Numerical modeling of thermal structure, circulation of H2O, and magmatism–metamorphism in subduction zones: Implications for evolution of arcs

Shallow-depth melt eduction due to ridge subduction: LA-ICPMS U-Pb igneous and detrital zircon ages from the Chile Triple Junction and the Taitao Peninsula, Chilean Patagonia

“…Our results also support a shallow melt eduction scenario that is predicted by numerical models (e.g., Iwamori, 2000;Iwamori et al, 2007;Maruyama and Okamoto, 2007). When slab melting occurs, as exemplified by Kon et al (2013), H 2 O and other volatiles are incorporated into the melts (Iwamori, 1998).…”

“…Several authors have suggested that ridge subduction is important for the genesis of large granite batholiths and/ or paired metamorphic belts (Iwamori, 2000;Iwamori et al, 2007;Aoya et al, 2009) because of its high heat flow (DeLong et al, 1979). It has been suggested that igneous rocks with adakitic compositions are a product of partial melting of a young and hot subducted slab under garnetamphibolite to eclogite conditions (Rapp et al, 1991;Defant and Drummond, 1990;Kay et al, 1993;Peacock et al, 1994;Drummond et al, 1996;Springer and Seck, 1997), and hence, are related to ridge subduction.…”

Occurrence of pockmarks on the Ortegal Spur continental margin, Northwestern Iberian Peninsula

“…Nevertheless, in the Ortegal Spur the subsidence during AptianAlbian rift episode was not enough to reach the oil window if normal geothermal gradient are considered. However, the southward subduction of the oceanic crust on the Cantabrian margin during the Tertiary (Sibuet and Le Pichon, 1971;Boillot et al, 1979;Grimaud et al, 1982) caused that the geothermal gradients resulting from shear heating within the subduction zone (Iwamori et al, 2007) were a sufficient overburden for the maturation of source-rocks and the generation of oil and/or deep thermogenic fluids. Taking into account the total organic carbon present in the Albian-Aptian deposits of the Basque-Cantabrian Basin, probably very similar that in the Ortegal Spur, and the geothermal gradient related with the subduction processes during the Cenozoic it can be assumed that the pockmarks were caused by thermogenic fluid migration from Late Cretaceous units in recent times.…”

Silicification of pelitic schist in the Ryoke low‐pressure/temperature metamorphic belt, Southwest Japan: Origin of competent layers in the middle crust

“…It is known that dehydration reactions from oceanic crust occurred in subduction zones (e.g. Peacock 1990; Iwamori et al. 2007).…”