Sea‐water circulation on an oolite‐dominated carbonate system in an epeiric sea (Middle Jurassic, Switzerland)

Abstract

The Middle Jurassic Burgundy carbonate platform occupied a central part of the Central European Epeiric Sea during the Middle Jurassic. The facies architecture of the oolitic calcarenite bodies was affected by tidal currents on the platform and relative sea‐level changes. The δ13C‐values of inorganic carbonates, sampled in biostratigraphic‐defined intervals, do not match very well between closely spaced sections and, hence, are of restricted use for stratigraphic purposes. It appears that the platform interior might have been decoupled from the global carbon pool. Although deposited in a rapidly accumulating setting, the recorded isotope signatures might be affected by some local stratigraphic gaps. Nonetheless, the carbon isotope data imply lateral changes of the platform waters; these appear to be related to the position on the platform and to the sediment dispersal pattern, as evidenced by clay minerals. Adjacent to the eastern margin of the platform, detrital chlorite and illite occur in considerable proportions, both ascribed to a boreal source to the east and the north‐east. In contrast, smectite‐rich mixed‐layer clay mineral content increases significantly towards the platform interior, pointing to a delivery from the north‐west. All these data are suggestive of an overall clockwise current pattern in the Central European Epeiric Sea during the Middle Jurassic.

Carbon cycle history through the Middle Jurassic (Aalenian – Bathonian) of the Mecsek Mountains, Southern Hungary

“…Isotope values from these Northern Tethyan oolites (Wetzel et al 2013) do not show particularly positive values expected for aragonite oolites. Indeed textures indicate that these oolites were calcitic (Wetzel et al 2013) (i.e. a calcite sea sensu Sandberg 1983) and therefore this region exporting aragonite during this time appears unlikely.…”

“…The Bajocian was a time of widespread oolite formation along the Northern (and southern) Tethys margin (Wetzel et al 2013). Isotope values from these Northern Tethyan oolites (Wetzel et al 2013) do not show particularly positive values expected for aragonite oolites. Indeed textures indicate that these oolites were calcitic (Wetzel et al 2013) (i.e.…”

“…Major carbon-cycle perturbations in the Middle Jurassic are also recognised in terrestrial organic matter (fossil wood) (Hesselbo et al 2003). Although the excursions of the Middle Jurassic have received only modest attention, they occur on more than one continent and may thus serve for global correlation of strata (e.g., Wetzel et al 2013;Hönig & John 2015;Dzyuba et al 2017). The goal of this study is to examine Aalenian-Bathonian carbon isotope stratigraphy from Hungary for comparison.…”

Alpine sedimentology: An introduction and tribute to Albert Matter and Daniel Bernoulli

“…In a contribution to this special issue, Wetzel et al . () analyse preserved sedimentary structures, carbon isotope and clay‐mineral records in an oolitic carbonate succession of Bajocian and Bathonian age in the Jura Mountains and interpret a clockwise current pattern in this particular part of the southern European shelf for this time period. Morales et al .…”

Mineralogical-petrographical study of evaporites from Mali Kukor, Vranjkovići and Slane Stine quarry (Upper Permian evaporites from Dalmatia, Croatia)

“…Ancient epeiric evaporitic platforms (SHAW, 1964;IRWIN, 1965;WETZEL et al, 2013;ORTI et al, 2017) are huge areas of restricted stagnant circulation on the continental margins of seaways where extensive evaporite beds periodically accumulated (WARREN, 2006).…”