S, O and Sr isotope systematics of active vent materials from the Mariana backarc basin spreading axis at 18°N

Minoru Kusakabe, Shingo Mayeda, Eizou Nakamura

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

Stable isotope ratios of S, O and Sr have been measured for active vent materials which were first found and sampled in April 1987 from the Mariana backarc spreading axis at 18°N. Chimneys consisted mostly of barite with a lesser proportion of sulfide minerals such as sphalerite, galena, chalcopyrite and pyrite. The δ34S values of sphalerite and galena taken from several chimneys and various parts of a chimney showed a narrow range from 2.1 to 3.1‰, suggesting uniform conditions of fluid chemistry during chimney growth. The sulfur isotopic results imply a contribution of hydrogen sulfide reduced from seawater sulfate in the deep hydrothermal reaction zone, considering that fresh glasses of the Mariana Trough basalts have δ34S = -0.6 ± 0.3‰. Sulfur isotopic compositions of hydrogen sulfide in the high temperature vent fluids (δ34S = 3.6-4.8‰) which are higher than those of the sulfide minerals suggest the secondary addition of hydrogen sulfide partially reduced from entrained seawater SO42- at a basal part of the chimneys. This interpretation is consistent with the δ34S values of barite (21-22‰) that are higher than those of seawater sulfate. The residence time of the entrained SO42- was an order of an hour on a basis of oxygen isotopic disequilibrium of barite. Strontium isotopic variations of barite and vent waters indicated that Sr in barite was mostly derived from the Mariana Trough basalts with a slight contribution from Sr in circulating sea-water, and that 10-20% mixing of seawater with ascending hydrothermal fluids induced precipitation of barite at the sea-floor.

Original languageEnglish
Pages (from-to)275-282
Number of pages8
JournalEarth and Planetary Science Letters
Volume100
Issue number1-3
DOIs
Publication statusPublished - 1990

Fingerprint

Barium Sulfate
backarc basin
barite
Vents
vents
chimneys
Chimneys
Isotopes
isotopes
isotope
Seawater
Hydrogen Sulfide
hydrogen sulfide
seawater
Sulfide minerals
zincblende
galena
sphalerite
troughs
Sulfur

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)
  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

S, O and Sr isotope systematics of active vent materials from the Mariana backarc basin spreading axis at 18°N. / Kusakabe, Minoru; Mayeda, Shingo; Nakamura, Eizou.

In: Earth and Planetary Science Letters, Vol. 100, No. 1-3, 1990, p. 275-282.

Research output: Contribution to journalArticle

@article{a6ee4ac1f1834644b3d03310b45ae4c5,
title = "S, O and Sr isotope systematics of active vent materials from the Mariana backarc basin spreading axis at 18°N",
abstract = "Stable isotope ratios of S, O and Sr have been measured for active vent materials which were first found and sampled in April 1987 from the Mariana backarc spreading axis at 18°N. Chimneys consisted mostly of barite with a lesser proportion of sulfide minerals such as sphalerite, galena, chalcopyrite and pyrite. The δ34S values of sphalerite and galena taken from several chimneys and various parts of a chimney showed a narrow range from 2.1 to 3.1‰, suggesting uniform conditions of fluid chemistry during chimney growth. The sulfur isotopic results imply a contribution of hydrogen sulfide reduced from seawater sulfate in the deep hydrothermal reaction zone, considering that fresh glasses of the Mariana Trough basalts have δ34S = -0.6 ± 0.3‰. Sulfur isotopic compositions of hydrogen sulfide in the high temperature vent fluids (δ34S = 3.6-4.8‰) which are higher than those of the sulfide minerals suggest the secondary addition of hydrogen sulfide partially reduced from entrained seawater SO42- at a basal part of the chimneys. This interpretation is consistent with the δ34S values of barite (21-22‰) that are higher than those of seawater sulfate. The residence time of the entrained SO42- was an order of an hour on a basis of oxygen isotopic disequilibrium of barite. Strontium isotopic variations of barite and vent waters indicated that Sr in barite was mostly derived from the Mariana Trough basalts with a slight contribution from Sr in circulating sea-water, and that 10-20{\%} mixing of seawater with ascending hydrothermal fluids induced precipitation of barite at the sea-floor.",
author = "Minoru Kusakabe and Shingo Mayeda and Eizou Nakamura",
year = "1990",
doi = "10.1016/0012-821X(90)90190-9",
language = "English",
volume = "100",
pages = "275--282",
journal = "Earth and Planetary Sciences Letters",
issn = "0012-821X",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - S, O and Sr isotope systematics of active vent materials from the Mariana backarc basin spreading axis at 18°N

AU - Kusakabe, Minoru

AU - Mayeda, Shingo

AU - Nakamura, Eizou

PY - 1990

Y1 - 1990

N2 - Stable isotope ratios of S, O and Sr have been measured for active vent materials which were first found and sampled in April 1987 from the Mariana backarc spreading axis at 18°N. Chimneys consisted mostly of barite with a lesser proportion of sulfide minerals such as sphalerite, galena, chalcopyrite and pyrite. The δ34S values of sphalerite and galena taken from several chimneys and various parts of a chimney showed a narrow range from 2.1 to 3.1‰, suggesting uniform conditions of fluid chemistry during chimney growth. The sulfur isotopic results imply a contribution of hydrogen sulfide reduced from seawater sulfate in the deep hydrothermal reaction zone, considering that fresh glasses of the Mariana Trough basalts have δ34S = -0.6 ± 0.3‰. Sulfur isotopic compositions of hydrogen sulfide in the high temperature vent fluids (δ34S = 3.6-4.8‰) which are higher than those of the sulfide minerals suggest the secondary addition of hydrogen sulfide partially reduced from entrained seawater SO42- at a basal part of the chimneys. This interpretation is consistent with the δ34S values of barite (21-22‰) that are higher than those of seawater sulfate. The residence time of the entrained SO42- was an order of an hour on a basis of oxygen isotopic disequilibrium of barite. Strontium isotopic variations of barite and vent waters indicated that Sr in barite was mostly derived from the Mariana Trough basalts with a slight contribution from Sr in circulating sea-water, and that 10-20% mixing of seawater with ascending hydrothermal fluids induced precipitation of barite at the sea-floor.

AB - Stable isotope ratios of S, O and Sr have been measured for active vent materials which were first found and sampled in April 1987 from the Mariana backarc spreading axis at 18°N. Chimneys consisted mostly of barite with a lesser proportion of sulfide minerals such as sphalerite, galena, chalcopyrite and pyrite. The δ34S values of sphalerite and galena taken from several chimneys and various parts of a chimney showed a narrow range from 2.1 to 3.1‰, suggesting uniform conditions of fluid chemistry during chimney growth. The sulfur isotopic results imply a contribution of hydrogen sulfide reduced from seawater sulfate in the deep hydrothermal reaction zone, considering that fresh glasses of the Mariana Trough basalts have δ34S = -0.6 ± 0.3‰. Sulfur isotopic compositions of hydrogen sulfide in the high temperature vent fluids (δ34S = 3.6-4.8‰) which are higher than those of the sulfide minerals suggest the secondary addition of hydrogen sulfide partially reduced from entrained seawater SO42- at a basal part of the chimneys. This interpretation is consistent with the δ34S values of barite (21-22‰) that are higher than those of seawater sulfate. The residence time of the entrained SO42- was an order of an hour on a basis of oxygen isotopic disequilibrium of barite. Strontium isotopic variations of barite and vent waters indicated that Sr in barite was mostly derived from the Mariana Trough basalts with a slight contribution from Sr in circulating sea-water, and that 10-20% mixing of seawater with ascending hydrothermal fluids induced precipitation of barite at the sea-floor.

UR - http://www.scopus.com/inward/record.url?scp=0025658598&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025658598&partnerID=8YFLogxK

U2 - 10.1016/0012-821X(90)90190-9

DO - 10.1016/0012-821X(90)90190-9

M3 - Article

AN - SCOPUS:0025658598

VL - 100

SP - 275

EP - 282

JO - Earth and Planetary Sciences Letters

JF - Earth and Planetary Sciences Letters

SN - 0012-821X

IS - 1-3

ER -