Faulting and Magmatic Accretion Across the Overlapping Spreading Center Between Vance Segment and Axial South Rift, Juan de Fuca Ridge

Plate divergence along mid-ocean ridges is accommodated through faulting and magmatic accretion, and, at overlapping spreading centers (OSC), distributed across two curvilinear ridge axes. One-meter resolution bathymetry acquired by autonomous underwater vehicles, combined with distribution ages of lava flows, used to: (a) analyze the spatial temporal faults, fissures in OSC between distal south rift zone Axial Seamount Vance Segment, (b) locate axes, (c) calculate extension, (d) determine proportion extension surface faults versus volcanic extrusion over a period ∼1300–1450 years. Our study reveals that recent history ridges, distance 14 km Axial/Vance was asymmetric style: 1–2 axial valley ∼3/4 spreading, whereas dike-fed eruptions contributed ∼1/4 occurred 4 Seamount.