Seismic Insight on Basement Structure of the Extinct Mid‐Oceanic Ridge in Canada Basin, Arctic Ocean

The most accepted theory for the formation of the Canada Basin is that it was created during 66° rotation of Arctic Alaska around the Euler pole located near the Mackenzie Delta sometime during the Mesozoic. Gravity and magnetic anomaly data are consistent with an extinct mid‐oceanic ridge (MOR) in the central basin. This extinct MOR is critical to understand the development of the Canada Basin, but it is not well mapped due to ice conditions and is buried by thick sediment. The objective of this study is to map the ridge structure and gather all the available data to establish the role of the MOR in the history of the Amerasia Basin. We acquired multichannel seismic reflection (MCS) from RV Sikuliaq in 2021 across the Canada Basin between ∼75.5°N to 77°N. We combined our MCS data with the data collected in 2007–2011 from the IB Louis S. St. Laurent to generate a basement map of the Canada Basin. On MCS profiles, we observed the rugged axial topography of the inferred fossil spreading ridge. The MCS profiles parallel to this feature reveal the unsignificant broken basement morphology, which suggests that this ridge is not surely segmented by transform faults. The basement map is consistent with the continuous linear feature we interpret as an extinct MOR. The ridge morphology and tectonic setting are similar to the ultra‐slow spreading Gakkel Ridge. If so, assuming a 1–2 cm/yr spreading rate, forming a 300 km wide strip of oceanic crust in the central basin would require between 15 and 30 My.