| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Journal of Petrology | Volume 44 | Number 12 | Pages 2313-2339 | 2003
© Oxford University Press 2003; all rights reserved
A Petrologic Perspective of K
lauea Volcano's Summit Magma Reservoir
1 DEPARTMENT OF GEOLOGY AND GEOPHYSICS, UNIVERSITY OF HAWAI'I, HONOLULU, HI 96822, USA
2 DEPARTMENT OF GEOSCIENCES, UNIVERSITY OF MASSACHUSETTS, AMHERST, MA 01003, USA
* Corresponding author. Telephone: 808-956-6641.E-mail: mogarcia{at}hawaii.edu
Two hundred years of magmatic history are documented by the lavas and tephra sampled from K
lauea's historical summit eruptions. This paper presents detailed petrographic and geochemical data for a comprehensive suite of samples erupted within or near Klauea's summit caldera since the 17th century. Our results elucidate the range of magmatic processes that operate within the volcano's summit magma reservoir and document two compositional trends that span nearly the entire known range for the volcano. Prior to the 1924 summit crater collapse, a trend of increasing incompatible element and CaO and decreasing SiO2 abundances (at a constant MgO) prevailed. Thereafter, the trend reversed direction and has persisted for the rest of the 20th century, including during the current Pu`u `
`
eruption. The rapid and systematic nature of these temporal geochemical variations indicates that the summit reservoir is a single, relatively small body rather than a plexus of dikes and sills. Olivine fractionation is the dominant petrologic process within this reservoir. Petrographic observations and olivine and whole-rock geochemical data suggest that the summit reservoir has a crown of aphyric, more evolved, low-density magma. Differentiation within this crown involving clinopyroxene and plagioclase is more extensive than previously recognized in Klauea summit lavas. The effects of crystal fractionation are superimposed upon an evolving hybrid magma composition produced by mixing new, mantle-derived magmas with more fractionated reservoir magma. Frequent eruptions of these hybrid reservoir magmas document the rapid variation in parental magma composition. These compositional variations correlate with magma supply rate; both are thought to be influenced by the degree of melting of small-scale source heterogeneities within the Hawaiian plume. However, Klauea's source compositions and partial-melting processes have varied only within a narrow range over the past 350 kyr.
KEY WORDS: basalt; geochemistry; magma reservoir; Klauea Volcano; Hawai'i
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J. P. Marske, M. O. Garcia, A. J. Pietruszka, J. M. Rhodes, and M. D. Norman Geochemical Variations during Kilauea's Pu'u 'O'o Eruption Reveal a Fine-scale Mixture of Mantle Heterogeneities within the Hawaiian Plume J. Petrology, July 1, 2008; 49(7): 1297 - 1318. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. O. Garcia, E. Ito, and J. M. Eiler Oxygen Isotope Evidence for Chemical Interaction of Ki lauea Historical Magmas with Basement Rocks J. Petrology, April 1, 2008; 49(4): 757 - 769. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Annell, J. S. Scoates, D. Weis, and A. Giret PETROLOGY OF FLOOD BASALTS AT THE THOLEIITIC ALKALIC TRANSITION AND PHENOCRYST COMPOSITIONS, MT. MARION DUFRESNE, KERGUELEN ARCHIPELAGO, SOUTHERN INDIAN OCEAN Can Mineral, August 1, 2007; 45(4): 809 - 835. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. J. Falloon, D. H. Green, and L. V. Danyushevsky Crystallization temperatures of tholeiite parental liquids: Implications for the existence of thermally driven mantle plumes Geological Society of America Special Papers, January 1, 2007; 430(0): 235 - 260. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Norman, M. O. Garcia, and A. J. Pietruszka Trace-element distribution coefficients for pyroxenes, plagioclase, and olivine in evolved tholeiites from the 1955 eruption of Kilauea Volcano, Hawai'i, and petrogenesis of differentiated rift-zone lavas American Mineralogist, May 1, 2005; 90(5-6): 888 - 899. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. GAFFNEY, B. K. NELSON, and J. BLICHERT-TOFT Geochemical Constraints on the Role of Oceanic Lithosphere in Intra-Volcano Heterogeneity at West Maui, Hawaii J. Petrology, August 1, 2004; 45(8): 1663 - 1687. [Abstract] [Full Text] [PDF]
|
|