Abstract
Scapolites are pervasive rock-forming aluminosilicates that are found in metamorphic, igneous, and hydrothermal environments; nonetheless, the stability field of Cl-rich scapolite is not well constrained. This experimental study investigated two reactions involving Cl-rich scapolite. First, the anhydrous reaction 1 of plagioclase + halite + calcite to form scapolite [modeled as: 3 plagioclase (Ab80An20) + 0.8 NaCl + 0.2 CaCO3 = scapolite (Ma80Me20)] was investigated to determine the effect of the Ca-rich meionite (Me = Ca4Al6Si6O24CO3) component on the Na end-member marialite (Ma = Na4Al3Si9O24Cl). Second, the effect of water on this reaction was investigated using the hydrothermally equivalent reaction 2, H2O + scapolite (Ma80Me20) = 3 plagioclase (Ab80An20) + CaCO3 + liquid, where the liquid is assumed to be a saline-rich hydrous-silicate melt. Experiments were conducted with synthetic phases over the range of 500–1030 °C and 0.4–2.0 GPa. For reaction 1, intermediate composition scapolite shows a wide thermal stability and is stable relative to plagioclase + halite + calcite at temperatures above 750 °C at 0.4 GPa and 760 °C at 2.0 GPa. For reaction 2, intermediate scapolite appears to be quite tolerant of water; it forms at a minimum bulk salinity [XNaCl = molar ratio of NaCl/(NaCl+H2O)] of the brine of approximately 0.2 XNaCl at 830 and 680 °C at pressures of 2.0 and 1.5 GPa, respectively. Based on the study done by Almeida and Jenkins (2017), pure marialite is very intolerant of water when compared to intermediate composition scapolite. Compositional changes in the scapolite and plagioclase were characterized by X‑ray diffraction and electron microprobe analysis and found to shift from the nominal bulk compositions to the observed compositions of Ma85Me15 for scapolite and to Ab91An09 for plagioclase. These results were used to model the phase equilibria along the marialite-meionite join in temperature-composition space. This study demonstrates that a small change in the scapolite composition from end-member marialite to Ma85Me15 expands the stability field of marialite significantly, presumably due to the high entropy of mixing in scapolite, as well as increases its tolerance to water. This supports the much more common presence of intermediate scapolites in hydrothermal settings than either end-member meionite or marialite as is widely reported in the literature.
Acknowledgments and Funding
The manuscript was much improved by the careful reviews of J. Filiberto and an anonymous reviewer and the editorial handling of S. Penniston-Dorland. The authors are grateful to David Collins, who assisted with the electron microprobe analyses. Financial support for this study came from NSF grant EAR-1347463 to D.M.J.
References cited
Almeida, K.M.F., and Jenkins, D.M. (2017) Stability field of the Cl-rich scapolite marialiate. American Mineralogist, 102, 2484–2493.10.2138/am-2017-6132Search in Google Scholar
Alt, J.C. (1995) Subseafloor processes in mid-ocean ridge hydrothermal systems. In S.E. Humphris, R.A. Zierenberg, L.S. Mullineaux, and R.E. Thomson, Eds., Seafloor Hydrothermal Systems: Physical, Chemical, Biological, and Geological Interactions, p. 85–114. Geophysical Monograph 91, American Geophysical Union, Washington, D.C.10.1029/GM091p0085Search in Google Scholar
Aranovich, L.Y., and Newton, R.C. (1996) H2O activity in concentrated NaCl solutions at high pressures and temperatures measured by the brucite-periclase equilibrium. Contributions to Mineralogy and Petrology, 125, 200–212.10.1007/s004100050216Search in Google Scholar
Baker, J., and Newton, R.C. (1995) Experimentally determined activity-composition relations for Ca-rich scapolite in the system CaAl2Si2O8-NaAlSi3O8-CaCO3 at 7 kbar. American Mineralogist, 80, 744–751.10.2138/am-1995-7-811Search in Google Scholar
Benisek, A., Kroll, H., Cemič, L., Kohl, V., Breit, U., and Heying, B. (2003) Enthalpies in (Na,Ca)- and (K,Ca)-feldspar binaries: a high-temperature solution calorimetric study. Contributions to Mineralogy and Petrology, 145, 119–129.10.1007/s00410-002-0436-8Search in Google Scholar
Boivin, P., and Camus, G. (1981) Igneous scapolite-bearing associations in the Chaine des Puys, Massif Central (France) and Atakor (Hoggar, Algeria). Contributions to Mineralogy and Petrology, 77, 365–375.10.1007/BF00371565Search in Google Scholar
Ellis, D.E. (1978) Stability and phase equilibria of chloride and carbonate bearing scapolites at 750°C and 4000 bar. Geochimica et Cosmochimica Acta, 42, 1271–1281.10.1016/0016-7037(78)90121-7Search in Google Scholar
Eugster, H.P., and Prostka, H.J. (1960) Synthetic scapolites. Geological Society of America, 71, 1859–1860.Search in Google Scholar
Evans, B.W., Shaw, D.M., and Haughton, D.R. (1969) Scapolite stoichiometry. Contributions to Mineralogy and Petrology, 24, 293–305.10.1007/BF00371272Search in Google Scholar
Filiberto, J., Treiman, A.H., Giesting, P.A., Goodrich, C.A., and Gross, J. (2014) High-temperature chlorine-rich fluid in the martian crust: A precursor to habitability. Earth and Planetary Science Letters, 401, 110–115.10.1016/j.epsl.2014.06.003Search in Google Scholar
Fontaine, F.J., Wilcock, W.S.D., and Butterfield, D.A. (2007) Physical controls on the salinity of mid-ocean ridge hydrothermal vent fluids. Earth and Planetary Science Letters, 257, 132–145.10.1016/j.epsl.2007.02.027Search in Google Scholar
Giblin, L.E., Blackburn, W.H., and Jenkins, D.M. (1993) X‑ray continuum discrimination technique for the energy dispersive analysis of fine particles. Analytical Chemistry, 65, 3576–3580.10.1021/ac00072a008Search in Google Scholar
Goldsmith, J.R. (1976) Scapolites, granulites, and volatiles in the lower crust. Geological Society of America, 87, 161–168.10.1130/0016-7606(1976)87<161:SGAVIT>2.0.CO;2Search in Google Scholar
Goldsmith, J.R., and Jenkins, D.M. (1985) The high-low albite relations revealed by reversal of degree of order at high pressures. American Mineralogist, 70, 911–923.Search in Google Scholar
Goldsmith, J.R., and Newton, R.C. (1977) Scapolite-plagioclase stability relations at high pressures and temperatures in the system NaAlSi3O8-CaAl2Si2O8-CaCO3- CaSO4 American Mineralogist, 62, 1063–1081.Search in Google Scholar
Graziani, G., and Lucchesi, S. (1982) The thermal behavior of scapolites. American Mineralogist, 67, 1229–1241.Search in Google Scholar
Hammerli, J., Spandler, C., Oliver, N.H.S., and Rusk, B. (2014) Cl/Br of scapolite as a fluid tracer in the earth’s crust: insights into fluid sources in the Mary Kathleen Fold Belt, Mt. Isa Inlier, Australia. Journal of Metamorphic Geology, 32, 93–112.10.1111/jmg.12060Search in Google Scholar
Hammerli, J., Kemp, A.I.S., Barrett, N., Wing, B.A., Roberts, M., Arculus, R. J., Boivin, P., Nude, P.M., and Rankenburg, K. (2017) Sulfur isotope signatures in the lower crust: A SIMS study on S-rich scapolite of granulites. Chemical Geology, 454, 45–66.10.1016/j.chemgeo.2017.02.016Search in Google Scholar
Hassan, I., and Buseck, P.R. (1988) HRTEM characterization of scapolite solid solutions. American Mineralogist, 73, 119–134.Search in Google Scholar
Holland, T. J.B., and Powell, R. (2011) An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids. Journal of Metamorphic Geology, 29, 333–383.10.1111/j.1525-1314.2010.00923.xSearch in Google Scholar
Jenkins, D.M., and Corona, J.-C. (2006) The role of water in the synthesis of glaucophane. American Mineralogist, 91, 1055–1068.10.2138/am.2006.2014Search in Google Scholar
Johnson, D.A., and Barton, M.D. (2000a) Field trip day four: Buena Vista Hills, Humboldt Mafic Complex, Western Nevada. Society of Economic Geologists Guidebook Series, 32, 145–162.Search in Google Scholar
Johnson, D.A., and Barton, M.D. (2000b) Time-space development of an external brine dominated, igneous-driven hydrothermal system: Humboldt mafic complex, western Nevada. Society of Economic Geologists Guidebook Series, 32, 127–143.Search in Google Scholar
Johnson, E.L., Goergen, E.T., and Fruchey, B.L. (2004) Right lateral oblique slip movements followed by post-Ottawan (1050–1020 Ma) orogenic collapse along the Carthage-Colton shear zone: Date from the Dana Hill metagabbro body, Adirondack Mountains, New York. In Tollo, R.P., Corriveau, L., McLel-land, J., and Bartholomew, M. J., Eds., Proterozoic Tectonic Evolution of the Grenville Orogeny in North America, 197, p. 357–378. Geological Society of America Memoir, Boulder, Colorado.10.1130/0-8137-1197-5.357Search in Google Scholar
Katongo, C., Koller, F., Ntaflos, T., Koeberl, C., and Tembo, F. (2011) Occurrence and origin of scapolite in the Neoproterozoic Lufilian-Zambezi belt, Zambia: Evidence/role of brine-rich fluid infiltration during regional metamorphism. In J. Ray, G. Sen, and B. Ghosh, Eds., Topics in Igneous Petrology, p. 449–473. Springer. DOI: 10.1007/978-90-481-9600-510.1007/978-90-481-9600-5Search in Google Scholar
Kendrick, M.A., Arculus, R.J., Danyushevsky, L.V., Kamenetsky, V.S., Woodhead, J.D., and Honda, M. (2014) Subduction-related halogens (Cl, Br, and I) and H2O in magmatic glasses from Southwest Pacific backarc basins. Earth and Planetary Science Letters, 400, 165–176.10.1016/j.epsl.2014.05.021Search in Google Scholar
Kerrick, D.M., and Darken, L.S. (1975) Statistical thermodynamic models for ideal oxide and silicate solid solutions, with application to plagioclase. Geochimica et Cosmochimica Acta, 39, 1431–1442.10.1016/0016-7037(75)90122-2Search in Google Scholar
Kroll, H., and Ribbe, P.H. (1980) Determinative diagrams for Al,Si ordering in plagioclases. American Mineralogist, 65, 449–457.Search in Google Scholar
Kullerud, K., and Erambert, M. (1999) Cl-scapolite, Cl-amphibole, and plagioclase equilibria in ductile shear zones at Nusfjord, Lofoten, Norway: Implications for fluid compositional evolution during fluid-mineral interaction in the deep crust. Geochimica et Cosmochimica Acta, 63, 3829–3844.10.1016/S0016-7037(99)00150-7Search in Google Scholar
Larson, A.C., and Von Dreele, R.B. (2000) General Structure Analysis System (GSAS), Los Alamos National Lab Report LAUR 86-748.Search in Google Scholar
Lieftink, D.J., Nijland, T.G., and Maijer, C. (1993) Cl-rich scapolite from Odegardens Verk, Bamble, Norway. Norsk Geologisk Tidsskrift, 73, 55–57.Search in Google Scholar
Lovering, J.F., and White, A.J.R. (1964) The significance of primary scapolite in granulitic inclusions from deep-seated pipes. Journal of Petrology, 5, 195–218.10.1093/petrology/5.2.195Search in Google Scholar
Makhluf, A.R., Newton, R.C., and Manning, C.E. (2016) Hydrous albite magmas at lower crustal pressure: new results on liquidus H2O content, solubility, and H2O activity in the system NaAlSi3O8–H2O–NaCl at 1.0 GPa. Contributions to Mineralogy and Petrology, 171, 75, 18pp. DOI: 10.1007/s00410-016-1286-010.1007/s00410-016-1286-0Search in Google Scholar
Mora, C.I., and Valley, J.W. (1989) Halogen-rich scapolite and biotite: Implications for metamorphic fluid-rock interaction. American Mineralogist, 74, 721–737.Search in Google Scholar
Newton, R.C., and Goldsmith, J.R. (1976) Stability of the end-member scapolites: 3NaAlSi3O8·NaCl, 3CaAl2Si2O8·CaCO3 3CaAl2Si2O8·CaSO4. Zeitschrift für Kristallographie, 143, 333–353.10.1524/zkri.1976.143.jg.333Search in Google Scholar
Newton, R.C., Charlu, T.V., and Kleppa, O.J. (1980) Thermochemistry of the high structural state plagioclases. Geochimica et Cosmochimica Acta, 44, 933–941.10.1016/0016-7037(80)90283-5Search in Google Scholar
Oliver, N.H.S., Wall, V.J., and Cartwright, I. (1992) Internal control of fluid compositions in amphibolite-facies scapolitic calc-silicates, Mary Kathleen, Australia. Contributions to Mineralogy and Petrology, 111, 94–112.10.1007/BF00296581Search in Google Scholar
Orville, P.M. (1975) Stability of scapolite in the system Ab-An-NaCl-CaCO3 at 4 kb and 750°C. Geochimica et Cosmochimica Acta, 39, 1091–1105.10.1016/0016-7037(75)90052-6Search in Google Scholar
Oterdoom, W.H. (1979) Plagioclase-scapolite-calcite phase relations in high metamorphic argillaceous limestones. Schweizerische Mineralogische und Petrographische Mitteilungen, 59, 417–422.Search in Google Scholar
Oterdoom, W.H., and Gunter, W.D. (1983) Activity models for plagioclase and CO3·scapolites – An analysis of field and laboratory data. American Journal of Science, 283-A, 255–282.Search in Google Scholar
Prewitt, C.T., Sueno, S., and Papike, J.J. (1976) The crystal structures of high albite and monalbite at high temperatures. American Mineralogist, 61, 1213–1225.Search in Google Scholar
Price, J.G. (1985) Ideal site mixing in solid solutions, with an application to two-feldspar geothermometry. American Mineralogist, 70, 696–701.Search in Google Scholar
Rebbert, C.R., and Rice, J.M. (1997) Scapolite-plagioclase exchange: Cl-CO3 scapolite solution chemistry and implications for peristerite plagioclase. Geochimica et Cosmochimica Acta, 61, 555–567.10.1016/S0016-7037(96)00362-6Search in Google Scholar
Reed, S. J.B. (1996) Electron Microprobe Analysis and Scanning Electron Microscopy in Geology. Cambridge University Press.Search in Google Scholar
Sokolova, E., and Hawthorne, F.C. (2008) The crystal chemistry of the scapolite-group minerals. I. Crystal structure and long-range order. Canadian Mineralogist, 46, 1527–1554.10.3749/canmin.46.6.1527Search in Google Scholar
Sokolova, E.V., Kabalov, Y.K., Sherriff, B.L., Teertstra, D.K., Jenkins, D.M., Kunath-Fandrei, G., Goetz, S., and Jäger, C. (1996) Marialite: Rietveld-structure refinement and 29Si MAS and 27Al satellite transition NMR spectroscopy. Canadian Mineralogist, 34, 1039–1050.Search in Google Scholar
Solberg, T.N., Abrecht, J., and Hewitt, D.A. (1981) Graphical procedures for the refinement of electron microprobe analysis of fine-grained particles. In R.H. Geiss, Ed., Microbeam Analysis, p. 160–162. San Francisco Press.Search in Google Scholar
Teertstra, D.K., and Sherriff, B.L. (1997) Substitutional mechanisms, compositional trends and the end-member formulae of scapolite. Chemical Geology, 136, 233–260.10.1016/S0009-2541(96)00146-5Search in Google Scholar
Teertstra, D.K., Schindler, M., Sherriff, B.L., and Hawthorne, F.C. (1999) Silvialite, a new sulfate-dominant member of the scapolite group with an Al-Si composition near the I4/m-P42/n phase transition. Mineralogical Magazine, 63, 321–329.10.1180/002646199548547Search in Google Scholar
Vanko, D.A., and Bishop, F.C. (1982) Occurrence and origin of marialitic scapolite in the Humboldt lopolith, N.W. Nevada. Contributions to Mineralogy and Petrology, 81, 277–289.10.1007/BF00371682Search in Google Scholar
Yoshino, T., and Satish-Kumar, M. (2001) Origin of scapolite in deep-seated metagabbros of the Kohistan Arc, NW Himalayas. Contributions to Mineralogy and Petrology, 140, 511–531.10.1007/s004100000207Search in Google Scholar
© 2019 Walter de Gruyter GmbH, Berlin/Boston