Crystal and magma residence at Kilauea Volcano, Hawaii

230Th-226Ra dating of the 1955 east rift eruption

Kari M. Cooper, Mary Reid, Michael T. Murrell, David A. Clague

Research output: Contribution to journalArticle

85 Citations (Scopus)

Abstract

Previous estimates of crustal storage time of magmas at Kilauea Volcano, Hawaii, range from a few years to a few thousand years, leading to considerable uncertainty in the time scales of processes of magmatic storage and differentiation. We present a new approach for determining minimum magma residence times which involves dating phenocrysts in a magma using 226Ra-230Th disequilibria, and apply this approach to the early phase of the 1955 east rift eruption at Kilauea. When fractionation of Ra from Ba (a proxy for initial Ra in the crystals) during crystal growth is considered along with the effects of inclusions in the minerals, the data are consistent with co-precipitation of plagioclase and clinopyroxene from a melt represented by the groundmass at a mean age of 1000-400+300 a. Unless a significant fraction (> 30%) of the crystals are remnants from an earlier batch of evolved magma in the system, these data constrain the minimum magmatic residence time to be ∼ 550 yr, considerably longer than most previous estimates of storage time at Kilauea as well as those for some other basaltic systems. For the temperature interval of augite+plagioclase growth in the early 1955 magma, a maximum constant cooling rate of 0.1°C/yr (1 x 10-5°C/h) is derived from the minimum magmatic residence time of 550 yr. The total magma storage time would be > 2500 yr if this cooling rate applied to the entire thermal history of the magma, although a more complex cooling history where cooling rates were more rapid early in the storage history is permissive of a total residence time which is not much longer than 550 yr. The disparate estimates of magma residence at Kilauea may reflect the uncertainties in the methods of estimation in addition to true variations in storage time for different batches of magma. More work is necessary in order to determine whether a long residence time is characteristic of rift zone lavas and/or of Kilauean lavas in general.

Original languageEnglish (US)
Pages (from-to)703-718
Number of pages16
JournalEarth and Planetary Science Letters
Volume184
Issue number3-4
DOIs
StatePublished - 2001
Externally publishedYes

Fingerprint

Geochronology
Volcanoes
dating
volcanoes
volcanic eruptions
magma
volcano
volcanic eruption
crystal
Cooling
Crystals
residence time
Fractionation
Coprecipitation
Crystallization
crystals
Minerals
cooling
histories
plagioclase

Keywords

  • Kilauea
  • Residence time
  • Th-230/RA-226

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

Cite this

Crystal and magma residence at Kilauea Volcano, Hawaii : 230Th-226Ra dating of the 1955 east rift eruption. / Cooper, Kari M.; Reid, Mary; Murrell, Michael T.; Clague, David A.

In: Earth and Planetary Science Letters, Vol. 184, No. 3-4, 2001, p. 703-718.

Research output: Contribution to journalArticle

Cooper, Kari M. ; Reid, Mary ; Murrell, Michael T. ; Clague, David A. / Crystal and magma residence at Kilauea Volcano, Hawaii : 230Th-226Ra dating of the 1955 east rift eruption. In: Earth and Planetary Science Letters. 2001 ; Vol. 184, No. 3-4. pp. 703-718.
@article{1ef7f043dca94ae4b3a4ce5e6eca3316,
title = "Crystal and magma residence at Kilauea Volcano, Hawaii: 230Th-226Ra dating of the 1955 east rift eruption",
abstract = "Previous estimates of crustal storage time of magmas at Kilauea Volcano, Hawaii, range from a few years to a few thousand years, leading to considerable uncertainty in the time scales of processes of magmatic storage and differentiation. We present a new approach for determining minimum magma residence times which involves dating phenocrysts in a magma using 226Ra-230Th disequilibria, and apply this approach to the early phase of the 1955 east rift eruption at Kilauea. When fractionation of Ra from Ba (a proxy for initial Ra in the crystals) during crystal growth is considered along with the effects of inclusions in the minerals, the data are consistent with co-precipitation of plagioclase and clinopyroxene from a melt represented by the groundmass at a mean age of 1000-400+300 a. Unless a significant fraction (> 30{\%}) of the crystals are remnants from an earlier batch of evolved magma in the system, these data constrain the minimum magmatic residence time to be ∼ 550 yr, considerably longer than most previous estimates of storage time at Kilauea as well as those for some other basaltic systems. For the temperature interval of augite+plagioclase growth in the early 1955 magma, a maximum constant cooling rate of 0.1°C/yr (1 x 10-5°C/h) is derived from the minimum magmatic residence time of 550 yr. The total magma storage time would be > 2500 yr if this cooling rate applied to the entire thermal history of the magma, although a more complex cooling history where cooling rates were more rapid early in the storage history is permissive of a total residence time which is not much longer than 550 yr. The disparate estimates of magma residence at Kilauea may reflect the uncertainties in the methods of estimation in addition to true variations in storage time for different batches of magma. More work is necessary in order to determine whether a long residence time is characteristic of rift zone lavas and/or of Kilauean lavas in general.",
keywords = "Kilauea, Residence time, Th-230/RA-226",
author = "Cooper, {Kari M.} and Mary Reid and Murrell, {Michael T.} and Clague, {David A.}",
year = "2001",
doi = "10.1016/S0012-821X(00)00341-1",
language = "English (US)",
volume = "184",
pages = "703--718",
journal = "Earth and Planetary Sciences Letters",
issn = "0012-821X",
publisher = "Elsevier",
number = "3-4",

}

TY - JOUR

T1 - Crystal and magma residence at Kilauea Volcano, Hawaii

T2 - 230Th-226Ra dating of the 1955 east rift eruption

AU - Cooper, Kari M.

AU - Reid, Mary

AU - Murrell, Michael T.

AU - Clague, David A.

PY - 2001

Y1 - 2001

N2 - Previous estimates of crustal storage time of magmas at Kilauea Volcano, Hawaii, range from a few years to a few thousand years, leading to considerable uncertainty in the time scales of processes of magmatic storage and differentiation. We present a new approach for determining minimum magma residence times which involves dating phenocrysts in a magma using 226Ra-230Th disequilibria, and apply this approach to the early phase of the 1955 east rift eruption at Kilauea. When fractionation of Ra from Ba (a proxy for initial Ra in the crystals) during crystal growth is considered along with the effects of inclusions in the minerals, the data are consistent with co-precipitation of plagioclase and clinopyroxene from a melt represented by the groundmass at a mean age of 1000-400+300 a. Unless a significant fraction (> 30%) of the crystals are remnants from an earlier batch of evolved magma in the system, these data constrain the minimum magmatic residence time to be ∼ 550 yr, considerably longer than most previous estimates of storage time at Kilauea as well as those for some other basaltic systems. For the temperature interval of augite+plagioclase growth in the early 1955 magma, a maximum constant cooling rate of 0.1°C/yr (1 x 10-5°C/h) is derived from the minimum magmatic residence time of 550 yr. The total magma storage time would be > 2500 yr if this cooling rate applied to the entire thermal history of the magma, although a more complex cooling history where cooling rates were more rapid early in the storage history is permissive of a total residence time which is not much longer than 550 yr. The disparate estimates of magma residence at Kilauea may reflect the uncertainties in the methods of estimation in addition to true variations in storage time for different batches of magma. More work is necessary in order to determine whether a long residence time is characteristic of rift zone lavas and/or of Kilauean lavas in general.

AB - Previous estimates of crustal storage time of magmas at Kilauea Volcano, Hawaii, range from a few years to a few thousand years, leading to considerable uncertainty in the time scales of processes of magmatic storage and differentiation. We present a new approach for determining minimum magma residence times which involves dating phenocrysts in a magma using 226Ra-230Th disequilibria, and apply this approach to the early phase of the 1955 east rift eruption at Kilauea. When fractionation of Ra from Ba (a proxy for initial Ra in the crystals) during crystal growth is considered along with the effects of inclusions in the minerals, the data are consistent with co-precipitation of plagioclase and clinopyroxene from a melt represented by the groundmass at a mean age of 1000-400+300 a. Unless a significant fraction (> 30%) of the crystals are remnants from an earlier batch of evolved magma in the system, these data constrain the minimum magmatic residence time to be ∼ 550 yr, considerably longer than most previous estimates of storage time at Kilauea as well as those for some other basaltic systems. For the temperature interval of augite+plagioclase growth in the early 1955 magma, a maximum constant cooling rate of 0.1°C/yr (1 x 10-5°C/h) is derived from the minimum magmatic residence time of 550 yr. The total magma storage time would be > 2500 yr if this cooling rate applied to the entire thermal history of the magma, although a more complex cooling history where cooling rates were more rapid early in the storage history is permissive of a total residence time which is not much longer than 550 yr. The disparate estimates of magma residence at Kilauea may reflect the uncertainties in the methods of estimation in addition to true variations in storage time for different batches of magma. More work is necessary in order to determine whether a long residence time is characteristic of rift zone lavas and/or of Kilauean lavas in general.

KW - Kilauea

KW - Residence time

KW - Th-230/RA-226

UR - http://www.scopus.com/inward/record.url?scp=0035076469&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035076469&partnerID=8YFLogxK

U2 - 10.1016/S0012-821X(00)00341-1

DO - 10.1016/S0012-821X(00)00341-1

M3 - Article

VL - 184

SP - 703

EP - 718

JO - Earth and Planetary Sciences Letters

JF - Earth and Planetary Sciences Letters

SN - 0012-821X

IS - 3-4

ER -