Stable isotope compositions and water contents of boninite series volcanic rocks from Chichi-jima, Bonin Islands, Japan
Measurements of stable isotope compositions and water contents of boninite series volcanic rocks from the island of Chichi-jima, Bonin Islands, Japan, confirm that a large amount (1.6–2.4 wt.%) of primary water was present in these unusual magmas. An enrichment of 0.6‰ in18O during differentiation is explained by crystallization of18O-depleted mafic phases. Silicic glasses have elevated δ18O values and relatively low δD values indicating that they were modified by low-temperature alteration and hydration processes. Mafic glasses, on the other hand, have for the most part retained their primary isotopic signatures since Eocene time. Primary δD values of −53 for boninite glasses are higher than those of MORB and suggest that the water was derived from subducted oceanic lithosphere.
Citation Information
Publication Year | 1987 |
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Title | Stable isotope compositions and water contents of boninite series volcanic rocks from Chichi-jima, Bonin Islands, Japan |
DOI | 10.1016/0012-821X(87)90108-7 |
Authors | P.F. Dobson, J. R. O'Neil |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Earth and Planetary Science Letters |
Index ID | 70015237 |
Record Source | USGS Publications Warehouse |