EGU22-7217, updated on 17 Nov 2022
https://doi.org/10.5194/egusphere-egu22-7217
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Seafloor spreading modes across the Charlie Gibbs transform system (52°N, Mid Atlantic Ridge)

Alessio Sanfilippo1, Sergey Skolotnev2, Marco Ligi3, Alexander Peyve1, and the A.N. Strakhov Expedition S50 and A.N. Vavilov Expedition V53 Science Parties*
Alessio Sanfilippo et al.
  • 1Dipartimento di Scienze della Terra e dell’Ambiente, Universita’ di Pavia, via Ferrata 1, 27100, Pavia, Italy (alessio.sanfilippo@unipv.it)
  • 2Geological Institute, Russian Academy of Sciences, Pyzhevskii per. 7, 119017 Moscow, Russia
  • 3Istituto di Scienze Marine – CNR, Bologna, via Gobetti 101, 40129 Bologna, Italy
  • *A full list of authors appears at the end of the abstract

The prominent Charlie Gibbs right-lateral multi-transform system (52°-53°N) offsets the Mid Atlantic Ridge (MAR) by ~340 km. The transform system is formed by two distinct transform faults linked by a short ~40 km-long intra-transform spreading centre (ITR). The two adjacent MAR segments are influenced by both the Azores and the Iceland mantle plume. Recently, high resolution multibeam surveys and a dense sampling program of the entire transform system, including the adjacent southern and northern MAR segments, were carried out during expeditions of R/V Celtic Explorer (2015, 2016 and 2018) [1], R/V A.N. Strakhov (2020) and A.S. Vavilov (2021) [2]. The new surveys show widespread occurrence of large structures with corrugated surfaces and exhumed lower crust and mantle rocks on both sides of the intra-transform spreading axis. Morphological analyses of the intra-transform domain and magnetic data indicate that crustal accretion was driven by flip-flop detachment faulting [3], with minimal ridge melt supply and little axial volcanism. The tectonic spreading persisted for tens of millions of years. Along axis MORB chemistry shows that changes in seafloor accretion styles are mirrored by variations in melt supply, in turn dependent on mantle temperature and by a large-scale mantle heterogeneity. Charlie Gibbs is a key case study of how seafloor accretion modes at a spreading segment is critically dependent on mantle thermal state but also on its intrinsic compositional heterogeneity.

[1] Georgiopoulou A. and CE18008 Scientific Party, 2018. Tectonic Ocean Spreading at the Charlie-Gibbs Fracture Zone (TOSCA): CE18008 Research Survey Report. Marine Institute of Ireland, Dublin, pp 1-24. [2] Skolotnev, S. et al., 2021. Seafloor Spreading and Tectonics at the Charlie Gibbs Transform System (52-53ºN, Mid Atlantic Ridge): Preliminary Results from R/V AN Strakhov Expedition S50. Ofioliti, 46(1). [3] Cannat, Met al., 2019. On spreading modes and magma supply at slow and ultraslow mid-ocean ridges. Earth and Planetary Science Letters, 519, 223-233.

A.N. Strakhov Expedition S50 and A.N. Vavilov Expedition V53 Science Parties:

Sergey G. Skolotnev, Marco Ligi, Alessio Sanfilippo, Alexander A. Peyve, Yago Nestola, Sergey Yu. Sokolov, Lorenzo Petracchini, Kseniya O. Dobrolyubova, Valentin Basch, Alexey N. Pertsev, Carlotta Ferrando, Alexander N. Ivanenko, Camilla Sani, Anatoly, A. Razumovskiy, Filippo Muccini, Artem S. Bich, Camilla Palmiotto, Yuri V. Brusilovsky, Enrico Bonatti, Konstantin N. Sholukhov, Marco Cuffaro, Ilya A. Veklich, Vitaly N. Dobrolyubov, Ekaterina P. Ponomarenkob, Dmitry A. Kuleshovc, Nikolay A. Shkittin, Tatyana L. Pugachevad, Svetlana A. Dokashenkoe, Elizaveta S. Yakovenkoe, Pavel A. Gladkich

How to cite: Sanfilippo, A., Skolotnev, S., Ligi, M., and Peyve, A. and the A.N. Strakhov Expedition S50 and A.N. Vavilov Expedition V53 Science Parties: Seafloor spreading modes across the Charlie Gibbs transform system (52°N, Mid Atlantic Ridge), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7217, https://doi.org/10.5194/egusphere-egu22-7217, 2022.