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- حادثة هانجنبيرج هي حادثة أحيائية حدثت في نهاية حقبة فيمينيان (العصر الديفوني المتأخر) مرتبطة بانقراضات العصر الديفوني المتأخر، ولقد كانت حادثة نقص أكسجين اتسمت بوجود السجيل الزيتي. وقد اُقترح أن هذا كان مرتبطًا بانخفاض سريع في مستوى البحر بفعل المرحلة الأخيرة من العصر الجليدي بنصف الكرة الأرضية الجنوبي بالعصر الديفوني. كما اُقترح أن هذا كان مرتبطًا بزيادة في الغطاء النباتي للأرض، مما أدى إلى زيادة تدفق العناصر الغذائية في الأنهار. وربما يكون قد أدى هذا إلى تتريف البحار فوق القارية شبه المحصورة وإلى إثارة انتشار الطحالب. لقد جاءت التسمية من سجيل هانجينبيرج، وهو جزء من تسلسل يباعد الحدود الكربونية الديفونية، عن الكتل الصخرية الراينية في ألمانيا. (ar)
- Das Hangenberg-Ereignis (auch Hangenberg-Krise), benannt nach den Schwarzschiefersedimenten am Hangenberg im Rheinischen Schiefergebirge, bezeichnet eine gravierende weltweite Umweltveränderung einschließlich eines umfassenden Massenaussterbens an der Grenze zwischen den geochronologischen Perioden Devon und Karbon vor 358,9 Millionen Jahren. Diese Biodiversitätskrise führte nach neueren Erkenntnissen zu einem Artenschwund bis 75 Prozent und erreichte damit ähnliche Dimensionen wie die fünf großen Aussterbewellen (die sogenannten „Big Five“) im Phanerozoikum, das heißt während der letzten 541 Millionen Jahre. Die Dauer der Krise wird überwiegend auf etwa 100.000 bis 300.000 Jahre geschätzt, wobei einzelne Studien eine etwas kürzere Zeitspanne postulieren. Auf der Suche nach den Ursachen wird gegenwärtig in der Wissenschaft eine Vielzahl möglicher Einflussfaktoren in Erwägung gezogen, eine alle Aspekte abdeckende Erklärung für das Artensterben steht jedoch noch aus. (de)
- The Hangenberg event, also known as the Hangenberg crisis or end-Devonian extinction, is a mass extinction that occurred at the end of the Famennian stage, the last stage in the Devonian Period (roughly 358.9 ± 0.4 million years ago). It is usually considered the second-largest extinction in the Devonian Period, having occurred approximately 13 million years after the Late Devonian mass extinction (Kellwasser event) at the Frasnian-Famennian boundary. The Hangenberg event was an anoxic event marked by a layer of black shale, and it has been proposed to have been related to a rapid sea-level fall from the last phase of the Devonian Southern Hemisphere glaciation. It has also been suggested to have been linked to an increase in terrestrial plant cover. That would have led to increased nutrient supply in rivers and may have led to eutrophication of semi-restricted epicontinental seas and could have stimulated algal blooms. However, support for a rapid increase in plant cover at the end of the Famennian is lacking. The event is named after the Hangenberg Shale, which is part of a sequence that straddles the Devonian-Carboniferous boundary in the Rhenish Massif of Germany. One hypothesis for the cause of the last pulse of the extinction notes the abundance of malformed plant spores at the Devonian-Carboniferous boundary. This could implicate increased UV-B radiation and ozone depletion as the kill mechanism, at least for terrestrial organisms. Intense warming may lead to increased convection of water vapor in the atmosphere, reacting to inorganic chlorine compounds and producing ClO, an ozone-depleting compound. However, this mechanism has been criticized for its slow and weak effect on ozone concentrations, as well as its suspect rejection of volcanic influences. Alternatively, cosmic rays from a nearby supernova would be capable of a similar degree of ozone depletion. The impact of a nearby supernova can be supported or refuted by testing for trace amounts of Plutonium-244 in fossils, but these tests have yet to be published. Ozone depletion could just as easily be explained by an increase in greenhouse gas concentrations resulting from an intense period of arc volcanism. The spore malformations may not even be related to UV radiation in the first place, and could simply be a result of volcanism-related environmental pressures such as acid rain. (en)
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- Placoderms went extinct in the Hangenberg Event, and sarcopterygians also suffered heavy losses. (en)
- Ammonoids nearly died out in the Hangenberg Event, while phacopid trilobites , stromatoporoid sponges , and chitinozoans all went extinct. (en)
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- Cymaclymenia01.jpg (en)
- D Terrelli.png (en)
- Kainops raymondi.JPG (en)
- StromatoporoidTopDevColumbus.jpg (en)
- Various Porolepiformes.jpg (en)
- Whole chitinozoan cropped.jpg (en)
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- حادثة هانجنبيرج هي حادثة أحيائية حدثت في نهاية حقبة فيمينيان (العصر الديفوني المتأخر) مرتبطة بانقراضات العصر الديفوني المتأخر، ولقد كانت حادثة نقص أكسجين اتسمت بوجود السجيل الزيتي. وقد اُقترح أن هذا كان مرتبطًا بانخفاض سريع في مستوى البحر بفعل المرحلة الأخيرة من العصر الجليدي بنصف الكرة الأرضية الجنوبي بالعصر الديفوني. كما اُقترح أن هذا كان مرتبطًا بزيادة في الغطاء النباتي للأرض، مما أدى إلى زيادة تدفق العناصر الغذائية في الأنهار. وربما يكون قد أدى هذا إلى تتريف البحار فوق القارية شبه المحصورة وإلى إثارة انتشار الطحالب. (ar)
- Das Hangenberg-Ereignis (auch Hangenberg-Krise), benannt nach den Schwarzschiefersedimenten am Hangenberg im Rheinischen Schiefergebirge, bezeichnet eine gravierende weltweite Umweltveränderung einschließlich eines umfassenden Massenaussterbens an der Grenze zwischen den geochronologischen Perioden Devon und Karbon vor 358,9 Millionen Jahren. Diese Biodiversitätskrise führte nach neueren Erkenntnissen zu einem Artenschwund bis 75 Prozent und erreichte damit ähnliche Dimensionen wie die fünf großen Aussterbewellen (die sogenannten „Big Five“) im Phanerozoikum, das heißt während der letzten 541 Millionen Jahre. (de)
- The Hangenberg event, also known as the Hangenberg crisis or end-Devonian extinction, is a mass extinction that occurred at the end of the Famennian stage, the last stage in the Devonian Period (roughly 358.9 ± 0.4 million years ago). It is usually considered the second-largest extinction in the Devonian Period, having occurred approximately 13 million years after the Late Devonian mass extinction (Kellwasser event) at the Frasnian-Famennian boundary. The Hangenberg event was an anoxic event marked by a layer of black shale, and it has been proposed to have been related to a rapid sea-level fall from the last phase of the Devonian Southern Hemisphere glaciation. It has also been suggested to have been linked to an increase in terrestrial plant cover. That would have led to increased nutrie (en)
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- حادثة هانجنبيرج (ar)
- Hangenberg-Ereignis (de)
- Hangenberg event (en)
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