Origin and Geodynamic Evolution of King’s Trough – the Grand Canyon of the North Atlantic
Final Report Abstract
The project “Origin and Geodynamic Evolution of King’s Trough - the Grand Canyon of the North Atlantic” dealt with the King’s Trough, a huge canyon-like structure on the eastern North Atlantic seafloor, which together with the Peake and Freen Deeps forms the approximately 500 km long King’s Trough Complex. During RV METEOR cruise M168, the complex and the nearby Gnitsevich Seamounts were partly mapped, and magmatic rocks were recovered by dredging. Thereafter, a number of these samples were geochemically analyzed and age-dated in order to gain more insights into the origin and formation processes of these structures. The new data show that the prominent ridge-like structures flanking the King’s Trough as well as the Gnitsevich Seamounts predominantly have enriched geochemical compositions similar to the Azores Archipelago located to the south and that they formed on very young oceanic crust by excess volcanism near the Mid-Atlantic Ridge. The King’s Trough is embedded in thickened oceanic crust, which extends plateau-like on both sides of the Mid- Atlantic Ridge and shows a similarly enriched geochemical signature, whereas the Peake and Freen Deeps cut into normal oceanic crust outside of the plateau and the recovered samples have geochemically depleted mid-ocean ridge basalt (MORB) type compositions. This indicates that the plateau-like seafloor as well as the ridge-like structures along the King’s Trough and the seamounts distributed on the plateau were created under the influence of a mantle plume still located beneath the Mid-Atlantic Ridge at about 45°N and active since 53- 55 million years ago. A combination of the new geochemical, geochronological and bathymetric data with published magnetic data from the seafloor and plate reconstructions suggests that the King’s Trough Complex formed by oblique rifting along a temporary plate boundary between about 37 and 23 million years ago, and that the 45°N mantle plume represents one branch of the Azores plume. After the plate boundary had jumped to the Azores region around 23 million years ago, the main plume activity also shifted and further formation of the King's Trough ceased.
Publications
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Origin and Geodynamic Evolution of King's Trough: The Grand Canyon of the North Atlantic, Cruise No. M168 (GPF 20-3_080), November 08 - December 08, 2020, Emden (Germany) - Emden (Germany). METEOR-Berichte, M168. Gutachterpanel Forschungsschiffe, Bonn, Germany, 139 pp.
Dürkefälden, A., Geldmacher, J., Hauff, F. & Werner, R.
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Continuous thermosalinograph oceanography along RV METEOR cruise M168. PANGAEA.
Dürkefälden, A. & Schlundt, M.
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Multibeam bathymetry raw data (Kongsberg EM 122 transit dataset) of RV METEOR during cruise M168. PANGAEA.
Dürkefälden, A. & Wölfl, A.-C.
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Multibeam bathymetry raw data (Kongsberg EM 122 working area dataset) of RV METEOR during cruise M168. PANGAEA
Dürkefälden, A. & Wölfl, A.-C.
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Magmatic and geodynamic evolution of the King’s Trough Complex – The Grand Canyon of the North Atlantic. Goldschmidt2023 abstracts. European Association of Geochemistry.
Dürkefälden, Antje; Geldmacher, Jörg; Hauff, Folkmar; Garbe-Schönberg, Dieter; Portnyagin, Maxim; Schenk, Johanna; Stipp, Michael & Hoernle, Kaj
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Magmatic and geodynamic evolution of the King’s Trough Complex – The “Grand Canyon” of the North Atlantic (Poster) In: GeoBerlin 2023, 03.-07.09.2023, Berlin, Germany
Dürkefälden, A., Geldmacher, J., Hauff, F., Garbe-Schönberg, D., Portnyagin, M., Schenk, J., Stipp M. & Hoernle, K.
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The King’s Trough Complex: magmatic and geodynamic evolution of the Grand Canyon of the North Atlantic (Talk) In: Oceanic Volcanism Workshop 2023, 12.-15.09.2023, Kiel, Germany
Dürkefälden, A., Geldmacher, J., Hauff, F., Garbe-Schönberg, D., Portnyagin, M., Schenk, J., Stipp M. & Hoernle, K.
