seamount collision. These calcalkaline magmas are more
common where crust is thicker or the subducting plate is
younger.
Ore deposits
Island arcs host many economically important ore
deposits. For example, venting of high-temperature
hydrothermal fluids into ocean water by submarine arc
volcanoes causes Fe-Pb-Cu-Zn-Ag sulfides to precipitate
and accumulate as volcanogenic massive sulfide deposits
(Hannington 2014). Hydrothermal systems that are thermally and chemically driven by plutons associated with
continental andesitic to rhyolitic volcanic centers in
unusually compressional settings in produce the Cu and
Mo porphyry deposits that are the principal sources for
these and many other societally important metals (e.g.,
Richards and Mumin, 2013). Much of the world’s Au precipitated in shallower portions of arc magmatic systems
where hydrothermal fluids boil (e.g., Cook et al., 2011).
Summary
Terrestrial island arcs or volcanic arcs are regions up to
100 km wide of subaerial and submarine volcanoes whose
trenchward limit is ~120 km above the subducting plate.
Their magmas are more andesitic than elsewhere on Earth
or other planets and contribute to continent formation.
Their volcanoes are often explosive, and their magmatism
creates important metal ore deposits. There are 3-D variations in the spacing of volcanoes and the composition of
magmas both of which are related to the thermal structure
of the subducting plate and overlying convecting mantle.
Bibliography
Behn, M., Keleman, P., Hirth, G., Hacker, B., and Massone, H.,
2011. Diapirs as the source of the sediment signature in arc lavas.
Nature Geoscience, 4, 641–646.
Calvert, A. J., 2011. The seismic structure is island arc crust. In
Brown, D., and Ryan, P. (eds.), Arc-Continent Collision. New
York: Springer. Frontiers in Earth Sciences, pp. 87–119.
Cook, D. R., Deyell, C. L., Waters, P. J., Gonzales, R. I., and Zawi, K.,
2011. Evidence for magmatic-hydrothermal fluids and
ore-forming processes in epithermal and porphyry deposits of the
baguio district, Philippines. Economic Geology, 106, 1399–1424.
Cooper, L., Ruscitto, D., Plank, T., Wallace, P., Syracuse, E., and
Manning, C., 2012. Global variations in H 2 O/Ce: 1. Slab surface
temperatures beneath volcanic arcs. Geochemistry Geophysics
Geosystems, 13, Q03024, doi:10.1029/2011GC003902.
England, P., and Katz, R., 2010. Melting above the anhydrous solidus controls the location of volcanic arcs. Nature, 467, 700–703.
Frank, F., 1968. Curvature of island arcs. Nature, 220, 363.
Gill, J., 1981. Orogenic Andesites and Plate Tectonics. New York:
Springer, p. 390pp.
Hannington, M. D., 2014. Volcanogenic massive sulfide deposits.
In Treatise on Geochemistry, 2nd edn. Amsterdam: Elsevier,
Vol. 13, pp. 463–488.
Hochstaedter, A., Gill, J., Peters, R., Broughton, P., Holden, P., and
Taylor, B., 2001. Across-arc geochemical trends in the
Izu-Bonin arc: contributions from the subducting slab. Geophysics, Geochemistry, Geosystems, Paper No. 2000GC000105.
Honda, S., and Yoshida, T., 2005. Application of the model of
small-scale convection under the island arc to the NE Honshu
subduction zone. Geochemistry Geophysics Geosystems, 6,
Q01002, doi:10.1029/2004GC000785.
Ishizuka, O., Tani, K., Reagan, M., Kanayama, K., Umino, S.,
Harigane, Y., Sakamoto, I., Miyajima, Y., Yuasa, M., and
Dunkley, D., 2011. The timescales of subduction initiation and
subsequent evolution of an oceanic island arc. Earth and Planetary Science Letters, 306, 229–240.
Kimura, J.-I., Adam, J. R. K., Rowe, M., Nakano, N., Katakuse, M.,
van Keken, P., Hacker, B., and Stern, R. J., 2010. Origin of crosschain geochemical variation in Quaternary lavas from northern
Izu arc: a quantitative mass balance approach on source identification and mantle wedge processes. Geochemistry, Geophysics,
Geosystems, doi:10.1029/2010GC003050.
Kodaira, S., 2007. Seismological evidence for variable growth of continental crust in the Izu-Bonin intra-oceanic arc. Journal of Geophysical Research, 112, B05104, doi:10.1029/2006JB004593.
Marsh, B., and Carmichael, I.S.E., 1974. Benioff zone magmatism.
Journal of Geophysical Research, 79, 1196–1206.
Plank, T., 2005. Constraints from Thorium/Lanthanum on sediment
recycling at subduction zones and the evolution of continents.
Journal of Petrology, 46, 921–944.
Reagan, M., Ishizuka, O., Stern, R., Kelley, K., Ohara, Y., BlichertToft, J., Bloomer, S., Cash, J., Fryer, P., Hanan, B., HickeyVargas, R., Ishii, T., Kimura, J., Peate, D., Rowe, M., and Woods,
M., 2010. Fore-arc basalts and subduction initiation in the
Izu-Bonin-Mariana
system.
Geochemistry
Geophysics
Geosystems, 11, Q003X12, doi:10.1029/2009GC002871.
Richards, J. P., and Mumin, A. H., 2013. Magmatic-hydrothermal
processes within an evolving Earth: Iron oxide-copper-gold
and porphyry Cu Æ Mo Æ Au deposits. Geology, 41, 767–770,
doi:10.1130/G34275.1.
Syracuse, E., van Keken, P., and Abers, G., 2010. The global range
of subduction zones thermal models. Physics of the Earth and
Planetary Interiors, 51, 1761–1782.
Takahashi, N., Kodaira, S., Klemperer, S., Tatsumi, Y., Kaneda, Y.,
and Suyehiro, K., 2007. Crustal structure and evolution of the
Mariana intra-oceanic island arc. Geology, 35, 203–206.
Island Arc Volcanism, Volcanic Arcs, Figure 3 Th/La of the slabderived component in arc magmas compared to the Th/La ratio
of sediment subducting beneath the same arcs. See Plank (2005)
for details about both axes and the error bars.
382
ISLAND ARC VOLCANISM, VOLCANIC ARCS
common where crust is thicker or the subducting plate is
younger.
Ore deposits
Island arcs host many economically important ore
deposits. For example, venting of high-temperature
hydrothermal fluids into ocean water by submarine arc
volcanoes causes Fe-Pb-Cu-Zn-Ag sulfides to precipitate
and accumulate as volcanogenic massive sulfide deposits
(Hannington 2014). Hydrothermal systems that are thermally and chemically driven by plutons associated with
continental andesitic to rhyolitic volcanic centers in
unusually compressional settings in produce the Cu and
Mo porphyry deposits that are the principal sources for
these and many other societally important metals (e.g.,
Richards and Mumin, 2013). Much of the world’s Au precipitated in shallower portions of arc magmatic systems
where hydrothermal fluids boil (e.g., Cook et al., 2011).
Summary
Terrestrial island arcs or volcanic arcs are regions up to
100 km wide of subaerial and submarine volcanoes whose
trenchward limit is ~120 km above the subducting plate.
Their magmas are more andesitic than elsewhere on Earth
or other planets and contribute to continent formation.
Their volcanoes are often explosive, and their magmatism
creates important metal ore deposits. There are 3-D variations in the spacing of volcanoes and the composition of
magmas both of which are related to the thermal structure
of the subducting plate and overlying convecting mantle.
Bibliography
Behn, M., Keleman, P., Hirth, G., Hacker, B., and Massone, H.,
2011. Diapirs as the source of the sediment signature in arc lavas.
Nature Geoscience, 4, 641–646.
Calvert, A. J., 2011. The seismic structure is island arc crust. In
Brown, D., and Ryan, P. (eds.), Arc-Continent Collision. New
York: Springer. Frontiers in Earth Sciences, pp. 87–119.
Cook, D. R., Deyell, C. L., Waters, P. J., Gonzales, R. I., and Zawi, K.,
2011. Evidence for magmatic-hydrothermal fluids and
ore-forming processes in epithermal and porphyry deposits of the
baguio district, Philippines. Economic Geology, 106, 1399–1424.
Cooper, L., Ruscitto, D., Plank, T., Wallace, P., Syracuse, E., and
Manning, C., 2012. Global variations in H 2 O/Ce: 1. Slab surface
temperatures beneath volcanic arcs. Geochemistry Geophysics
Geosystems, 13, Q03024, doi:10.1029/2011GC003902.
England, P., and Katz, R., 2010. Melting above the anhydrous solidus controls the location of volcanic arcs. Nature, 467, 700–703.
Frank, F., 1968. Curvature of island arcs. Nature, 220, 363.
Gill, J., 1981. Orogenic Andesites and Plate Tectonics. New York:
Springer, p. 390pp.
Hannington, M. D., 2014. Volcanogenic massive sulfide deposits.
In Treatise on Geochemistry, 2nd edn. Amsterdam: Elsevier,
Vol. 13, pp. 463–488.
Hochstaedter, A., Gill, J., Peters, R., Broughton, P., Holden, P., and
Taylor, B., 2001. Across-arc geochemical trends in the
Izu-Bonin arc: contributions from the subducting slab. Geophysics, Geochemistry, Geosystems, Paper No. 2000GC000105.
Honda, S., and Yoshida, T., 2005. Application of the model of
small-scale convection under the island arc to the NE Honshu
subduction zone. Geochemistry Geophysics Geosystems, 6,
Q01002, doi:10.1029/2004GC000785.
Ishizuka, O., Tani, K., Reagan, M., Kanayama, K., Umino, S.,
Harigane, Y., Sakamoto, I., Miyajima, Y., Yuasa, M., and
Dunkley, D., 2011. The timescales of subduction initiation and
subsequent evolution of an oceanic island arc. Earth and Planetary Science Letters, 306, 229–240.
Kimura, J.-I., Adam, J. R. K., Rowe, M., Nakano, N., Katakuse, M.,
van Keken, P., Hacker, B., and Stern, R. J., 2010. Origin of crosschain geochemical variation in Quaternary lavas from northern
Izu arc: a quantitative mass balance approach on source identification and mantle wedge processes. Geochemistry, Geophysics,
Geosystems, doi:10.1029/2010GC003050.
Kodaira, S., 2007. Seismological evidence for variable growth of continental crust in the Izu-Bonin intra-oceanic arc. Journal of Geophysical Research, 112, B05104, doi:10.1029/2006JB004593.
Marsh, B., and Carmichael, I.S.E., 1974. Benioff zone magmatism.
Journal of Geophysical Research, 79, 1196–1206.
Plank, T., 2005. Constraints from Thorium/Lanthanum on sediment
recycling at subduction zones and the evolution of continents.
Journal of Petrology, 46, 921–944.
Reagan, M., Ishizuka, O., Stern, R., Kelley, K., Ohara, Y., BlichertToft, J., Bloomer, S., Cash, J., Fryer, P., Hanan, B., HickeyVargas, R., Ishii, T., Kimura, J., Peate, D., Rowe, M., and Woods,
M., 2010. Fore-arc basalts and subduction initiation in the
Izu-Bonin-Mariana
system.
Geochemistry
Geophysics
Geosystems, 11, Q003X12, doi:10.1029/2009GC002871.
Richards, J. P., and Mumin, A. H., 2013. Magmatic-hydrothermal
processes within an evolving Earth: Iron oxide-copper-gold
and porphyry Cu Æ Mo Æ Au deposits. Geology, 41, 767–770,
doi:10.1130/G34275.1.
Syracuse, E., van Keken, P., and Abers, G., 2010. The global range
of subduction zones thermal models. Physics of the Earth and
Planetary Interiors, 51, 1761–1782.
Takahashi, N., Kodaira, S., Klemperer, S., Tatsumi, Y., Kaneda, Y.,
and Suyehiro, K., 2007. Crustal structure and evolution of the
Mariana intra-oceanic island arc. Geology, 35, 203–206.
Island Arc Volcanism, Volcanic Arcs, Figure 3 Th/La of the slabderived component in arc magmas compared to the Th/La ratio
of sediment subducting beneath the same arcs. See Plank (2005)
for details about both axes and the error bars.
382
ISLAND ARC VOLCANISM, VOLCANIC ARCS