Upper Quaternary Sedimentary and Oceanographic Processes at Bight Fracture Zone (North Atlantic Ocean)

• Main Authors: Copete, M.F., Pérez-Arlucea, Marta, Diz, Paula, Mena, Anxo, Estrada, Ferran, Alejo, Irene, Nombela, Miguel Ángel, Francés, Guillermo
• Other Authors: Ministerio de Ciencia, Innovación y Universidades (España)
• Format: Conference Object
• Language: English
• Published: 2022
• Subjects: Bight Fracture Zone; Pleistocene; Millennial climate and oceanographic oscillations; Las Palmas; Mid-Atlantic Ridge; Sarmiento; Iceland; North Atlantic; Subarctic
• Online Access: http://hdl.handle.net/10261/303597

VIII International Symposium on Marine Sciences, 6-8 July 2022, Las Palmas de Gran Canaria, España Charlie-Gibbs Fracture Zone (CGFZ) and Bight Fracture Zone (BFZ) are the main deep ocean passages crossing the Mid-Atlantic Ridge and connecting East and West North Atlantic basins. Iceland-Scotland Overflow Water (ISOW) travels through these narrow corridors, generating channel-related contourites. Currently, sedimentary processes linked to bottom currents, gravity flows from fault scarps, and pelagic-hemipelagic settling result in complex interactions. Upper Quaternary climate fluctuations complicate further these interactions. Acoustic (Atlas Hydrosweep DS) and seismic parametric (Atlas Parasound P-35) records obtained during the cruise BOCATS2-BFZ21 onboard B/O Sarmiento de Gamboa were used to develop a high-resolution bathymetry and obtain the geometry of several contourite bodies and other deposits. Four gravity cores were retrieved in selected points considering the seismic information. This work presents the first multiproxy results from the westernmost core, BFZ21-GC01 (4.80 m long; 57º 7.06N; 35º 16.354W; 2746 mbsl). The study includes sedimentary and tomographic facies, grain-size (bulk and free biogenic components), and textural and compositional analyses. Besides, several AMS14C dates and specific climatic/oceanographic events enable the development of an age model. The core spans from MIS4 to the present, recording the main North Atlantic climatic events (mainly Heinrich stadials, HS); conspicuous fluctuations in the analysed parameters and facies changes reveal millennial-scale oscillations of bottom currents activity, primary biological productivity and ice dynamics. Persistent advances and retreats of the Subarctic Front (SAF) are the most likely cause behind those high-frequency oscillations This work has been founded by the project Observación Bienal del carbono, acidificación, transporte y sedimentación en el Atlántico Norte (BOCATS2, Ref.: PID2019-104279GB-C22). Ministerio de Ciencia e ...