Temporal-compositional-isotopic trends in rejuvenated-stage magmas of Kauai, Hawaii, and implications for mantle melting processes

Peter W Reiners, Bruce K. Nelson

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Primitive, low-silica and high-alkali magmas that erupt late in the evolution of most ocean island volcanoes are highly enriched in incompatible trace elements, yet their isotopic compositions require a time-integrated mantle source history of incompatible-element depletion. Reconciling these observations has traditionally required either extremely low degrees of partial melting of depleted mantle (commonly less than 0.2%), invoking an unusual mantle source recently enriched in incompatible elements or extensive melt-mantle interaction. Analyses of stratigraphic sequences of rejuvenated-stage volcanics of Kauai, Hawaii show previously unrecognized isotopic-trace element correlations, as well as temporal variations within monogenetic lava sequences that provide evidence of variable degrees of melting of several distinct mantle sources. Inter-element and isotopic-trace-element correlations indicate little or no chromatographic effects on melt compositions, inconsistent with the expected effects of significant melt-mantle reaction as the source of their incompatible-element enrichment. Trace-element compositions of rejuvenated-stage magmas can be produced by melting of typical depleted mantle sources only if they are mixtures of small- and large-degree (0.1% and 2-15%, depending on source mineralogy) melts of isotopically distinct sources. The simplest model for the Koloa Volcanics, however, consistent with previous interpretations of other Hawaiian lavas, is that they are derived from a range of incompatible-element enriched mantle sources variably metasomatized by small-degree melts of depleted mantle. Isotopic-trace-element trends in the Koloa magmas (of the opposite sense as the overall Hawaiian trend) are best explained by a positive correlation between the extent of source metasomatism and degree of melting to produce the Koloa magmas. Systematic decreases in incompatible element concentrations within individual eruption sequences probably represent sequential eruption of progressively larger-degree melt, possibly caused by vertical zonation in extent of melting in the source regions, or extraction of low-degree melts from surrounding mantle by early-ascending magma batches.

Original languageEnglish (US)
Pages (from-to)2347-2368
Number of pages22
JournalGeochimica et Cosmochimica Acta
Volume62
Issue number13
DOIs
StatePublished - Jul 1998
Externally publishedYes

Fingerprint

Trace Elements
Melting
melting
melt
mantle source
mantle
trace element
Chemical analysis
Volcanoes
Mineralogy
volcanic eruption
Alkalies
Silicon Dioxide
metasomatism
trend
lava
zonation
partial melting
mineralogy
temporal variation

Keywords

  • Hawaii
  • Kauai
  • Magmas
  • Mantle
  • Melting
  • United States

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

Temporal-compositional-isotopic trends in rejuvenated-stage magmas of Kauai, Hawaii, and implications for mantle melting processes. / Reiners, Peter W; Nelson, Bruce K.

In: Geochimica et Cosmochimica Acta, Vol. 62, No. 13, 07.1998, p. 2347-2368.

Research output: Contribution to journalArticle

@article{d715b26f11fd4494872666e885f5a3c6,
title = "Temporal-compositional-isotopic trends in rejuvenated-stage magmas of Kauai, Hawaii, and implications for mantle melting processes",
abstract = "Primitive, low-silica and high-alkali magmas that erupt late in the evolution of most ocean island volcanoes are highly enriched in incompatible trace elements, yet their isotopic compositions require a time-integrated mantle source history of incompatible-element depletion. Reconciling these observations has traditionally required either extremely low degrees of partial melting of depleted mantle (commonly less than 0.2{\%}), invoking an unusual mantle source recently enriched in incompatible elements or extensive melt-mantle interaction. Analyses of stratigraphic sequences of rejuvenated-stage volcanics of Kauai, Hawaii show previously unrecognized isotopic-trace element correlations, as well as temporal variations within monogenetic lava sequences that provide evidence of variable degrees of melting of several distinct mantle sources. Inter-element and isotopic-trace-element correlations indicate little or no chromatographic effects on melt compositions, inconsistent with the expected effects of significant melt-mantle reaction as the source of their incompatible-element enrichment. Trace-element compositions of rejuvenated-stage magmas can be produced by melting of typical depleted mantle sources only if they are mixtures of small- and large-degree (0.1{\%} and 2-15{\%}, depending on source mineralogy) melts of isotopically distinct sources. The simplest model for the Koloa Volcanics, however, consistent with previous interpretations of other Hawaiian lavas, is that they are derived from a range of incompatible-element enriched mantle sources variably metasomatized by small-degree melts of depleted mantle. Isotopic-trace-element trends in the Koloa magmas (of the opposite sense as the overall Hawaiian trend) are best explained by a positive correlation between the extent of source metasomatism and degree of melting to produce the Koloa magmas. Systematic decreases in incompatible element concentrations within individual eruption sequences probably represent sequential eruption of progressively larger-degree melt, possibly caused by vertical zonation in extent of melting in the source regions, or extraction of low-degree melts from surrounding mantle by early-ascending magma batches.",
keywords = "Hawaii, Kauai, Magmas, Mantle, Melting, United States",
author = "Reiners, {Peter W} and Nelson, {Bruce K.}",
year = "1998",
month = "7",
doi = "10.1016/S0016-7037(98)00141-0",
language = "English (US)",
volume = "62",
pages = "2347--2368",
journal = "Geochmica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Elsevier Limited",
number = "13",

}

TY - JOUR

T1 - Temporal-compositional-isotopic trends in rejuvenated-stage magmas of Kauai, Hawaii, and implications for mantle melting processes

AU - Reiners, Peter W

AU - Nelson, Bruce K.

PY - 1998/7

Y1 - 1998/7

N2 - Primitive, low-silica and high-alkali magmas that erupt late in the evolution of most ocean island volcanoes are highly enriched in incompatible trace elements, yet their isotopic compositions require a time-integrated mantle source history of incompatible-element depletion. Reconciling these observations has traditionally required either extremely low degrees of partial melting of depleted mantle (commonly less than 0.2%), invoking an unusual mantle source recently enriched in incompatible elements or extensive melt-mantle interaction. Analyses of stratigraphic sequences of rejuvenated-stage volcanics of Kauai, Hawaii show previously unrecognized isotopic-trace element correlations, as well as temporal variations within monogenetic lava sequences that provide evidence of variable degrees of melting of several distinct mantle sources. Inter-element and isotopic-trace-element correlations indicate little or no chromatographic effects on melt compositions, inconsistent with the expected effects of significant melt-mantle reaction as the source of their incompatible-element enrichment. Trace-element compositions of rejuvenated-stage magmas can be produced by melting of typical depleted mantle sources only if they are mixtures of small- and large-degree (0.1% and 2-15%, depending on source mineralogy) melts of isotopically distinct sources. The simplest model for the Koloa Volcanics, however, consistent with previous interpretations of other Hawaiian lavas, is that they are derived from a range of incompatible-element enriched mantle sources variably metasomatized by small-degree melts of depleted mantle. Isotopic-trace-element trends in the Koloa magmas (of the opposite sense as the overall Hawaiian trend) are best explained by a positive correlation between the extent of source metasomatism and degree of melting to produce the Koloa magmas. Systematic decreases in incompatible element concentrations within individual eruption sequences probably represent sequential eruption of progressively larger-degree melt, possibly caused by vertical zonation in extent of melting in the source regions, or extraction of low-degree melts from surrounding mantle by early-ascending magma batches.

AB - Primitive, low-silica and high-alkali magmas that erupt late in the evolution of most ocean island volcanoes are highly enriched in incompatible trace elements, yet their isotopic compositions require a time-integrated mantle source history of incompatible-element depletion. Reconciling these observations has traditionally required either extremely low degrees of partial melting of depleted mantle (commonly less than 0.2%), invoking an unusual mantle source recently enriched in incompatible elements or extensive melt-mantle interaction. Analyses of stratigraphic sequences of rejuvenated-stage volcanics of Kauai, Hawaii show previously unrecognized isotopic-trace element correlations, as well as temporal variations within monogenetic lava sequences that provide evidence of variable degrees of melting of several distinct mantle sources. Inter-element and isotopic-trace-element correlations indicate little or no chromatographic effects on melt compositions, inconsistent with the expected effects of significant melt-mantle reaction as the source of their incompatible-element enrichment. Trace-element compositions of rejuvenated-stage magmas can be produced by melting of typical depleted mantle sources only if they are mixtures of small- and large-degree (0.1% and 2-15%, depending on source mineralogy) melts of isotopically distinct sources. The simplest model for the Koloa Volcanics, however, consistent with previous interpretations of other Hawaiian lavas, is that they are derived from a range of incompatible-element enriched mantle sources variably metasomatized by small-degree melts of depleted mantle. Isotopic-trace-element trends in the Koloa magmas (of the opposite sense as the overall Hawaiian trend) are best explained by a positive correlation between the extent of source metasomatism and degree of melting to produce the Koloa magmas. Systematic decreases in incompatible element concentrations within individual eruption sequences probably represent sequential eruption of progressively larger-degree melt, possibly caused by vertical zonation in extent of melting in the source regions, or extraction of low-degree melts from surrounding mantle by early-ascending magma batches.

KW - Hawaii

KW - Kauai

KW - Magmas

KW - Mantle

KW - Melting

KW - United States

UR - http://www.scopus.com/inward/record.url?scp=0032456357&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032456357&partnerID=8YFLogxK

U2 - 10.1016/S0016-7037(98)00141-0

DO - 10.1016/S0016-7037(98)00141-0

M3 - Article

AN - SCOPUS:0032456357

VL - 62

SP - 2347

EP - 2368

JO - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 13

ER -