Mahukona: The missing Hawaiian volcano

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1990)018<1111:MTMHV>2.3.CO;2· OSTI ID:5572883

Garcia, M O; Muenow, D W ^[1]; Kurz, M D ^[2]

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1. Univ. of Hawaii, Honolulu (USA)
2. Woods Hole Oceanographic Institution, MA (USA)

New bathymetric and geochemical data indicate that a seamount west of the island of Hawaii, Mahukona, is a Hawaiian shield volcano. Mahukona has weakly alkalic lavas that are geochemically distinct. They have high {sup 3}He/{sup 4}He ratios (12-21 times atmosphere), and high H{sub 2}O and Cl contents, which are indicative of the early state of development of Hawaiian volcanoes. The He and Sr isotopic values for Mahukona lavas are intermediate between those for lavas from Loihi and Manuna Loa volcanoes and may be indicative of a temporal evolution of Hawaiian magmas. Mahukona volcano became extinct at about 500 ka, perhaps before reaching sea level. It fills the previously assumed gap in the parallel chains of volcanoes forming the southern segment of the Hawaiian hotspot chain. The paired sequence of volcanoes was probably caused by the bifurcation of the Hawaiian mantle plume during its ascent, creating two primary areas of melting 30 to 40 km apart that have persisted for at least the past 4 m.y.

• OSTI ID: 5572883
• Journal Information: Geology; (USA), Journal Name: Geology; (USA) Vol. 18:11; ISSN GLGYB; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ALKALINE EARTH ISOTOPES
BATHYMETRY
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
DETECTION
EARTH MANTLE
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPLORATION
FEDERAL REGION IX
GEOCHEMISTRY
HALIDES
HALOGEN COMPOUNDS
HAWAII
HELIUM 3
HELIUM 4
HELIUM ISOTOPES
HOT SPOTS
HYDROGEN COMPOUNDS
ISOTOPE RATIO
ISOTOPES
LAVA
LEVELS
LIGHT NUCLEI
MAGMA
MAPS
NORTH AMERICA
NUCLEI
OXYGEN COMPOUNDS
SEA LEVEL
STABLE ISOTOPES
STRONTIUM ISOTOPES
UNDERWATER OPERATIONS
USA
VOLCANOES
WATER