Carbon isotope stratigraphy, biostratigraphy and sedimentology of the Upper Jurassic – Lower Cretaceous Rayda Formation, Central Oman Mountains
Celestino, Ricardo; Wohlwend, Stephan; Reháková, Daniela; Weissert, Helmut
published: Jan 1, 2017
ArtNo. ESP026005001004, Price: 29.00 €
Carbon isotope chemostratigraphy and calpionellid biostratigraphy were used in this study to improve the stratigraphic resolution of the Upper Jurassic – Lower Cretaceous Rayda Formation and examine the expression of the Valanginian C-isotope event in the SE-Tethys. This integrated stratigraphic framework allows for a better correlation between south-eastern and western Tethys records and to obtain a better understanding of the oceanographic system on a regional scale. During the Late Jurassic, a major transgression induced a fast flooding of the Arabian Platform and lead to the deposition of the Rayda Formation. Red crinoidal limestones and submarine hardgrounds at the base of the formation are signs of condensed sedimentation influenced by changing current systems along the passive margin shelf. The following deposition of Maiolicatype micritic limestones with chert nodules recorded the establishment of pelagic conditions which presumed during the earliest Cretaceous and ended with the onset of the hemipelagic sediments of the Salil Formation. The upper part of the Rayda Formation, so far considered as Berriasian-earliest Valanginian in age, is here ascribed to the Upper Valanginian. The established δ13 C-curve records the distinct Valanginian C-isotope event (CIE) in the uppermost part of the Rayda Formation and the lowermost part of the Salil Formation. The age of the excursion is underpinned by calpionellid biostratigraphy.