Construction and evolution of igneous bodies: Towards an integrated perspective of crustal magmatism

Catherine Annen*, Jonathan D. Blundy, Julien Leuthold, R. Stephen J Sparks

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

117 Citations (Scopus)

Abstract

Field, geochronological and geophysical studies show that many igneous bodies are emplaced incrementally, growing by accretion of successive magma sheets. The existence of melt reservoirs with a size that exceeds one single increment strongly depends on the sheet emplacement rate, whereas the total volumes of magma that accumulate depend on the volumetric magma flux. Integration of geochronological and field data with numerical simulations suggeststhat those rates can vary dramatically over the growth of an igneous body and that magmas accumulate to form melt-rich magma chambers only during episodes of high magma flux.Heat and mass balance considerations and the large volumes of mafic magma required to generate differentiated melts suggest that most crustal differentiation happens in deep hot zones in the lower crust wherein a wide diversity of melts are produced by crystallisation of mafic parents and concomitant partial melting of the crust. Melt composition is further modified during migration, segregation and ascent, and intermediate compositions can be generated when different types of melt mix. Magma fluxes and intrusion geometry play a fundamental role in igneous body evolution. Thus our knowledge of igneous processes depends ultimately on our understanding of the physics that control magma fluxes into the crust, magma emplacement within the crust and magma migration through the crust.

Original languageEnglish
Pages (from-to)206-221
Number of pages16
JournalLithos
Volume230
DOIs
Publication statusPublished - 1 Aug 2015

Keywords

  • Crustal differentiation
  • Igneous bodies
  • Incremental emplacement
  • Magma chambers
  • Magma fluxes
  • Melt reservoirs

Fingerprint Dive into the research topics of 'Construction and evolution of igneous bodies: Towards an integrated perspective of crustal magmatism'. Together they form a unique fingerprint.

Cite this