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Stable isotopic signatures of authigenic minerals in a Holocene ophiolitic debris flow, Southland, New Zealand

Published online by Cambridge University Press:  09 July 2018

D. Craw
Affiliation:
Geology Department, University of Otago, PO Box 56, Dunedin, New Zealand
P. Blattner
Affiliation:
Institute of Geological and Nuclear Sciences Ltd, PO Box 31312, Lower Hutt, New Zealand
C. A. Landis
Affiliation:
Geology Department, University of Otago, PO Box 56, Dunedin, New Zealand

Abstract

Authigenic chrysotile, stevensite, calcite, aragonite and pectolite have formed together in a Holocene ophiolitic debris flow in Southland, New Zealand. Mineral growth occurred about 4700-5700 years ago. The temperature of formation of these minerals is estimated from climatological data to be 5–10°C Surface water and groundwater δ180 is currently about –10‰, and was estimated to be about –9.5±1‰ during mineralization. Coexisting calcite (δ180 = +23‰) and aragonite (δl8O = +24‰) were in equilibrium with each other and with the groundwater at 5–10°C Stevensite δ180 is +14 to +16‰, chrysotile has δ180 = +5.5‰, and authigenic pectolite has δ180 near +10‰. Carbon isotope ratios for calcite and aragonite are strongly depleted (δ13C = –13 to –18) which suggests that dissolved CO2 had δ13C below -27. This isotopically light carbon probably resulted from a high organic component of carbon dissolved in the groundwater.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1995

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References

Barnes, I., O'neil, J.R. & Trescases, J.J. (1978) Present day serpentinization in New Caledonia, Oman and Yugoslavia. Geochim. Cosmochim. Acta, 42, 144145.CrossRefGoogle Scholar
Blattner, P. (1975) Oxygen isotopic composition of fissure-grown quartz, adularia and calcite from Broadlands geothermal field, New Zealand. Am. J. Sci. 275, 785800.CrossRefGoogle Scholar
Bornnga, Y. & Javov, M. (1973) Comments on oxygen isotope geothermometry. Earth Planet. Sci. Letters, 20, 250265.Google Scholar
Clark, I.D., Fortes, J-C. & Fritz, P. (1992) Stable isotope disequilibria in travertine from high pH waters: Laboratory investigations and field observations from Oman. Geochim. Cosmochim. Acta, 56, 20412050.CrossRefGoogle Scholar
Craw, D. & Landis, C.A. (1980) Authigenic pectolite, stevensite and pyroaurite in a quaternary debris flow, Southland, New Zealand. J. Sed. Pet. 50, 497504.Google Scholar
Craw, D., Landis, C.A. & Kelsey, P.I. (1987) Authigenic chrysotile formation in the matrix of Quaternary debris flows, Northern Southland, New Zealand. Clays Clay Miner. 35, 4352.CrossRefGoogle Scholar
Deines, P. (1980) The isotopic composition of reduced organic carbon. Pp. 329406 in: Handbook of Environmental Isotope Geochemistry (Fritz, P. & Fortes, J.C., editors), 1. Elsevier, Amsterdam.Google Scholar
Fehn, U., Peters, E.K., Tullai-Frrzpatrick, S., Kubrick, P.W., Sharma, P., Teng, D., Gove, H.E. & Elmore, D. (1992) 29I and 36C1 concentrations in waters of the eastern Clear Lake area, California. Residence times and source ages of hydrothermal fluids. Geochim. Cosmochim. Acta, 56, 20692079.CrossRefGoogle Scholar
Field, C.W. & Fifarek, R.H. (1985) Light stable isotope systematics in the epithermal environment. Rev. Econ. Geol. 2, 99128.Google Scholar
Friedman, I. & O'neil, J.R. (1977) Compilation of stable isotope fractionation factors of geochemical interest. U.S. Geol. Survey Prof. Paper, 440KK, KK1-KK12.Google Scholar
Grossman, E.T. & KU, T.L. (1981) Aragonite-water isotopic paleotemperature scale based on the benthic foraminifera Hoeglundia elegans. Geol. Soc. Amer. Abstracts with Programs 13, 464.Google Scholar
Hamza, M.S. & Epstein, S. (1980) Oxygen isotopic fractionation between oxygen of different sites in hydroxyl bearing silicate minerals. Geochim. Cosmochim. Acta, 44, 173182.CrossRefGoogle Scholar
Joussaume, S., Sadourny, R. & Jouzel, J. (1984) A general circulation model of water isotope cycles in the atmosphere. Nature, 311, 2429.CrossRefGoogle Scholar
Lamb, H.H. (1977) Climate, Past and Future,Vol. 2. Methuen, London.Google Scholar
N.Z. Meteorological SERVICE (1980) Summary of climatological observations to 1980. N.Z. Meteorol. Service Misc. Publ. 17i7.Google Scholar
O'neil, J.R. & Barnes, I. (1971) 13C and 180 compositions in some fresh-water carbonates associated with ultramafic rocks and serpentinites: Western United States. Geochim. Cosmochim. Acta, 35, 687697.CrossRefGoogle Scholar
Savin, S.M. & Lee, M. (1988) Isotopic studies of phyllosilicates. Pp. 189223 in: Hydrous Phyllosi-licates (Bailey, S.W., editor), Reviews in Mineralogy, 19. Mineralogical Society of America, Washington.CrossRefGoogle Scholar
Tarutani, T., Clayton, R.N. & Mayeda, T.K. (1969) The effect of polymorphism and magnesium substitution on oxygen isotope fractionation between calcium carbonate and water. Geochim. Cosmochim. Acta, 33, 987996.CrossRefGoogle Scholar
Veizer, J. (1983) Trace elements and isotopes in sedimentary carbonates. Pp. 265299 in: Carbonates, Mineralogy and Chemistry (Reeder, R.J., editor) Reviews in Mineralogy, 11, Mineralogical Society of America, Washington.CrossRefGoogle Scholar
Wenner, D.B. (1979) Hydrogen, oxygen and carbon isotopic evidence for the origin of rodingites in serpentinized ultrarnafic rocks. Geochim. CosmocAirn. Acta, 43, 603614.CrossRefGoogle Scholar
Wenrnzr, D.B. & Taylor, H.P. (1971) Temperatures of serpentinization of ultramafic rocks based on 180/160 fractionation between coexisting serpentine and magnetite. Contrib. Mineral. Petrol. 32, 165185.Google Scholar
Yeh, H-W. & Savin, S.M. (1976) The extent of oxygen isotope exchange between clay minerals and sea water. Geochim. Cosmochim. Acta, 40, 743748.CrossRefGoogle Scholar
Yeh, H-W. & Savln, S.M. (1977) Mechanisms of burial metamorphism of argillaceous sediments. 3. O isotope evidence. Geol. Soc. Amer. Bull. 88, 13211330.2.0.CO;2>CrossRefGoogle Scholar