Cumulate xenolith in Oahu, Hawaii: implications for deep magma chambers and Hawaiian volcanism
Sen G and Jones RE. 1990. Cumulate xenolith in Oahu, Hawaii: implications for deep magma chambers and Hawaiian volcanism. Science. 249(4973):1154-1157
The maximum depth at which large (>1000 km3) terrestrial mafic magma chambers can form has generally been thought to be the Moho, which occurs at a mean depth of about 35 kilometers beneath the continents and 8 kilometers beneath ocean basins. However, the presence of layers of cumulus magnesium-rich spinel and olivine and intercumulus garnet in an unusual mantle xenolith from Oahu, Hawaii, suggests that this rock is a fragment of a large magma chamber that formed at a depth of about 90 kilometers; Hawaiian shield-building magmas may pond and fractionate in such magma chambers before continuing their ascent. This depth is at or near the base of the 90-million-year-old lithosphere beneath Oahu; thus, rejuvenated stage alkalic magmas containing mantle xenoliths evidently also originate below the lithosphere.
- Type
- Journal Article
- Authors
- Sen, G; Jones, R
- Units
- HAVO
- Keywords
- Cross-Section, Honolulu Volcanic Series, Magma Storage, Mantle, Mechanism, Oahu, Partial Melt, Rejuvenated Stage