Stepwise accumulation and ascent of magmas

P. D. Bons, J. Dougherty-Page, M. A. Elburg

Research output: Contribution to journalArticlepeer-review

73 Citations (Scopus)


One of the currently popular theories on magma ascent is that it mainly occurs by propagating hydrofractures (dykes) and that magma viscosity is the primary rate-controlling factor. This theory is based on mathematical models for single hydrofractures under idealised conditions. We simulated magma ascent with air ascending through gelatine and observed that the air ascended in batches, following paths made by their predecessors. Multiple batches accumulate at obstacles along the path. Although magma viscosity may control ascent rate during movement, obstacles ultimately control the size and average ascent velocity of ascending batches. We propose that step-wise movement of magma batches is the mechanism of primary accumulation and ascent from the partially molten source rock of a magma to its first emplacement site and therefore the main ascent mechanism for granitic magmas. 'Classical' dyking is the mechanism for secondary ascent from a magma chamber.

Original languageEnglish
Pages (from-to)627-633
Number of pages7
JournalJournal of Metamorphic Geology
Issue number5
Publication statusPublished - 2001
Externally publishedYes


  • Dykes
  • Magma accumulation
  • Magma ascent
  • Magma batches

ASJC Scopus subject areas

  • Geology
  • Geochemistry and Petrology


Dive into the research topics of 'Stepwise accumulation and ascent of magmas'. Together they form a unique fingerprint.

Cite this