Azores-Biscay Rise and Bay of Biscay: A key area for the reconstruction of the geodynamic evolution of the early North Atlantic, 31.07.2021 – 29.08.2021, Emden (Germany) – Emden (Germany) - BISCAY CONNECTION (GPF 21-2_048)

• Main Authors: Geldmacher, Jörg, Werner, Reinhard
• Format: Report
• Language: English
• Published: Gutachterpanel Forschungsschiffe 2021
• Subjects: Charcot; Mid-Atlantic Ridge; North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/54527/; https://oceanrep.geomar.de/id/eprint/54527/1/M176%20Cruise%20Report.pdf; https://doi.org/10.48433/cr_m176

Understanding the opening of the Bay of Biscay and the associated kinematics of the Iberian plate during the late Cretaceous is fundamental for reconstructing the opening and evolution of the North Atlantic Ocean. A key region for unraveling the opening history of the Atlantic Ocean basin is the intersection of the former Biscay spreading axis with the early Mid-Atlantic Ridge, offshore of the NW corner of present-day Iberia. At this site, the intersection merges with the ~750 km long Azores-Biscay Rise, a prominent feature in the East Atlantic of unknown origin. Models for the origin of the Azores-Biscay Riserange from formation as intraplate hotspot track to shallow tectonic causes. The R/V METEOR expedition M176 conducted multi-beam mapping and hard rocksampling of the following structures: 1) Charcot and La Coruña seamount complexes (the presumed former Biscay spreading center), 2) seamounts north of the Azores-Biscay Rise, and 3) the entire Azores-Biscay Rise. Despite technical challenges, 78 dredge hauls were carried out and 2,404 nm were swath-mapped. Age determinations and geochemical investigations of the recovered rock samples will allow us to test the different models regarding the opening of the Bay of Biscay and the origin of the Azores-Biscay Riseas well as the possible role of a mantle plume in this area during the opening of the North Atlantic.