The isotopic composition of postshield lavas from Mauna Kea volcano, Hawaii
- Author:
-
Kennedy, A.K., Kwon, S.-T., Frey, F.A., West, H.B.
- Title:
- The isotopic composition of postshield lavas from Mauna Kea volcano, Hawaii
- Periodical:
- Earth and Planetary Science Letters
- Year:
- 1991
- Volume:
- 103
- Pages:
- 339-353.
- Subject:
-
Mauna Kea volcano
Isotopes
Basalt
Lava
Radioactive dating
- Summary:
- The postshield eruptive stage of Mauna Kea volcano, Hawaii, can be divided into an early basaltic substage, the Hamakua Volcanics, and a hawaiite substage, the Laupahoehoe Volcanics. Cumulate gabbroic xenoliths in Laupahoehoe Volcanics have isotopic ratios similar to the Hamakua Volcanics, and these gabbros provide constraints on the crustal evolution of Mauna Kea lavas. Lavas from both substages contain relatively fixed proportions of depleted, enriched and primitive mantle components. In addition, there is Sr, Nd and Pb isotopic overlap between tholeiitic and alkalic Hamakua basalts. Lavas erupted during the postshield stage of Mauna Kea volcano do not define a systematic temporal trend of varying (super 87)Sr/(super 86)Sr and (super 143)Nd/(super 144)Nd. This result contrasts with the temporal trend defined by lavas from Haleakala Volcano and provides evidence for important differences between the origin and evolution of different Hawaiian volcanoes. Postshield lavas from Mauna Kea have relatively high Ce/Pb (40 plus or minus 4 in 28 Mauna Kea lavas) when compared with most oceanic basalts.
- Label:
- Geology
- Date:
- 1991
- Collection:
- Periodicals