Calage stratigraphique des diagraphies du Jurassique du sud du bassin Parisien a partir du sondage de Sancerre-Couy (Programme Geologie profonde de la France)

Lorenz, C.; Lefavrais, A.; Lorenz, Jacqueline; Marchand, Didier; Millon, René

doi:10.2113/gssgfbull.162.5.947

Cited by 7 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our revised ammonite biostratigraphic framework (Section 2, Plate S1) shows serious differences with the old framework (Lorenz et al, 1987(Lorenz et al, , 1991. Therefore, we see that it is reasonable to compare our results with the previous Geologic Time Scale 2004, GTS2004 (Gradstein et al, 2004).…”

Section: The Toarcian Timescalementioning

confidence: 50%

“…Detrital minerals are represented by clays (illite and chlorite) and quartz (Delavenna et al, 1989). Interpreted !black shales" are situated between core depths 348.32 m and 336.9 m (Lorenz et al, 1991;Hermoso et al, 2009a). The CIE is easily recognized in the core with an amplitude of !6 ‰ in the bulk carbonate !…”

Section: Stratigraphic Framework Of the Toarcian Sancerre Corementioning

confidence: 98%

“…It is an ultra-deep drill-core encompassing Carboniferous to Middle Jurassic strata. It was drilled in 1986It was drilled in -1987 with the aim to study the magnetic anomaly of the Paris Basin (GPF program !Géologie Profonde de la France", Lorenz et al, 1987). The Toarcian Stage in the SancerreCouy core is 158-m thick, spanning ~354.3 to ~196.3 m depth (Fig.…”

Section: Stratigraphic Framework Of the Toarcian Sancerre Corementioning

confidence: 99%

“…The ammonite biostratigraphy was previously established by Lorenz et al (1987Lorenz et al ( , 1991 and was revised in this study with greater accuracy. Most of Toarcian ammonite zones were recognized; the lower and upper boundaries of the Toarcian Stage can be defined with high precision (Figs.…”

Section: Stratigraphic Framework Of the Toarcian Sancerre Corementioning

confidence: 99%

“…The recent Geologic Time Scale, GTS2012 (Gradstein et al, 2012) adopted our 405 kyr tuning of magnetic susceptibility at Sancerre (Huang et al, 2010 but unfortunately this was applied to a poorly constrained biostratigraphic framework (Lorenz et al, 1987(Lorenz et al, , 1991, conjointly with selected radio-isotopic ages to infer durations of Toarcian ammonite zones (Gradstein et al, 2012, their Table 26.3). Our revised ammonite biostratigraphic framework (Section 2, Plate S1) shows serious differences with the old framework (Lorenz et al, 1987(Lorenz et al, , 1991.…”

Section: The Toarcian Timescalementioning

confidence: 99%

See 4 more Smart Citations

Astronomical calibration of the Toarcian Stage: Implications for sequence stratigraphy and duration of the early Toarcian OAE

Boulila

Galbrun

Huret

et al. 2014

Earth and Planetary Science Letters

160

138

View full text Add to dashboard Cite

The Toarcian Oceanic Anoxic Event (T-OAE) of the early Jurassic period involves one of the largest perturbations of the carbon cycle in the past 250 Ma, recorded by a pronounced negative carbon-isotope excursion (CIE). Numerous studies have focused on potential causes of the T-OAE and CIE, but are hampered by an uncertain timescale. Here we present high-resolution (!2 kyr) magnetic susceptibility (MS) measurements from the marine marls of the Sancerre-Couy drill-core, southern Paris Basin, spanning the entire Toarcian Stage. The MS variations document a rich series of sub-Milankovitch to Milankovitch frequencies (precession, obliquity and eccentricity) with the periodic g 2 -g 5 (405 kyr) and quasi-periodic g 4 -g 3 (!2.4 Myr Cenozoic mean periodicity) eccentricity terms being the most prominent. The MS-related g 4 -g 3 variation reflects third-order eustatic sequences, and constrains the sequence stratigraphic framework of the Toarcian Stage. In addition, MS variations reveal a modulation of g 2 -g 5 by g 4 -g 3 eccentricity related cycles, suggesting that sea-level change was the main control on the deposition of the Toarcian Sancerre marls, in tune with the astro-climatic frequencies. The stable 405 kyr cyclicity constrains a minimum duration of the Toarcian Stage to !8.3 Myr, and the well documented CIE, associated with the T-OAE, to !300 to 500 kyr. The 405 kyr MS timescale calibrates the periodicity of the prominent high-frequency ! 13 C cycles that occur in the decreasing part of the CIE to 30 to 34 kyr, consistent with the Toarcian obliquity period predicted for an Earth experiencing sustained tidal dissipation.

show abstract

Section: The Toarcian Timescalementioning

confidence: 50%

Section: Stratigraphic Framework Of the Toarcian Sancerre Corementioning

confidence: 98%

Section: Stratigraphic Framework Of the Toarcian Sancerre Corementioning

confidence: 99%

Section: Stratigraphic Framework Of the Toarcian Sancerre Corementioning

confidence: 99%