TY - JOUR

T1 - Perturbation of the carbon cycle during the late Pliensbachian - early Toarcian

T2 - New insight from high-resolution carbon isotope records in Morocco

AU - Bodin, Stéphane

AU - Krencker, Francois Nicolas

AU - Kothe, Tim

AU - Hoffmann, René

AU - Mattioli, Emanuela

AU - Heimhofer, Ulrich

AU - Kabiri, Lahcen

N1 - Funding Information: This research was financed by the Deutsche Forschungsgemeinschaft (DFG, project n° BO 3655/1–2). We would like to thank Martin Hönig for its assistance in the field. Guillaume Suan and Felix Schlagintweit are gratefully acknowledged for their help in the field, and incertae sedis identification, respectively. Analytical work in the isotope laboratories at Bochum and Hannover was supported by Andrea Niedermayr and Christiane Wenske, respectively. We acknowledge Karl Föllmi and Matias Reolid for their constructive reviews.

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Preceding the early Toarcian Oceanic Anoxic Event by ~1Myr, the Pliensbachian-Toarcian boundary event is in many aspects as severe and disturbing for the environment as its better-studied successor. Both events are associated with rapid and pronounced global warming, major faunal and floral turnover, increased hydrological cycling and dramatic collapses of carbonate production. To better characterize the Pliensbachian-Toarcian boundary event, a high-resolution, paired carbonate and organic matter carbon isotope survey of three sections from the Central High Atlas Basin of Morocco has been undertaken. A pronounced negative shift in the carbonate carbon-isotope record, not paralleled by a similar excursion in the organic carbon, can be linked to the collapse of the neritic carbonate factory in the earliest Toarcian. These results show that, contrary to the Toarcian Oceanic Anoxic Event, a rapid and massive injection of 13C-depleted carbon into the atmosphere is not responsible for the environmental perturbations observed during the Pliensbachian-Toarcian boundary event. However, input of isotopically non-depleted carbon such as mantle source CO2 into the atmosphere as a potential cause for the Pliensbachian-Toarcian boundary event cannot be excluded. This would most probably be sourced from an early pulse of the Karoo-Ferrar Large Igneous Province.

AB - Preceding the early Toarcian Oceanic Anoxic Event by ~1Myr, the Pliensbachian-Toarcian boundary event is in many aspects as severe and disturbing for the environment as its better-studied successor. Both events are associated with rapid and pronounced global warming, major faunal and floral turnover, increased hydrological cycling and dramatic collapses of carbonate production. To better characterize the Pliensbachian-Toarcian boundary event, a high-resolution, paired carbonate and organic matter carbon isotope survey of three sections from the Central High Atlas Basin of Morocco has been undertaken. A pronounced negative shift in the carbonate carbon-isotope record, not paralleled by a similar excursion in the organic carbon, can be linked to the collapse of the neritic carbonate factory in the earliest Toarcian. These results show that, contrary to the Toarcian Oceanic Anoxic Event, a rapid and massive injection of 13C-depleted carbon into the atmosphere is not responsible for the environmental perturbations observed during the Pliensbachian-Toarcian boundary event. However, input of isotopically non-depleted carbon such as mantle source CO2 into the atmosphere as a potential cause for the Pliensbachian-Toarcian boundary event cannot be excluded. This would most probably be sourced from an early pulse of the Karoo-Ferrar Large Igneous Province.

KW - Carbonate mud shedding

KW - Carbonate platform demise

KW - Early jurassic

KW - Methane hydrate

KW - Organic and carbonate carbon isotopes

UR - http://www.scopus.com/inward/record.url?scp=84952918118&partnerID=8YFLogxK

U2 - 10.1016/j.jafrearsci.2015.12.018

DO - 10.1016/j.jafrearsci.2015.12.018

M3 - Article

AN - SCOPUS:84952918118

VL - 116

SP - 89

EP - 104

JO - Journal of African earth sciences

JF - Journal of African earth sciences

SN - 1464-343X

ER -