Fig. 1.

(adapted [1]): (a) General map presenting the main physiographic features between the Rivera and Orozco Fracture Zones (FZ), and the present study area location (red rectangle). (b) Bathymetry (40 m-grid spacing) of the study area showing the current axis (X) and two relic axes (Y and Z), the “Mudskipper Seamounts” chain, the “Split Seamount” on top of the axis, as well as two high-resolution sampling profiles (axial and transversal). The color code adopted for all samples refers to their “local” isotopic fingerprints. Pink: Ambient Mantle signature (AM); Blue: Mudskipper-type 1 signature (M1); Green: Mudskipper-type 2 signature (M2); Red: Enriched Mid-Ocean Ridge Basalts (E-MORB); Black: depleted Normal Mid-Ocean Ridge Basalt (N-MORB).