Water discharge variations control fluvial stratigraphic architecture in the Middle Eocene Escanilla formation, Spain - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue (Article De Synthèse) Scientific Reports Année : 2023

Water discharge variations control fluvial stratigraphic architecture in the Middle Eocene Escanilla formation, Spain

Résumé

Ancient fluvial deposits typically display repetitive changes in their depositional architecture such as alternating intervals of coarse-grained highly amalgamated (HA), laterally-stacked, channel bodies, and finer-grained less amalgamated (LA), vertically-stacked, channels encased in floodplain deposits. Such patterns are usually ascribed to slower, respectively higher, rates of base level rise (accommodation). However, "upstream" factors such as water discharge and sediment flux also play a potential role in determining stratigraphic architecture, yet this possibility has never been tested despite the recent advances in the field of palaeohydraulic reconstructions from fluvial accumulations. Here, we chronicle riverbed gradient evolution within three Middle Eocene (~ 40 Ma) fluvial HA-LA sequences in the Escanilla Formation in the south-Pyrenean foreland basin. This work documents, for the first time in a fossil fluvial system, how the ancient riverbed systematically evolved from lower slopes in coarser-grained HA intervals, and higher slopes in finer-grained LA intervals, suggesting that bed slope changes were determined primarily by climate-controlled water discharge variations rather than base level changes as often hypothesized. This highlights the important connection between climate and landscape evolution and has fundamental implications for our ability to reconstruct ancient hydroclimates from the interpretation of fluvial sedimentary sequences.

Domaines

Stratigraphie
Fichier principal
Vignette du fichier
sharma-2023.pdf (5.72 Mo) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Licence : CC BY - Paternité

Dates et versions

insu-04086830 , version 1 (02-05-2023)

Licence

Paternité

Identifiants

Citer

Nikhil Sharma, Alexander C Whittaker, Stephen E Watkins, Luis Valero, Jean Vérité, et al.. Water discharge variations control fluvial stratigraphic architecture in the Middle Eocene Escanilla formation, Spain. Scientific Reports, 2023, 13, pp.6834. ⟨10.1038/s41598-023-33600-6⟩. ⟨insu-04086830⟩
76 Consultations
19 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More