Oxygen isotope exchange rate between dissolved sulfate and water at hydrothermal temperatures

Hitoshi Chiba, Hitoshi Sakai

Research output: Contribution to journalArticle

180 Citations (Scopus)

Abstract

Oxygen isotope exchange rate between dissolved sulfate and water was experimentally determined at 100, 200 and 300°C. The isotope exchange rate is strongly dependent on temperature and pH of the solution. Combining the temperature and pH dependence of the reaction rate, the exchange reaction was estimated to be first-order with respect to sulfate. The logarithm of apparent rate constant of exchange reaction at a given temperature is a function of the pH calculated at the experimental temperatures. From the pH dependence of the apparent rate constant, it was deduced that the isotope exchange reaction between dissolved sulfate and water proceeds through collision between H2SO04 and H2O at low pH, and between HSO-4 and H2O at intermediate pH. The isotope exchange rate obtained indicates that oxygen isotope geothermometry utilizing the studied isotope exchange is suitable for temperature estimation of geothermal reservoirs. The extrapolated half-life of this reaction to oceanic temperature is about 109 years, implying that exchange between oceanic sulfate and water cannot control the oxygen isotope ratio of oceanic sulfates.

Original languageEnglish
Pages (from-to)993-1000
Number of pages8
JournalGeochimica et Cosmochimica Acta
Volume49
Issue number4
DOIs
Publication statusPublished - 1985

Fingerprint

Oxygen Isotopes
exchange rate
Sulfates
oxygen isotope
sulfate
Isotopes
Water
isotope
temperature
water
Temperature
Rate constants
oxygen isotope ratio
geothermometry
half life
reaction rate
Reaction rates
collision

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

Oxygen isotope exchange rate between dissolved sulfate and water at hydrothermal temperatures. / Chiba, Hitoshi; Sakai, Hitoshi.

In: Geochimica et Cosmochimica Acta, Vol. 49, No. 4, 1985, p. 993-1000.

Research output: Contribution to journalArticle

@article{bb829b6eda7d4ce8a1062c132fb435d6,
title = "Oxygen isotope exchange rate between dissolved sulfate and water at hydrothermal temperatures",
abstract = "Oxygen isotope exchange rate between dissolved sulfate and water was experimentally determined at 100, 200 and 300°C. The isotope exchange rate is strongly dependent on temperature and pH of the solution. Combining the temperature and pH dependence of the reaction rate, the exchange reaction was estimated to be first-order with respect to sulfate. The logarithm of apparent rate constant of exchange reaction at a given temperature is a function of the pH calculated at the experimental temperatures. From the pH dependence of the apparent rate constant, it was deduced that the isotope exchange reaction between dissolved sulfate and water proceeds through collision between H2SO04 and H2O at low pH, and between HSO-4 and H2O at intermediate pH. The isotope exchange rate obtained indicates that oxygen isotope geothermometry utilizing the studied isotope exchange is suitable for temperature estimation of geothermal reservoirs. The extrapolated half-life of this reaction to oceanic temperature is about 109 years, implying that exchange between oceanic sulfate and water cannot control the oxygen isotope ratio of oceanic sulfates.",
author = "Hitoshi Chiba and Hitoshi Sakai",
year = "1985",
doi = "10.1016/0016-7037(85)90314-X",
language = "English",
volume = "49",
pages = "993--1000",
journal = "Geochmica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Elsevier Limited",
number = "4",

}

TY - JOUR

T1 - Oxygen isotope exchange rate between dissolved sulfate and water at hydrothermal temperatures

AU - Chiba, Hitoshi

AU - Sakai, Hitoshi

PY - 1985

Y1 - 1985

N2 - Oxygen isotope exchange rate between dissolved sulfate and water was experimentally determined at 100, 200 and 300°C. The isotope exchange rate is strongly dependent on temperature and pH of the solution. Combining the temperature and pH dependence of the reaction rate, the exchange reaction was estimated to be first-order with respect to sulfate. The logarithm of apparent rate constant of exchange reaction at a given temperature is a function of the pH calculated at the experimental temperatures. From the pH dependence of the apparent rate constant, it was deduced that the isotope exchange reaction between dissolved sulfate and water proceeds through collision between H2SO04 and H2O at low pH, and between HSO-4 and H2O at intermediate pH. The isotope exchange rate obtained indicates that oxygen isotope geothermometry utilizing the studied isotope exchange is suitable for temperature estimation of geothermal reservoirs. The extrapolated half-life of this reaction to oceanic temperature is about 109 years, implying that exchange between oceanic sulfate and water cannot control the oxygen isotope ratio of oceanic sulfates.

AB - Oxygen isotope exchange rate between dissolved sulfate and water was experimentally determined at 100, 200 and 300°C. The isotope exchange rate is strongly dependent on temperature and pH of the solution. Combining the temperature and pH dependence of the reaction rate, the exchange reaction was estimated to be first-order with respect to sulfate. The logarithm of apparent rate constant of exchange reaction at a given temperature is a function of the pH calculated at the experimental temperatures. From the pH dependence of the apparent rate constant, it was deduced that the isotope exchange reaction between dissolved sulfate and water proceeds through collision between H2SO04 and H2O at low pH, and between HSO-4 and H2O at intermediate pH. The isotope exchange rate obtained indicates that oxygen isotope geothermometry utilizing the studied isotope exchange is suitable for temperature estimation of geothermal reservoirs. The extrapolated half-life of this reaction to oceanic temperature is about 109 years, implying that exchange between oceanic sulfate and water cannot control the oxygen isotope ratio of oceanic sulfates.

UR - http://www.scopus.com/inward/record.url?scp=0022007824&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022007824&partnerID=8YFLogxK

U2 - 10.1016/0016-7037(85)90314-X

DO - 10.1016/0016-7037(85)90314-X

M3 - Article

VL - 49

SP - 993

EP - 1000

JO - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 4

ER -