Geochemistry of Kauai volcanics and a mixing model for the origin of Hawaiian alkali basalts

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Authors:Feigenson, Mark D.
Author Affiliations:Primary:
Rutgers Univ., Dep. Geol. Sci., New Brunswick, NJ 08903, United States
Volume Title:Contributions to Mineralogy and Petrology
Source:Contributions to Mineralogy and Petrology, 87(2), p.109-119. Publisher: Springer International, Heidelberg-New York, International. ISSN: 0010-7999
Publication Date:1984
Note:In English. 30 refs.; illus. incl. 5 tables
Summary:A model is developed to explain the major, trace element, strontium and neodymium isotopic characteristics. Alkali basalts and tholeiites analyzed in this study show a complete transition in Sr and Nd isotopes. There is a well-constrained array on a Nd-Sr isotope correlation plot, explained by two-component mixing of Kauai tholeiite magma and a small amount of melt of East Pacific Rise source rock. Implications of this model are: (1) the main source of Hawaiian shield-building tholeiites is a mixture of subducted crust, primitive mantle and depleted asthenosphere that has been homogenized prior to melting, (2) early alkalic volcanism (as at Loihi Seamount) will be characterized by greater isotopic heterogeneity than will late-stage alkali basalt production, and (3) there are two distinct types of alkalic lavas erupted towards the end of magmatism. [P.Br.]
Subjects:Alkali basalts; Alkaline earth metals; Asthenosphere; Basalts; Crust; Genesis; Geochemistry; Geochronology; Igneous rocks; Isotopes; Lava; Magmas; Major elements; Mantle; Metals; Models; Nd-144/Nd-143; Neodymium; Petrology; Rare earths; Shield volcanoes; Sr-87/Sr-86; Stable isotopes; Strontium; Trace elements; Volcanic rocks; Volcanoes; Volcanology; East Pacific Ocean Islands; Hawaii; Kauai; Kauai County Hawaii; Oceania; Polynesia; United States; Evolution; Nd/Sr; Ratios
Coordinates:N220000 N220000 W1593000 W1593000
Abstract Numbers:85M/1673
Record ID:1985020749
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute.
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