For over a century, it has been assumed that magma is primarily stored in the Earth’s crust in large holes termed ‘magma chambers’. However, geophysical data have failed to image large, liquid-filled magma chambers even beneath active volcanoes, and geochemical and petrological data suggest that many magmas are stored in cool ‘mush reservoirs’ (closely packed crystals with melt present in the pore-space) until shortly before eruption.
The NORMS group uses numerical modelling to understand how chemical evolution occurs in these crustal mush reservoirs and how melt can rapidly accumulate prior to eruption. The models are constrained by geophysical, geochemical and petrological data from modern and ancient igneous systems. We collaborate closely with other academic institutions through, for example, membership of the FAMOS (From Arc Magma to Ore Bodies) project. Our research is also closely linked with the Imperial Centre for Geohazards and the Geophysics group at Imperial College London.
Pictured far left, Prof. Sir Steve Sparks (Bristol) leads a field trip on the island of Rum, Scotland, studying an ancient magma reservoir now exposed at the surface.
Left, magma in the active Kilauea volcano on Hawaii, pictured from the air.
Selected references
Sparks RSJ, Blundy JD, Cashman K, et al., 2022, Large silicic magma bodies and very large magnitude explosive eruptions, BULLETIN OF VOLCANOLOGY, Vol: 84, ISSN: 0258-8900
Edmonds M, Cashman KV, Holness M, et al., 2019, Architecture and dynamics of magma reservoirs, PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 377, ISSN: 1364-503X
Sparks RSJ, Annen C, Blundy JD, et al., 2019, Formation and dynamics of magma reservoirs, PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 377, ISSN: 1364-503X
Jackson MD, Blundy J, Sparks RSJ, 2018, Chemical differentiation, cold storage and remobilization of magma in the Earth's crust, Nature, Vol: 564, Pages: 405-409+, ISSN: 0028-0836
Solano JMS, Jackson MD, Sparks RSJ, et al., 2014, Evolution of major and trace element composition during melt migration through crystalline mush: Implications for chemical differentiation in the crust, American Journal of Science, Vol: 314, Pages: 895-939, ISSN: 0002-9599
Solano JMS, Jackson MD, Sparks RSJ, et al., 2012, Melt Segregation in Deep Crustal Hot Zones: a Mechanism for Chemical Differentiation, Crustal Assimilation and the Formation of Evolved Magmas, Journal of Petrology, Vol: 53, Pages: 1999-2026, ISSN: 1460-2415
Getsinger A, Rushmer T, Jackson MD, et al., 2009, Generating High Mg-numbers and Chemical Diversity in Tonalite-Trondhjemite-Granodiorite (TTG) Magmas during Melting and Melt Segregation in the Continental Crust, JOURNAL OF PETROLOGY, Vol: 50, Pages: 1935-1954, ISSN: 0022-3530
Rushmer T, Jackson MD, 2006, Impact of melt segregation on tonalite-trondhjemite-granodiorite (TTG) petrogenesis, TRANSACTIONS OF THE ROYAL SOCIETY OF EDINBURGH-EARTH SCIENCES, Vol: 97, Pages: 325-336, ISSN: 0263-5933
Jackson MD, Gallagher K, Petford N, et al., 2005, Towards a coupled physical and chemical model for tonalite–trondhjemite–granodiorite magma formation, Lithos, Vol: 79, Pages: 43-60
Jackson MD, Cheadle MJ, Atherton MP, 2003, Quantitative modeling of granitic melt generation and segregation in the continental crust, JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 108, ISSN: 2169-9313