TY - JOUR
T1 - A new correlation of Triassic-Jurassic boundary successions in NW Europe, Nevada and Peru, and the Central Atlantic Magmatic Province
T2 - A time-line for the end-Triassic mass extinction
AU - Lindström, Sofie
AU - van de Schootbrugge, Bas
AU - Hansen, Katrine Hartung
AU - Pedersen, Gunver Krarup
AU - Alsen, Peter
AU - Thibault, Nicolas Rudolph
AU - Dybkjaer, Karen
AU - Bjerrum, Christian J.
AU - Nielsen, Lars Henrik
PY - 2017/7/15
Y1 - 2017/7/15
N2 - Understanding the end-Triassic mass extinction event (201.36Ma) requires a clear insight into the stratigraphy of boundary sections, which allows for long-distance correlations and correct distinction of the sequence of events. However, even after the ratification of a Global Stratotype Section and Point, global correlations of TJB successions are hampered by the fact that many of the traditionally used fossil groups were severely affected by the crisis. Here, a new correlation of key TJB successions in Europe, U.S.A. and Peru, based on a combination of biotic (palynology and ammonites), geochemical (δ13Corg) and radiometric (U/Pb ages) constraints, is presented. This new correlation has an impact on the causality and temporal development during the end-Triassic event. It challenges the hitherto used standard correlation, which has formed the basis for a hypothesis that the extinction was caused by more or less instantaneous release of large quantities of light carbon (methane) to the atmosphere, with catastrophic global warming as a consequence. The new correlation instead advocates a more prolonged scenario with a series of feedback mechanisms, as it indicates that the bulk of the hitherto dated, high-titanium, quartz normalized volcanism of the Central Atlantic Magmatic Province (CAMP) preceded or was contemporaneous to the onset of the mass extinction. In addition, the maximum phase of the mass extinction, which affected both the terrestrial and marine ecosystems, was associated with a major regression and repeated, enhanced earthquake activity in Europe. A subsequent transgression resulted in the formation of hiati or condensed successions in many areas in Europe. Later phases of volcanic activity of the CAMP, producing low titanium, quartz normalized and high-iron, quartz normalized basaltic rocks, continued close to the first occurrence of Jurassic ammonites and the defined TJB. During this time the terrestrial ecosystem had begun to recover, but the marine ecosystem remained disturbed.
AB - Understanding the end-Triassic mass extinction event (201.36Ma) requires a clear insight into the stratigraphy of boundary sections, which allows for long-distance correlations and correct distinction of the sequence of events. However, even after the ratification of a Global Stratotype Section and Point, global correlations of TJB successions are hampered by the fact that many of the traditionally used fossil groups were severely affected by the crisis. Here, a new correlation of key TJB successions in Europe, U.S.A. and Peru, based on a combination of biotic (palynology and ammonites), geochemical (δ13Corg) and radiometric (U/Pb ages) constraints, is presented. This new correlation has an impact on the causality and temporal development during the end-Triassic event. It challenges the hitherto used standard correlation, which has formed the basis for a hypothesis that the extinction was caused by more or less instantaneous release of large quantities of light carbon (methane) to the atmosphere, with catastrophic global warming as a consequence. The new correlation instead advocates a more prolonged scenario with a series of feedback mechanisms, as it indicates that the bulk of the hitherto dated, high-titanium, quartz normalized volcanism of the Central Atlantic Magmatic Province (CAMP) preceded or was contemporaneous to the onset of the mass extinction. In addition, the maximum phase of the mass extinction, which affected both the terrestrial and marine ecosystems, was associated with a major regression and repeated, enhanced earthquake activity in Europe. A subsequent transgression resulted in the formation of hiati or condensed successions in many areas in Europe. Later phases of volcanic activity of the CAMP, producing low titanium, quartz normalized and high-iron, quartz normalized basaltic rocks, continued close to the first occurrence of Jurassic ammonites and the defined TJB. During this time the terrestrial ecosystem had begun to recover, but the marine ecosystem remained disturbed.
KW - Ammonites
KW - Carbon isotopes
KW - Geochronology
KW - Hettangian
KW - Palynology
KW - Rhaetian
U2 - 10.1016/j.palaeo.2016.12.025
DO - 10.1016/j.palaeo.2016.12.025
M3 - Journal article
AN - SCOPUS:85009275279
SN - 0031-0182
VL - 478
SP - 80
EP - 102
JO - Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences
JF - Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences
ER -
