Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-08T07:25:28.817Z Has data issue: false hasContentIssue false
  • English
  • Français

Iron-rich and iron-poor prehnites from the Way Linggo epithermal Au-Ag deposit, southwest Sumatra, and the Heber geothermal field, California

Published online by Cambridge University Press:  05 July 2018

R. S. Wheeler ,
P. R. L. Browne  and
K. A. Rodgers
R. S. Wheeler
Affiliation:
Department of Geology, University of Auckland, Private Bag 92019, Auckland, New Zealand
P. R. L. Browne
Affiliation:
Department of Geology, University of Auckland, Private Bag 92019, Auckland, New Zealand Geothermal Institute, University of Auckland, Private Bag 92019, Auckland, New Zealand
K. A. Rodgers*
Affiliation:
Department of Geology, University of Auckland, Private Bag 92019, Auckland, New Zealand Australian Museum, Sydney, Australia
*
*E-mail: ka.rodgers@auckland.ac.nz
Get access Rights & Permissions [Opens in a new window]

Abstract

Electron microprobe analyses of prehnites from the Way Linggo low-sulphidation epithermal Au-Ag deposit of southern Sumatra, show that the mole fraction of octahedral Fe3+, expressed as Fe3+/(Fe3++AlVI), ranges from 0.0 to ~0.6, the higher values being among the most iron-rich reported for prehnite in a hydrothermal environment. Prehnites from a diabase sill in the Heber geothermal field of California have mole fractions of octahedral Fe3+ ranging from 0.03 to 0.3. The Way Linggo prehnites formed below 220°C, some 20–30°C lower than those at the Heber field; the lower crystallization temperatures perhaps enhanced the opportunity for Fe3+ to substitute in octahedral sites. In both occurrences, prehnite predates late-stage calcite, consistent with the need for waters depositing prehnite to have aCO2 <0.01 moles. At higher CO2 activities the stability field of calcite would swamp the range of aCa2+/aH+ values appropriate for crystallizing prehnite. Consequently, the presence of prehnite in a hydrothermal environment primarily indicates that degassing of the hydrothermal fluid in CO2 occurred prior to deposition.

Keywords

prehniteWay Linggo epithermal depositHeber geothermal fieldSumatraCalifornia
Type
Research Article
Information
Mineralogical Magazine , Volume 65 , Issue 3 , June 2001 , pp. 397 - 406
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Allison, M.L. (1990) Remote detection of active faults using borehole breakouts in the Heber geothermal field, Imperial Valley, California. Trans. Geotherm. Res. Council, 14, 1359–64.Google Scholar
Bird, D.K. and Helgeson, H.C. (1981) Chemical interactions of aqueous solutions with epidote-feldspar mineral assemblages in geologic systems. II. Equilibrium constraints in metamorphic/geothermal processes. Amer. J. Sci., 281, 576–614.CrossRefGoogle Scholar
Bird, D.K., Schiffman, P., Elders, W.A., Williams, A.E. and McDowell, S.D. (1984) Calc-silicate mineralization in active geothermal systems. Econ. Geol., 79, 671–95.CrossRefGoogle Scholar
Bogie, I. and Lawless, J.V. (1987) Controls on the hydrology of large volcanically hosted geothermal systems: implications for exploration for epithermal mineral deposits. Pp. 57–60 in: Proceedings, 1987 PACRIM Congress, Australian Institute of Mining and Metallurgy, Carlton, Victoria. Google Scholar
Browne, P.R.L. (1977) Occurrence of hydrothermal alteration of diabase, Heber geothermal field, Imperial Valley, California. Preliminary Report, University of California Riverside, Institute of Geophysics Planetary Physics Report 77/9, 61 pp.Google Scholar
Browne, P.R.L. (1978) Hydrothermal alteration in active geothermal fields. Ann. Rev. Earth Planet. Sci., 6, 229–50.CrossRefGoogle Scholar
Browne, P.R.L. and Ellis, A.J. (1970) The Ohaaki-Broadlands geothermal area, New Zealand: mineralogy and related geochemistry. Amer. J. Sci., 269, 97–131.CrossRefGoogle Scholar
Browne, P.R.L., Courtney, S.F. and Wood, C.P. (1989) Formation rates of calc-silicate minerals deposited inside drillhole casing, Ngatamariki geothermal field, New Zealand. Amer. Mineral., 74, 759–63.Google Scholar
Ellis, A.J. and Mahon, W.A.J. (1977) Chemistry and Geothermal Systems. Academic Press, London.Google Scholar
Gianelli, G., Mekuria, N., Battaglia, S., Chersicla, A., Garofalo, P., Ruggieri, G., Manganelli, M. and Gabregziabher, Z. (1998) Water-rock interaction and hydrothermal mineral equilibria in the Tendaho geothermal system. J. Volcanol. Geotherm. Res., 86, 253–76.CrossRefGoogle Scholar
Hadi, J. (1998) A hydrothermal alteration study to assess temperature and overprinting from S-1 Exploration Well – North Darajat field, Indonesia (abstract). P. 452 in: Proceedings 20th New Zealand Geothermal Workshop. Google Scholar
Hochstein, M.P. and Browne, P.R.L. (1999) Surface manifestations of geothermal systems with volcanic heat sources. Pp. 835–55 in: Encyclopedia of Volcanology (Sigurdsson, H., editor). Academic Press, New York.Google Scholar
Hochstein, M.P. and Healy, J. (1973) Horizontal flow in geothermal systems. N. Zealand J. Hydrol., 12, 71–82.Google Scholar
Kacandes, G.H. and Grandstaff, D.E. (1989) Differences between geothermal and experimentally derived fluids: How well do hydrothermal experiments model the composition of geothermal reservoir fluids? Geochim. Cosmochim. Acta, 53, 343–58.CrossRefGoogle Scholar
Kasbani, , Browne, P.R.L., Johnstone, R.D., Kahsai, K., Utami, P. and Wangge, A. (1997) Subsurface hydrothermal alteration in the Ulumbu geothermal field, Flores, Indonesia. Pp. 465–71 in: Proceedings 22nd Geothermal Workshop, Stanford.Google Scholar
Kristmansdottir, H. and Tómasson, J. (1976) Hydrothermal alteration in Icelandic geothermal fields. Science in Iceland (Scientia Islandica), 5, 161–76.Google Scholar
Lawless, J.V., White, P.J., Bogie, I. and Andaus, M.J. (1995) Tectonic features of Sumatra and New Zealand in relation to active and fossil hydrothermal systems: a comparison. Pp. 311–6 in: Proceedings of PACRIM Congress (Mauk, J.L. and George, J.A. St, editors). Australasian Institute of Mining and Metallurgy Publication Series 9/95.Google Scholar
Liou, J.G., Kim, H.S. and Maruyama, S. (1983) Prehnite-epidote equilibria and their petrologic applications. J. Petrol., 24, 321–42.CrossRefGoogle Scholar
Lippman, M.J. and Bodvarsson, G.S. (1983) A modelling study of the natural state of the Heber geothermal field, California. Trans. Geotherm. Res. Council, 7, 441–7.Google Scholar
Matsueda, M. (1975) [Iron-rich prehnite from the skarn of Sampo mine, Okayama Prefecture, Japan.]. Science Reports of the Department of Geology, Kyushu University, 12, 91–100 (in Japanese).Google Scholar
Moore, J.N., Powell, T.S., Brunton, C.J., Norman, D.I. and Heizler, M.T. (1998) Thermal and chemical evolution of the Tiwi geothermal system, Philippines. Pp. 671–4 in: Water-Rock Interaction (Archart, G.B. and Hulston, J.R., editors). Proceedings 9th Water-Rock Interaction International Symposium, Taupo, New Zealand.Google Scholar
Ostera, H.A., Do Campo, M.D. and Nunez, H. (1992) Hallazgo de manifestaciones minerales epitermales en el grupo volcanico, Peninsula Antarctica, Baiha Botanica, Peninsula. Actas del Congresso Geologico Argentino, 11, 15–8.Google Scholar
Oyarzun, R., Ortega, L., Sierra, J., Lunar, R. and Oyarzun, J. (1998) Cu, Mn and Ag mineralization in the Quebrada Marquesa Quadrangle, Chile – The Talcuna and Aqueros Districts. Mineral. Deposita, 33, 547–59.CrossRefGoogle Scholar
Parry, W.T. (1998) Fault-fluid compositions from fluidinclusion observations and solubilities of fracturesealing minerals. Tectonophysics, 290, 1–26.CrossRefGoogle Scholar
Reyes, A.G. (1990) Petrology of Philippine geothermal systems and the application of alteration mineralogy of their assessment. J. Volcanol. Geotherm. Res., 43, 279–309.CrossRefGoogle Scholar
Salveson, J.O. and Cooper, A.M. (1979) Exploration and development of the Heber Geothermal Field, Imperial Valley, California. Trans. Geotherm. Res. Council, 3, 605–8.Google Scholar
Simmons, S.F. and Christenson, B.W. (1994) Origins of calcite in a boiling geothermal system. Amer. J. Sci., 294, 361–400.CrossRefGoogle Scholar
Steiner, A. (1977) The Wairakei geothermal area, North Island, New Zealand: Its subsurface geology and hydrothermal rock alteration. N. Zealand Geol. Surv. Bull., 90, 136 pp.Google Scholar
Utami, P. and Browne, P.R.L. (1999) Subsurface hydrothermal alteration in the Kamojang geothermal field, West Java, Indonesia. Pp. 383–90 in: Proceedi ngs 24th Workshop on Geothermal Reservoir Engineering, Stanford.Google Scholar
Wang, N.D. and Paniagua, A. (1996) Fettelite, a new Hg-sulphosalt mineral from Odenwald. Neues Jahrb. Mineral. Mon., 313–320.Google Scholar
Youngman, K. (1984) Hydrothermal alteration and fluid-rock interaction in the El Tatio geothermal field, Antofagasta Province, Chile. Unpubl. MSc. thesis, Univ. Auckland, New Zealand.Google Scholar