Magma plumbing beneath Anak Krakatau volcano, Indonesia: evidence for multiple magma storage regions
2012 (English)In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 163, no 4, 631-651 p.Article in journal (Refereed) Published
Understanding magma plumbing is essential for predicting the behaviour of explosive volcanoes. We investigate magma plumbing at the highly active Anak Krakatau volcano (Indonesia), situated on the rim of the 1883 Krakatau caldera by employing a suite of thermobarometric models. These include clinopyroxene-melt thermobarometry, plagioclase-melt thermobarometry, clinopyroxene composition barometry and olivine-melt thermometry. Petrological studies have previously identified shallow magma storage in the region of 2–8 km beneath Krakatau, while existing seismic evidence points towards mid- to deep-crustal storage zone(s), at 9 and 22 km, respectively. Our results show that clinopyroxene in Anak Krakatau lavas crystallized at a depth of 7–12 km, while plagioclase records both shallow crustal (3–7 km) and sub-Moho (23–28 km) levels of crystallization. These magma storage regions coincide with well-constrained major lithological boundaries in the crust, implying that magma ascent and storage at Anak Krakatau is strongly controlled by crustal properties. A tandem seismic tomography survey independently identified a separate upper crustal (<7 km) and a lower to mid-crustal magma storage region (>7 km). Both petrological and seismic methods are sensitive in detecting magma bodies in the crust, but suffer from various limitations. Combined geophysical and petrological surveys, in turn, offer increased potential for a comprehensive characterization of magma plumbing at active volcanic complexes.
Place, publisher, year, edition, pages
2012. Vol. 163, no 4, 631-651 p.
Anak Krakatau, Thermobarometry, Clinopyroxene, Plagioclase, Magma plumbing, Seismic tomography
Earth and Related Environmental Sciences
Research subject Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
IdentifiersURN: urn:nbn:se:uu:diva-159368DOI: 10.1007/s00410-011-0690-8ISI: 000302373800004OAI: oai:DiVA.org:uu-159368DiVA: diva2:444512