10.6084/m9.figshare.3453146.v1
Baptiste Sucheras-Marx
Baptiste
Sucheras-Marx
Fabienne Giraud
Fabienne
Giraud
Vincent Fernandez
Vincent
Fernandez
Bernard Pittet
Bernard
Pittet
Christophe Lecuyer
Christophe
Lecuyer
Davide Olivero
Davide
Olivero
Emanuela Mattioli
Emanuela
Mattioli
Duration of the Early Bajocian and the associated δ<sup>13</sup>C positive excursion based on cyclostratigraphy
Geological Society of London
2016
cyclostratigraphic analysis
carbonate content
ocean eutrophication
duration
marine invertebrates
climax isotope values
carbon isotope values
Bajocian
δ 13 C
latitude
French Subalpine Basin
palaeoenvironmental changes
δ 13 C excursion
172 Ma
tectonic changes
2.72 Ma
greyscale variations
Les Dourbes section
Chaudon
4.082 Ma
1.36 Ma
Geology
2016-06-21 11:10:38
Dataset
https://geolsoc.figshare.com/articles/dataset/Duration_of_the_Early_Bajocian_and_the_associated_sup_13_sup_C_positive_excursion_based_on_cyclostratigraphy/3453146
<p>The Early Bajocian, about 172 Ma ago, was a period of tectonic changes, a global carbon-isotope positive excursion, and biological
diversification of marine invertebrates (e.g. ammonites, radiolarians and coccolithophores). Unfortunately, both the duration
of the Early Bajocian and the associated palaeoenvironmental changes are still poorly constrained. We propose here an estimate
of the duration of this sub-stage based on a cyclostratigraphic analysis of the carbonate content from the Chaudon–Norante
section, French Subalpine Basin, France. The Chaudon–Norante succession has been correlated with Les Dourbes section using
greyscale variations to detect possible local hiatuses. The duration estimated here for the entire Early Bajocian is 4.082
Ma. Two intervals were identified in the positive δ<sup>13</sup>C excursion: an increase of carbon isotope values lasting 1.36 Ma and climax isotope values lasting for 2.72 Ma. A cooling
at high latitudes and warming at low latitudes may have enhanced the Earth’s temperature gradient leading to an increase in
humidity, which in turn triggered ocean eutrophication at the origin of the δ<sup>13</sup>C positive excursion.
</p>