Physics – Geophysics
Scientific paper
Aug 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994e%26psl.126...15g&link_type=abstract
Earth and Planetary Science Letters (ISSN 0012-821X), vol. 126, no. 1-3, p. 15-22
Physics
Geophysics
9
Earth Crust, Geodynamics, Helium Isotopes, Olivine, Pyroxenes, Radioactive Contaminants, Volcanoes, Basalt, Geophysics, Indonesia, Melting, Planetary Evolution
Scientific paper
Helium isotope data have been obtained on well-characterised olivine and clinopyroxene phenocrysts and xenocrysts from thirteen volcanic centres located between central Sumatra and Sumbawa in the Sunda arc of Indonesia. Olivine crystals in mantle xenoliths (Iherzolite) from Bukit Telor basalts are primitive (Mg# = 90), and their He-3/He-4 value (R/R(sub A) = 8.8) indicates that the Sumatran mantle wedge is MORB-like in helium isotope composition. All other samples have lower He-3/He-4 ratios ranging from 8.5R(sub A) to 4.5R(sub A), with most (thirteen out of eighteen) following a trend of more radiogenic He-3/He-4 values with decreasing Mg#. The only exceptions to this trend are phenocrysts from Batur, Agung and Kerinci, which have MORB-like He-3/He-4 values but relatively low Mg# (Mg# = 70-71), and two highly inclusion-rich clinopyroxenes which have He-3/He-4 values lower than other samples of similar Mg#. The results indicate that crustal contamination unrelated to subduction in the Sunda arc is clearly recorded in the He-3/He-4 characteristics of mafic phenocrysts of subaerial volcanics, and that addition of radiogenic helium is related to low-pressure differentiation processes affecting the melts prior to eruption. These conclusions may have widespread applicability and indicate that helium isotope variations can act as an extremely sensitive tracer of upper crustal contamination.
Gasparon Massimo
Hilton David R.
Varne R.
No associations
LandOfFree
Crustal contamination processes traced by helium isotopes: Examples from the Sunda arc, Indonesia does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Crustal contamination processes traced by helium isotopes: Examples from the Sunda arc, Indonesia, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Crustal contamination processes traced by helium isotopes: Examples from the Sunda arc, Indonesia will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1495276