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Toward a Comprehensive Upper Quaternary Tephra and Ignimbrite Stratigraphy in New Zealand using Electron Microprobe Analysis of Glass Shards

Published online by Cambridge University Press:  20 January 2017

P. C. Froggatt
P. C. Froggatt*
Affiliation:
Department of Geology, Victoria University of Wellington, Wellington, New Zealand
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Abstract

New Zealand Quaternary marine and terrestrial sequences contain numerous tephras, or volcanic-ash horizons, that are the distal correlatives of voluminous welded ignimbrite sheets, erupted from central North Island. Electron microprobe analyses of glass shards from the distal tephras demonstrate their homogeneity and are shown to identify each tephra examined. By matching tephras from stratigraphically controlled sequences, the first comprehensive tephra stratigraphy spanning from 50,000 to 700,000 yr ago and covering the New Zealand region is advanced.

Analyses on glass shards from the unwelded base of ignimbrite sheets are comparable to the distal tephra analyses and allow correlation between ignimbrites and to the distal tephras. The better exposed tephra record constrains the number of separate eruptive events and the stratigraphy of the ignimbrites, both of which were previously confused by lack of outcrop.

Samples from pumiceous marine sediments were found to contain two or more chemically distinct populations of glass. The pumice is in cross-bedded sands or sand lenses within conglomerate, attesting to a shallow high-energy environment where reworking could occur. However, each glass population could be matched to older, known tephras.

Type
Original Articles
Information
Quaternary Research , Volume 19 , Issue 2 , March 1983 , pp. 188 - 200
Copyright
University of Washington

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References

Bence, A.E., Albee, A.L.. 1968. Empirical correction factors for the electron microanalysis of silicate and oxides. Journal of Geology 76. 382–403.Google Scholar
Borchardt, G.A., Harvard, M.E., Schmitt, R.A.. 1971. Correlation of volcanic ash deposits by activation analysis of glass separates. Quaternary Research 1. 247–260.CrossRefGoogle Scholar
Briggs, N.D.. 1973. Investigations of New Zealand Pyroclastic-Flow Deposits. Unpublished thesis. Victoria University of Wellington.Google Scholar
Cerling, T.F., Cerling, B.W.. 1978. Correlation of reworked ash depsoits; the KBS Tuff, Northern Kenya Short Papers on the 4th International Conference, Geochronology, Cosmochronology, Isotope Geology, 1978 Zartman, R.E. U.S. Geol. Survey open-file report 78-701.Google Scholar
Cox, A.. 1969. A paleomagnetic study of secular variations in New Zealand. Earth and Planetary Science Letters 6. 257–267.Google Scholar
Cox, A.. 1971. Remnant magnetization and susceptibility of late Cenozoic rocks from New Zealand. New Zealand Journal of Geology and Geophysics 14. 192–207.Google Scholar
Ewart, A.. 1965. Mineralogy and petrogenesis of the Whakamaru Ignimbrite in the Maraetai area of the Taupo Volcanic zone, New Zealand. New Zealand Journal of Geology and Geophysics 8. 611–677.Google Scholar
Ewart, A.. 1968. The petrography of the central North Island rhyolitic lavas. Part 2. Regional petrography including notes on associated ash-flow pumice deposits. New Zealand Journal of Geology and Geophysics 11. 478–545.Google Scholar
Federman, A.N., Carey, S.N.. 1980. Electron microprobe correlation of tephra layers from eastern Mediterranean abyssal sediments and the island of Santorini. Quaternary Research 13. 160–171.Google Scholar
Healy, J., Vucetich, C.G., Pullar, W.A.. 1964. Stratigraphy and chronology of late Quaternary volcanic ash in Taupo, Rotorua and Gisborne districts. New Zealand Geological Survey Bulletin No. 73. .Google Scholar
Howorth, R., Froggatt, P.C., Vucetich, C.G., Collen, J.D.. 1981. Proceedings of Tephra WorkshopJune 30–July 1, 1980 Geology Department Victoria University, Publication No. 20.Google Scholar
Howorth, R., Rankin, P.C.. 1975. Multi-element characterisation of glass shards from stratigraphically correlated rhyolitic tephra units. Chemical Geology 15. 239–250.Google Scholar
Kingma, J.T.. 1971. Geology of the Te Aute Subdivision. New Zealand Geological Survey Bulletin No. 70. .Google Scholar
Kohn, B.P.. 1970. Identification of New Zealand tephra layers by emission spectrographic analysis of their titanomagnetite. Lithos 3. 361–368.Google Scholar
Kohn, B.P.. 1979. Identification and significance of a late Pleistocene tephra in Canterbury District, South Island, New Zealand. Quaternary Research 11. 78–92.Google Scholar
Kushiro, I., Nakamura, Y.. 1970. Petrology of some lunar crystalline rocks. Proceedings of Apollo II Lunar Science Conference Vol. 1.Google Scholar
Martin, R.C.. 1961. Stratigraphy and structural outline of the Taupo Volcanic Zone. New Zealand Journal of Geology and Geophysics 4. 449–478.Google Scholar
Milne, J.D.G.. 1973. Mt. Curl Tephra, a 230,000 years-old marker bed in New Zealand and its implications for Quaternary chronology. New Zealand Journal of Geology and Geophysics 16. 519–532.Google Scholar
Naeser, C.W., Nishimura, S., Te Punga, M.T.. 1980. Fission-track age of the Mangaroa Ash and tectonic implications at Wellington, New Zealand. New Zealand Journal of Geology and Geophysics 23. 615–620.Google Scholar
Nielsen, C.H., Sigurdsson, H.. 1981. Quantitative methods for electron microprobe analysis of sodium in natural and synthetic glasses. American Mineralogist 66. 547–552.Google Scholar
Ninkovich, D.. 1968. Pleistocene volcanic eruptions in New Zealand recorded in deep-sea sediments. Earth and Planetary Science Letters 4. 89–102.CrossRefGoogle Scholar
Rankin, P.C., Howorth, R., Whitten, J., Burke, A.S.. 1975. Comparison of two extraction techniques for volcanic glass. New Zealand Journal of Science 18. 103–107.Google Scholar
Seward, D.. 1974a. Age of New Zealand Pleistocene substages by fission-track dating of glass shards from tephra horizons. Earth and Planetary Science Letters 24. 242–248.CrossRefGoogle Scholar
Seward, D.. 1974b. Some Aspects of the Sedimentology of the Wanganui Basin, North Island, New Zealand. Unpublished PhD. thesis. Victoria University of Wellington.Google Scholar
Seward, D.. 1975. Fission-track ages of some tephras from Cape Kidnappers, Hawke's Bay, New Zealand. New Zealand Journal of Geology and Geophysics 18. 507–510.Google Scholar
Seward, D.. 1976. Tephrostratigraphy of the marine sediments in the Wanganui Basin, New Zealand. New Zealand Journal of Geology and Geophysics 19. 9–20.Google Scholar
Seward, D.. 1979. Comparison of zircon and glass fission-track ages from tephra horizons. Geology 7. 479–482.Google Scholar
Smith, D.W.G., Westgate, J.A.. 1969. Electron probe technique for characterising pyroclastic deposits. Earth and Planetary Science Letters 5. 313–319.Google Scholar
Sparks, R.S.J., Walker, G.P.L.. 1977. The significance of vitric-enriched airfall ashes associated with crystal-enriched ignimbrites. Journal of Volcanology and Geothermal Research 2. 329–341.CrossRefGoogle Scholar
Vucetich, C.G., Howorth, R.. 1976. Proposed definition of the Kawakawa Tephra, the c. 20,000-years B.P. marker horizon in the New Zealand region. New Zealand Journal of Geology and Geophysics 19. 43–50.CrossRefGoogle Scholar
Vucetich, C.G., Pullar, W.A.. 1969. Stratigraphy and chronology of late Pleistocene volcanic ash beds in central North Island, New Zealand. New Zealand Journal of Geology and Geophysics 12. 784–837.Google Scholar
Watkins, N.D., Huang, T.C.. 1977. Tephras in abyssal sediments east of North Island, New Zealand: Chronology, paleowind velocity, and paleoexplosivity. New Zealand Journal of Geology and Geophysics 20. 179–199.Google Scholar
Westgate, J.A., Fulton, R.J.. 1975. Tephrostratigraphy of Olympia interglacial sediments in south-central British Columbia, Canada. Canadian Journal of Earth Science 12. 489–502.Google Scholar