On the importance of crystallization-differentiation for the generation of SiO2-rich melts and the compositional build-up of arc (and continental) crust

  title={On the importance of crystallization-differentiation for the generation of SiO2-rich melts and the compositional build-up of arc (and continental) crust},
  author={Oliver Jagoutz and Benjamin Z. Klein},
  journal={American Journal of Science},
  pages={29 - 63}
In this paper we review processes responsible for the formation of granites in subduction systems. While there is robust evidence that strongly peraluminous, so-called S-type granites are formed by melting of metasediments in the (lower) crust, the processes that form metaluminous, so-called I-Type granites are less certain. We review four lines of evidence that have been presented in support of a dominantly crustal origin for these granites: 1) field observations; 2) isotopic compositions; 3… 

Do arc silicic magmas form by fluid-fluxed melting of older arc crust or fractionation of basaltic magmas?

Under the right circumstances, fluid-fluxed crustal melting occurs, as demonstrated by some amphibolite-facies migmatites, but the relatively low temperatures involved make this mode of formation an

Geochemical evidence for the production of granitoids through reworking of the juvenile mafic arc crust in the Gangdese orogen, southern Tibet

Although continental crust is characterized by the widespread occurrence of granitoids, the causal relationship between continental crust growth and granitic magmatism still remains enigmatic.

Granites and crustal heat budget

Abstract The origin of large I-type batholiths remains a disputed topic. One model states that I-type granites form by partial melting of older crustal lithologies (amphibolites or intermediate

Evidence for polybaric fractional crystallization in a continental arc: Hidden Lakes mafic complex, Sierra Nevada batholith, California

Although the voluminous granitoids that constitute the upper crust of the Sierra Nevada batholith (California) have been investigated in detail, comparatively few studies focus on the origin of mafic



The trace element compositions of S-type granites: evidence for disequilibrium melting and accessory phase entrainment in the source

Within individual plutons, the trace element concentrations in S-type granites generally increase with maficity (total iron and magnesium content and expressed as atomic Fe + Mg in this study); the

Towards a unified model for granite genesis

  • B. Chappell
  • Geology
    Earth and Environmental Science Transactions of the Royal Society of Edinburgh
  • 2004
ABSTRACT Most granites result from partial melting within the crust. Granite melts produced at the lowest temperatures of partial melting mainly comprise close to equal amounts of the haplogranite

Constraints on melting and magma production in the crust

Mass transfer in the lower crust: Evidence for incipient melt assisted flow along grain boundaries in the deep arc granulites of Fiordland, New Zealand

Knowledge of mass transfer is critical in improving our understanding of crustal evolution, however mass transfer mechanisms are debated, especially in arc environments. The Pembroke Granulite is a

The role of an H2O-rich fluid component in the generation of primitive basaltic andesites and andesites from the Mt. Shasta region, N California

Abstract. This paper presents analyses of the trace element abundances and isotopic compositions in primitive lavas from the Mt. Shasta region, N California. These data are combined with estimates of

A dearth of intermediate melts at subduction zone volcanoes and the petrogenesis of arc andesites

It is argued that true liquids of intermediate composition are far less common in the sub-volcanic reservoirs of arc volcanoes than is suggested by the abundance of erupted magma within this compositional range.

Construction of the granitoid crust of an island arc part I: geochronological and geochemical constraints from the plutonic Kohistan (NW Pakistan)

We present major and trace element analyses and U–Pb zircon intrusion ages from I-type granitoids sampled along a crustal transect in the vicinity of the Chilas gabbronorite of the Kohistan