Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes
<div>Determination of the causes of the Permian -Triassic boundary</div><div>(PTB) biotic crisis is hindered primarily by the diachronous nature of</div><div>the used PTB, poor stratigraphic control of compared Upper Permian</div><div>and Lower Triassic faun...
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| Format: | Article |
| Language: | English |
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Croatian Geological Survey
2010-11-01
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| Series: | Geologia Croatica |
| Subjects: | |
| Online Access: | http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/283 |
| _version_ | 1818153252151099392 |
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| author | Heinz W. Kozur |
| author_facet | Heinz W. Kozur |
| author_sort | Heinz W. Kozur |
| collection | DOAJ |
| description | <div>Determination of the causes of the Permian -Triassic boundary</div><div>(PTB) biotic crisis is hindered primarily by the diachronous nature of</div><div>the used PTB, poor stratigraphic control of compared Upper Permian</div><div>and Lower Triassic faunas, espec ially in cont inental biotopes, poor</div><div>knowledge of the lower and middle Scythian faunas from m,UlY environments, and by interpolation of the unknown (lower and middle)</div><div>Scythian diversity from the known Upper Pennian and Middle Triassic</div><div>diversity data in many major fossil gro ups. Most of these problems</div><div>can be reso lved by using the firs t appearance datum (FAD) of</div><div>Nil1deodlls pan'Ii,I' as either an isochronous PTB, or as an isochronous</div><div>marker [eve I very dose 10 lhe base of lhe Triassi c; careful studies of</div><div>fossil-rich, comp[ele conlinental boundary sections (e.g., Dalongkou</div><div>in Sinkiang), and uti li sation of uninterpoJated diversity data, which</div><div>are based on known Scythian data, for the reconstruction of the</div><div>extinction and recovery patterns in all fossil groups.</div><div>The most important features of the PTB biotic crisis arc: (I)</div><div>Among the marine biota, only the plankton and the wann-water benthos,</div><div>nektobenthos and nekton are strongly affected by the PTB biotic</div><div>crisis. (2) The recovery of the warm-water nekton and nektobenthos</div><div>was very fast (after one conodont zone). The recovery of the warmwater</div><div>benthos, some of the plankton (radiolarians) and the terrestrial</div><div>plant product ivity was strongly delayed for several million years, and</div><div>occurred on ly in the upper Ol enekian (upper Scythian) and in the</div><div>Middle Triassic. (3) The number of the Lazarus taxa that re-appeared</div><div>in the upper Olenekian and above all in the Middle Triassic, is very</div><div>high (about 50%) and in some fossi l groups 90-100% at generic level.</div><div>The reconstruction of the scenario for the PTB biotic crisis</div><div>requires not only the conside'rlItion of the uninterpolaled extinction</div><div>and recovery patterns of all foss il groups across all envi ronments, but</div><div>must also account for the main feat ures of geological evolution from</div><div>the Middle Permian to the Lower Triassic. The most important causal</div><div>factors in the PTB biotic crisis are the ex tinction event at the</div><div>Guadalupian-Lopingian boundary that restricted the diverse Upper</div><div>Permian wann-water benthos 10 the Tet hyan shelves, the long-[asling,</div><div>widespread Siberian Trap volcanism (Dzhulfian - lower Scythian)</div><div>which was Ihe grealest volcanic event during the Phanerozoic, and (he</div><div>very strong explosive felsic 10 intermediate volcanism around the</div><div>PTB, close to the margin between eastern Tethys and Panlhalassa.</div><div>These volcanic activities resulted in those climatic changes that were</div><div>dircclly and indireclly (as cause of the oceanic sll peranoxia) responsi ble</div><div>for the PTB biotic crisis, such as periodic cooling of Ihe climate</div><div>by volcanic dust and sulphate aerosols (mai nly caused by the Siberian</div><div>Trap volcanism), acid rain, a 3-6 month "vo[canic winter" at low lat iIlldes</div><div>and Ihe strongly reduced inpul of sunl ight during the uppennost</div><div>Dorashamian (both caused by lhe very strong explosive volcanism at</div><div>the Tethys/Panthalassa margin), followed by global warming in the</div><div>lower Scythian, and uppennost Dorashamian to lower Scylhian superanoxia.</div> |
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| id | doaj.art-d5d434ef0fc148a5aadb4a61b1a0eda6 |
| institution | Directory Open Access Journal |
| issn | 1330-030X 1333-4875 |
| language | English |
| last_indexed | 2024-12-11T14:07:39Z |
| publishDate | 2010-11-01 |
| publisher | Croatian Geological Survey |
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| series | Geologia Croatica |
| spelling | doaj.art-d5d434ef0fc148a5aadb4a61b1a0eda62022-12-22T01:03:36ZengCroatian Geological SurveyGeologia Croatica1330-030X1333-48752010-11-0151213516210.4154/GC.1998.12194Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its CausesHeinz W. Kozur0Turkiye Petrolleri A.O.<div>Determination of the causes of the Permian -Triassic boundary</div><div>(PTB) biotic crisis is hindered primarily by the diachronous nature of</div><div>the used PTB, poor stratigraphic control of compared Upper Permian</div><div>and Lower Triassic faunas, espec ially in cont inental biotopes, poor</div><div>knowledge of the lower and middle Scythian faunas from m,UlY environments, and by interpolation of the unknown (lower and middle)</div><div>Scythian diversity from the known Upper Pennian and Middle Triassic</div><div>diversity data in many major fossil gro ups. Most of these problems</div><div>can be reso lved by using the firs t appearance datum (FAD) of</div><div>Nil1deodlls pan'Ii,I' as either an isochronous PTB, or as an isochronous</div><div>marker [eve I very dose 10 lhe base of lhe Triassi c; careful studies of</div><div>fossil-rich, comp[ele conlinental boundary sections (e.g., Dalongkou</div><div>in Sinkiang), and uti li sation of uninterpoJated diversity data, which</div><div>are based on known Scythian data, for the reconstruction of the</div><div>extinction and recovery patterns in all fossil groups.</div><div>The most important features of the PTB biotic crisis arc: (I)</div><div>Among the marine biota, only the plankton and the wann-water benthos,</div><div>nektobenthos and nekton are strongly affected by the PTB biotic</div><div>crisis. (2) The recovery of the warm-water nekton and nektobenthos</div><div>was very fast (after one conodont zone). The recovery of the warmwater</div><div>benthos, some of the plankton (radiolarians) and the terrestrial</div><div>plant product ivity was strongly delayed for several million years, and</div><div>occurred on ly in the upper Ol enekian (upper Scythian) and in the</div><div>Middle Triassic. (3) The number of the Lazarus taxa that re-appeared</div><div>in the upper Olenekian and above all in the Middle Triassic, is very</div><div>high (about 50%) and in some fossi l groups 90-100% at generic level.</div><div>The reconstruction of the scenario for the PTB biotic crisis</div><div>requires not only the conside'rlItion of the uninterpolaled extinction</div><div>and recovery patterns of all foss il groups across all envi ronments, but</div><div>must also account for the main feat ures of geological evolution from</div><div>the Middle Permian to the Lower Triassic. The most important causal</div><div>factors in the PTB biotic crisis are the ex tinction event at the</div><div>Guadalupian-Lopingian boundary that restricted the diverse Upper</div><div>Permian wann-water benthos 10 the Tet hyan shelves, the long-[asling,</div><div>widespread Siberian Trap volcanism (Dzhulfian - lower Scythian)</div><div>which was Ihe grealest volcanic event during the Phanerozoic, and (he</div><div>very strong explosive felsic 10 intermediate volcanism around the</div><div>PTB, close to the margin between eastern Tethys and Panlhalassa.</div><div>These volcanic activities resulted in those climatic changes that were</div><div>dircclly and indireclly (as cause of the oceanic sll peranoxia) responsi ble</div><div>for the PTB biotic crisis, such as periodic cooling of Ihe climate</div><div>by volcanic dust and sulphate aerosols (mai nly caused by the Siberian</div><div>Trap volcanism), acid rain, a 3-6 month "vo[canic winter" at low lat iIlldes</div><div>and Ihe strongly reduced inpul of sunl ight during the uppennost</div><div>Dorashamian (both caused by lhe very strong explosive volcanism at</div><div>the Tethys/Panthalassa margin), followed by global warming in the</div><div>lower Scythian, and uppennost Dorashamian to lower Scylhian superanoxia.</div>http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/283PIT boundaryBiotic crisisExtinction and recovery patternsVolcanic winterSuperanoxia |
| spellingShingle | Heinz W. Kozur Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes Geologia Croatica PIT boundary Biotic crisis Extinction and recovery patterns Volcanic winter Superanoxia |
| title | Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes |
| title_full | Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes |
| title_fullStr | Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes |
| title_full_unstemmed | Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes |
| title_short | Problems for Evaluation of the Scenario of the Permian -Triassic Boundary Biotic Crisis and of Its Causes |
| title_sort | problems for evaluation of the scenario of the permian triassic boundary biotic crisis and of its causes |
| topic | PIT boundary Biotic crisis Extinction and recovery patterns Volcanic winter Superanoxia |
| url | http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/283 |
| work_keys_str_mv | AT heinzwkozur problemsforevaluationofthescenarioofthepermiantriassicboundarybioticcrisisandofitscauses |