., 2001, Impact event at the Permo-Triassic boundary: Evidence from extraterrestrial noble gases in Fullerenes: Science, v. 291, p. 1530–1533.</ref>); enormous volcanic eruptions and/or an extreme global warming (e.g., Kidder and Worsley,<ref name=Kidderandworsley_2004>Kidder, D. L., and Worsley, T. R., 2004, Causes and consequences of extreme Permo-Triassic warming to globally equable climate and relation to the Permo-Triassic extinction and recovery: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 203, p. 207–237.</ref> Svensen et al.,<ref name=Svensenetal_2008>Svensen, H., Planke, S., Polozov, A.,G., Schimdbauer, N., Corfu, F., Podladchikov. Y. Y., and Jamtveit, B., 2008, Siberian gas venting and the end-Permian environmental crisis: Earth and Planetary Science Letters, v. 277, p. 490–500.</ref> Reichow et al.<ref name=Reichowetal_2009>Reichow, M. K. et al., 2009, The timing and extent of the eruption of the Siberian Traps large igneous province: Implications for the end-Permian environmental crisis: Earth and Planetary Science Letters, v. 277, no. 1-2, p. 9–20.</ref>); or ozone layer collapse (e.g., Beerling et al.<ref name=Beerlingetal_2007>Beerling, D. J., Harfoot, M., Lomax, B., and Pyle, J. A., 2007, The stability of the stratospheric ozone layer during the end-Permian eruption of the Siberian traps: Philosophical transactions of the Royal Society, Mathematical, Physical and Engineering Sciences, v. 365, p. 1843–1866.</ref>). The pattern of the latest Permian extinction evaluated statistically<ref name=Jinetal_2000>Jin, Y. G., Wang, Y., Wang, W., Shang, Q. H., Cao, C. Q., and Erwin, D. H., 2000, Pattern of marine mass extinction near the Permo-Triassic boundary in South China: Science, v. 289, p. 432–436.</ref> <ref name=Shenetal_2006>Shen, S. Z., Cao, C. Q., Henderson, C. M., Wang, X. D., Shi, G. R., Wang, Y., and Wang, W., 2006, End-Permian mass extinction pattern in the northern peri-Gondwanan region: Palaeoworld, v. 15, p. 3–30.</ref> <ref name=Grovesetal_2007>Groves, J. R., Rettori, R., Payne, J. L., Boyce, M. D., and Altiner D., 2007, End-Permian mass extinction of Lagenide foraminifers in the southern Alps (northern Italy): Journal of Paleontology, v. 81, p. 415–434.</ref> <ref name=Angiolinietal_2010>Angiolini, L., Checconi, A., Rettori, R., and Gaetani, M., 2010, The latest Permian mass extinction in the Alborz Mountains (North Iran). In press in Geological Journal.</ref> indicates that the extinction was a sudden event occurring during a sea-level rise. The evidence that the extinction was abrupt in different latest Permian paleogeographic settings is consistent with scenarios in which mass extinction resulted from climatic and environmental deterioration triggered by the Siberian Traps volcanism, which also increased greenhouse gas emissions into the atmosphere and thus global warming and ozone depletion. This is also supported by the pronounced negative &delta;13C excursion recorded worldwide near the latest Permian extinction event (e.g., Baud et al.,<ref name=Baudetal_1989>Baud, A., Magaritz, M., and Holser, W. T., 1989, Permian-Triassic of the Tethys: Carbon isotopes studies: Geologische Rundschau, v. 78, no. 2, p. 649–677.</ref> Retallack and Krull,<ref name=Retallackandkrull_2006>Retallack, G. J., and Krull, E. S., 2006, Carbon isotopic evidence for terminal Permian methane outbursts and their role in extinctions of animal, plants, coral reefs, and peat swamps, in Wetlands through time: S. F. Greb and W. A. Di Michele, eds., GSA Special Paper, v. 399, p. 249–268.</ref> Horacek et al.<ref name=Horaceketal_2007>Horacek, M., Richoz, S., Brandner, R., Krystyn, L., and Spotl, C., 2007, Evidence for recurrent changes in Lower Triassic oceanic circulation of the Tethys: The &delta;13C record from marine sections in Iran: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 252, p. 255–369.</ref>).

[[file:M106Ch01Fig07.jpg|thumb|300px|{{figure number|7}}Global paleogeography (top) and major depositional settings in the southern margin of the Tethys (below) during Norian time (about 205 Ma).]]

[[file:M106Ch01Fig07.jpg|thumb|300px|{{figure number|7}}Global paleogeography (top) and major depositional settings in the southern margin of the Tethys (below) during Norian time (about 205 Ma).]]