The Halimedides record in the Asturian Basin (northern Spain); supporting the Toarcian oceanic anoxic event relationship
The Halimedides record in the Asturian Basin (northern Spain); supporting the Toarcian oceanic anoxic event relationship (in Carbon cycle and ecosystem response to the Jenkyns event in the early Toarcian (Jurassic), M. Reolid (editor), L. V. Duarte (editor), E. Mattioli (editor) and W. Ruebsam (editor))
Special Publication - Geological Society of London (May 2021) 514 (1): 173-184
- Aptian
- assemblages
- Asturias Spain
- biostratigraphy
- black shale
- clastic rocks
- Cretaceous
- depositional environment
- Europe
- facies
- Iberian Peninsula
- ichnofacies
- ichnofossils
- Jurassic
- lithofacies
- Lower Cretaceous
- Lower Jurassic
- Mesozoic
- morphometry
- OAE 2
- oceanic anoxic events
- paleoenvironment
- sedimentary rocks
- Southern Europe
- Spain
- Toarcian
- Upper Cretaceous
- Asturian Basin
- OAE 1a
- Rodiles Spain
- Halimedides
- Lastres Spain
Recent ichnological analysis conducted in two sections (Rodiles and Lastres) of the Asturian Basin revealed the presence of Halimedides Lorenz von Liburnau 1902, which occurs just above the black shales related to the end of the Toarcian Oceanic Anoxic Event (T-OAE). Halimedides is associated with recovery of the trace-maker community after the re-establishment of favourable, oxic, conditions. The appearance of Halimedides after the T-OAE event, previously not registered, supports the close relationship of the trace maker with oxygen conditions, as occurs in other anoxic events including the Cretaceous OAE-1a and OAE-2. Also, a relationship between morphometric and palaeoenvironmental parameters is observed: occurring larger and densely chambered specimens in darker, weakly oxygenated facies, while smaller and sparsely chambered forms are registered in lighter, better oxygenated sediments.
