Geology of the Charlie Gibbs transform system (52-53ºN, Mid Atlantic Ridge): preliminary results from Akademik Nikolaj Strakhov Expedition S50

The Charlie Gibbs offsetting by ~340 km the Mid Atlantic Ridge (MAR) axis between 52°-53° N is one of the main transform systems of the North Atlantic. Located between long mid-ocean ridge segments influenced to the south by the Azores and to the north by the Iceland mantle plume, this transform system has been active since the early phases of North Atlantic rifting. Object of several surveys in the ‘70 and ‘80, Charlie Gibbs received great attention for its unique structure characterized by two long-lived right-lateral transform faults linked by a short ~40 km-long intra-transform spreading centre (ITR) with parallel fracture zone valleys extending continuously towards the continental margins. In October 2020 expedition S50 of the R/V A.N. Strakhov surveyed an area of 54552 km² covering the entire Charlie Gibbs transform system and the adjacent MAR spreading segments. We collected new bathymetric, magnetic and high-resolution single channel seismic data, along with basaltic, gabbroic and mantle rocks from 21 dredges. In this contribution we present preliminary data from cruise S50 and discusses the large-scale architecture of this unique, long-lived transform system.