Fig.1 Structural schematic diagram of the IBM intra-oceanic arc system, which transitioned into a subduction zone along a north-south transform fault during the Late Eocene (~42 Ma). Adapted from [4].

Fig.2 The profiles of crust and upper mantle perpendicular to the transform fault/oceanic trench, representing the tectonic structures before (A) and after (B) the initiation of IBM intra-oceanic arc subduction. C represents the geological relationship at the junction between the old oceanic crust-upper mantle and the infant arc oceanic crust-upper mantle. Adapted from [4].

Fig.3 The profile perpendicular to the infant arc of IBM. Adapted from [4].

Fig.4 The schematic diagram of Late Jurassic ophiolite and related rocks in Northwest California. Adapted from [4].

Fig.5 Comparison among before the infant arc, infant arc and mature arc of the Mariana-Bonin and California systems. Adapted from [4].

Fig.6 Comparison of stratigraphic profiles between IBM fore-arc lithosphere and Troodos (Cyprus) and Semail (Oman) ophiolites. Adapted from [7].

Fig.7 Overview of the subduction convergence system between the Nazca oceanic plate and the South American continental plate. Adapted from [8].

Fig.8 Experiment 1: the oceanic plate carrying an oceanic plateau subducts into the free overriding plat. Adapted from [8].

Fig.9 Experiment 4: Simulation experiment on subduction of an upper plate advancing towards the ocean trench via a piston mechanism. Adapted from [8].

Fig.10 Schematic sketches showing evolution of the flat slab subduction process illustrated by analog models, applied to the Andean subduction zone. Adapted from [8].

Fig.11 Thermal simulation of flat-slab subduction. Adapted from [11].

Fig.12 Three-stage evolution( from steep to flat subduction ) and arc magmatism due to subduction of buoyant, overthickened oceanic crust. Adapted from [11].

Fig.13 Slab window formed by orthogonal intersection between a spreading ridge and a trench. Adapted from [13].

Fig.14 Slab window formed by orthogonal subduction of segmented ridge-transform systems. Adapted from [13].

Fig.15 Effects of slab dip angle on slab window produced by orthogohal intersection between ridge and trench. Adapted from [13].

Fig.16 Formation of composite slab window when ridge and trench intersect obliquely,by different slab dip angles. Adapted from [13].

Fig.17 Slab window and magmatism between slabs of different dip angles. Adapted from [13].

Fig.18 Possible magmatic effects from migration of a slab window formed by subduction of an active ridge relative oblique to an oceanic trench. Adapted from [13].

Fig.19 Regional simple map of Chile Triple Junction. Adapted from [14].

Fig.20 Neogene-Quaternary near-trench magmatic activity associated with subduction of the active Chile Mid-Ocean Ridge. Adapted from [14].

Fig.21 Comparison of felsic volcanic rocks from Taitao peninsula, Taitao ridge, SSVZ and AVZ (type 5 and 6 in Table 1). Adapted from [14].

Fig.22 Evolution model of ridge-trench interaction caused by subduction of the Chile active ridge. Adapted from [15].

Fig.23 Tectonic discrimination diagram for alkali plateau basalts of South Patagonian. Adapted from [17].

Fig.24 Distribution map of alkaline plateau basalts of Patagonian and foreland fold-thrust belts. Adapted from [17].

Fig.25 Diagram between subducted oceanic lithosphere age and Y/Yb contents in arc volcanic rocks. Adapted from [23].

Fig.26 Diagram of Sr/Y-Y. Adapted from [23].

Fig.27 Diagrams of Nb/La-MgO(A) and Nb/U-Nb(B). Adapted from [29].

Fig.28 p-T (pressure-temperature) phase diagram for partial melting of basaltic rocks. Adapted from [19].

Fig.29 Tectonic model of thermo simulation of oceanic subduction zones. Adapted from [19].

Fig.30 Thermal structure derived from thermal simulation of subducting oceanic slabs with varying ages. Adapted from [19].

Fig.31 Scale-constrainted formation model of Elder Creek TTD suite. Adapted from [31].