Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-02T21:30:16.677Z Has data issue: false hasContentIssue false
  • English
  • Français

Oxygen Isotope Measurements of Albite-Quartz-Zeolite Mineral Assemblages, Hokonui Hills, Southland, New Zealand

Published online by Cambridge University Press:  02 April 2024

Mary L. Stallard  and
J. R. Boles
Mary L. Stallard*
Affiliation:
Department of Geological Sciences, University of California, Santa Barbara, California 93106
J. R. Boles
Affiliation:
Department of Geological Sciences, University of California, Santa Barbara, California 93106
*
1Present address: Weiss Associates, 2938 McClure Avenue, Oakland, California 94609
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The oxygen isotopes of albite, quartz, and zeolites from the Hokonui Hills, New Zealand, constrain crystallization temperatures and the type of pore fluids present during diagenesis. A section of altered vitric tuffs in this region contains an extremely sharp reaction boundary between a heulandite-chlorite assemblage containing fresh detrital plagioclase and a laumontite-albite-quartz assemblage. A laumontite vein follows the local joint pattern and forms the reaction boundary, suggesting that laumontitization occurred as a result of fracturing and increased fluid flow during uplift. The albite (δ18O = +15.0)-quartz (δ18O = +19.9 to +20.5) geothermometer constrains the temperature of alteration between 145° and 170°C with a pore water δ18O of +1.8 to +3.5. The tuff was buried to an estimated maximum temperature of about 225°C, indicating that alteration occurred after maximum burial.

Framework oxygen was extracted from zeolites by reaction with ClF3 after the zeolites were thermally dehydrated in a vacuum. Laumontite was dehydrated at 300°C, and stilbite at 150°C. The precision of the method is typically about ±0.45‰. Fractionation curves for dehydrated zeolites are based on a general expression from the literature for feldspars, which depends only on the Si/Al ratio of the mineral. Measured δ18O values for laumontite in the groundmass of the altered tuff were +14.4‰. The laumontite-quartz pair constrains the temperature to between 139° and 162°C, in excellent agreement with the albite-quartz pair, and supporting the petrographic observation of co-crystallizing albite-laumontite.

Oxygen isotope values for fracture-filling laumontite in the vitric tuff, as well as those for groundmass and vein laumontite from other parts of the stratigraphic section, cluster around +14.5, suggesting that laumontite probably crystallized under similar conditions throughout much of the section. Oxygen isotope values for stilbite veins from various parts of the section indicate that this mineral crystallized at lower temperatures than the laumontite, for a given fluid isotopic composition, in agreement with the observed cross-cutting of laumontite by stilbite.

Keywords

AlbiteDiagenesisFormation temperatureHeulanditeLaumontiteOxygen isotopesQuartzStilbiteZeolites
Type
Research Article
Information
Clays and Clay Minerals , Volume 37 , Issue 5 , October 1989 , pp. 409 - 418
Copyright
Copyright © 1989, The Clay Minerals Society

Footnotes

2

Presented at Symposium on the Geology, Genesis, Synthesis, and Use of Zeolites at 38th annual meeting of the Clay Minerals Society, Jackson, Mississippi, October 1986, convened by R. J. Donahoe. Manuscript reviewing and editing coordinated by R. J. Donahoe and R. A. Sheppard.

References

Boles, J. R., 1971 Stratigraphy, petrology, mineralogy, and metamorphism of mainly Triassic rocks, Hokonui Hills, Southland, New Zealand Dunedin, New Zealand University of Otago.Google Scholar
Boles, J. R., 1974 Structure, stratigraphy, and petrology of mainly Triassic rocks, Hokonui Hills, Southland, New Zealand New Zealand Geol. Geophys 17–2 337 – 374.CrossRefGoogle Scholar
Boles, J. R., 1982 Active albitization of plagioclase, Gulf Coast Tertiary Amer. J. Sci 282 165 – 180.CrossRefGoogle Scholar
Boles, J. R. and Coombs, D. S., 1975 Mineral reactions in zeolitic Triassic tuff, Hokonui Hills, New Zealand Geol. Soc. Amer. Bull 86 163 – 173.2.0.CO;2>CrossRefGoogle Scholar
Boles, J. R. and Coombs, D. S., 1977 Zeolite facies alteration of sandstone in the Southland syncline, New Zealand Amer. J. Sci 11 982 – 1012.CrossRefGoogle Scholar
Breck, D. W., 1974 Zeolite Molecular Sieves: Structure, Chemistry and Use New York Wiley.Google Scholar
Clayton, R. N., O’Neil, J. R. and Mayeda, T. K., 1972 Oxygen isotope exchange between quartz and water J. Geophys. Res 11 3057 – 3067.CrossRefGoogle Scholar
Clayton, R. N., Friedman, I., Graf, D. L., Mayeda, T. K., Meents, W. F. and Shimp, N. F., 1966 The origin of saline formation waters. I. Isotopic composition J. Geophys. Res 71 3869 – 3882.CrossRefGoogle Scholar
Clayton, R. N. and Mayeda, T. K., 1963 The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis Geochim. Cosmochim. Acta 27 43 – 52.CrossRefGoogle Scholar
Coombs, D. S., 1954 The nature and alteration of some Triassic sediments from Southland, New Zealand Trans. Roy. Soc. N.Z 82 65 – 109.Google Scholar
Coombs, D. S., Ellis, A. J., Fyfe, W. S. and Taylor, A. M., 1959 The zeolite facies, with comments on the interpretation of hydrothermal syntheses Geochim. Cosmochim. Acta 17 53 – 107.CrossRefGoogle Scholar
Friedman, I. and O’Neil, J. R. (1977) Compilation of stable isotope fractionation factors of geochemical interest: U.S. Geol. Survey Prof. Pap. 440–KK, 49 pp.Google Scholar
Fyfe, W. S., Turner, F. J. and Verhoogen, J. (1958) Metamorphic reactions and metamorphic facies: Geol. Soc. Amer. Mem. 73, 259 pp.Google Scholar
Gensse, C., Anderson, T. F. and Friplat, J. J., 1980 Study of oxygen mobility in some synthetic faujasites by isotopic exchange with CO2 J. Phys. Chem 84 3562 – 3567.CrossRefGoogle Scholar
Gottardi, G. and Galli, E., 1985 Natural Zeolites Berlin Springer-Verlag.CrossRefGoogle Scholar
Kastner, M. and Siever, R., 1979 Low temperature feldspars in sedimentary rocks Amer. J. Sci 279 435 – 479.CrossRefGoogle Scholar
Land, L. S. and Milliken, K. L., 1981 Feldspar diagenesis in the Frio Formation, Brazoria County, Texas Gulf Coast Geology 9 314 – 318.2.0.CO;2>CrossRefGoogle Scholar
O’Neil, J. R. and Taylor, H. P. Jr., 1967 The oxygen isotope and cation exchange chemistry of feldspars Amer. Mineral 52 1414 – 1437.Google Scholar
Savin, S. M., Fritz, P. and Fontes, J Ch, 1980 Oxygen and hydrogen isotope effects in low temperature mineral-water interactions Handbook of Environmental Isotope Geochemistry–Vol. 1 New York Elsevier 283 – 328.Google Scholar
Stallard, M. L., 1986 Albitization and zeolitization in Triassic/Jurassic volcanogenic rocks, Hokonui Hills, New Zealand Santa Barbara, California Univ. Calif..Google Scholar
Trevena, A. S. and Nash, N. P., 1981 An electron microprobe study of detrital feldspar J. Sed. Petrol 51 137 – 150.Google Scholar
von Ballmoos, R. and Meier, W. M., 1982 Oxygen-18 exchange between zeolite ZSM-5 and water J. Phys. Chem 86 2698 – 2700.CrossRefGoogle Scholar
Yeh, H. W. and Savin, S. M., 1977 The mechanism of burial metamorphism of argillaceous sediments, 3. Oxygen isotopic evidence Geol. Soc. Amer. Bull 88 1321 – 1330.2.0.CO;2>CrossRefGoogle Scholar