Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-24T03:58:03.286Z Has data issue: false hasContentIssue false

Strontian fluoro-magnesiohastingsite in Alban Hills lavas (Central Italy): constraints on crystallization conditions

Published online by Cambridge University Press:  05 July 2018

M. Gaeta*
Affiliation:
Dipartimento di Scienze della Terra, Universita̒ degli Studi ‘La Sapienza’, P. le Aldo Moro 5, I-00185 Roma, Italy
C. Freda
Affiliation:
Dipartimento di Scienze della Terra, Universita̒ degli Studi ‘La Sapienza’, P. le Aldo Moro 5, I-00185 Roma, Italy
*

Abstract

A magmatic calcic amphibole (M4Ca≥1.50) characterized by large Sr and F contents (SrO>1 wt.%, F>2.5 wt.%) is described. According to the crystal-chemical formula, the amphibole can be classified as a strontian fluoro-magnesiohastingsite and the presence of Sr cations in the A sites is suggested. The amphibole occurs in the groundmass of ultrapotassic lavas from the Alban Hills Volcanic District (Central Italy). This peculiar chemical composition is due to the lavas' groundmass compositional trend occurring under low silica-activity conditions. We suggest that the occurrence of F amphiboles allows us to consider the Alban Hills Volcanic District magmas to be as rich in F as other ultrapotassic magmas.

Type
Research Article
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

Baker, M.B. and Grove, T.L. (1985) Kinetic controls on pyroxene nucleation and metastable liquid lines of descent in a basaltic andesite. Amer. Mineral., 70, 279–87.Google Scholar
Barbieri, M., Mitsaki, V. and Penta, A. (1969) Una provincia geochimica ricca in stronzio: i Colli Albani. Contenuto in stronzio e fenomeni di zeolitizzazione delle piroclastiti. Per. Mineral., 38, 117–49.Google Scholar
Carmichael, I.S.E. (1967) The mineralogy and petrology of the volcanic rocks from the Leucite Hills, Wyoming. Contrib. Mineral. Petrol., 15, 24–66.CrossRefGoogle Scholar
Carroll, M.R. and Blank, J.G. (1997) The solubility of H2O in phonolitic melts. Amer. Mineral., 82, 549–56.CrossRefGoogle Scholar
Carroll, M.R. and Webster, J.D. (1994) Solubilities of sulfur, noble gases, nitrogen, chlorine, and fluorine in magmas. Pp. 230–79 in: Volatiles in Magmas (Carroll, M.R. and Holloway, J.H., editors). Reviews in Mineralogy, 30. Mineralogical society of America, Washington, D.C. CrossRefGoogle Scholar
Charles, R.W. (1977) The phase equilibria of intermediate compositions on the pseudobinary Na2CaMg5Si8O22(OH)2-Na2Fe5Si8O22(OH)2 . Amer. J. Sci., 277, 594–625.CrossRefGoogle Scholar
Dalpé, C. and Baker, D.R. (2000) Experimental investigation of large-ion-lithophile-element-, high- field-strength-element- and rare-earth-element-partitioning between calcic amphibole and basaltic melt: the effects of pressure and oxygen fugacity. Contrib. Mineral. Petrol., 140, 233–50.Google Scholar
Della Ventura, G. and Robert, J.-L. (1990) Synthesis, XRD and FTIR studies of strontium richterites. Eur. J. Mineral., 2, 171–5.CrossRefGoogle Scholar
Dolfi, D. and Trigila, R. (1988) Chemical relations between clinopyroxenes and coexisting glasses obtained from melting experiments on alkaline basic lavas. Rend. Soc. It. Mineral. Petrol., 43, 1101–10.Google Scholar
Droop, G.T.R. (1987) A general equation for estimating Fe3+ concentrations in ferromagnesian silicates and oxides from microprobe analyses, using stoichiometric criteria. Mineral. Mag., 51, 431–5.CrossRefGoogle Scholar
Edgar, A.D. and Charbonnau, H.E. (1991) Fluorinebearing phases in lamproites. Mineral. Petrol., 44, 125–49.CrossRefGoogle Scholar
Ewart, A. and Griffin, W.L. (1994) Application of proton-microprobe data to trace-element partitioning in volcanic rocks. Chem. Geol., 117, 251–84.CrossRefGoogle Scholar
Foley, S.F. (1985) The oxidation state of lamproitic magmas. Tschermaks Mineral. Petrol. Mitteil., 34, 217–38.CrossRefGoogle Scholar
Foley, S.F. (1989) Experimental constraints on phlogopite chemistry in lamproites. I. The effect of water activity and oxygen fugacity. Eur. J. Mineral., 1, 411–26.CrossRefGoogle Scholar
Foley, S.F., Taylor, W.R. and Green, D.H. (1986) The role of fluorine and oxygen fugacity in the genesis of the ultrapotassic rocks. Contrib. Mineral. Petrol., 94, 183–92.CrossRefGoogle Scholar
Foley, S.F., Venturelli, G., Green, D.H. and Toscani, L. (1987) The ultrapotassic rocks: characteristics, classification, and constraints for petrogenetic models. Earth Sci. Rev., 24, 81–134.CrossRefGoogle Scholar
Freda, C., Gaeta, M., Palladino, D.M. and Trigila, R. (1997) The Villa Senni Eruption (Alban Hills, Central Italy): the role of H2O and CO2 on the magma chamber evolution and on the eruptive scenario. J. Volcanol. Geotherm. Res., 78, 103–20.CrossRefGoogle Scholar
Gaeta, M. (1998) Petrogenetic implications of Basanidine in the Lionato Tuff (Colli Albani Volcanic District, Central Italy). Mineral. Mag., 62, 697–701.CrossRefGoogle Scholar
Gaeta, M., Fabrizio, G. and Cavarretta, G. (2000) F-phlogopites in the Alban Hills Volcanic District (Central Italy): Indications regarding the role of volatiles in magmatic crystallization. J. Volcanol. Geotherm. Res., 99, 179–93.CrossRefGoogle Scholar
Hawthorne, F.C., Oberti, R., Ungaretti, L. and Grice, J.D. (1996) A new hyper-calcic amphibole with Ca at the A site: fluor-canniloite from Pargas, Finland. Amer. Mineral., 81, 995–1002.CrossRefGoogle Scholar
Larsen, L.M. (1979) Distribution of REE and other trace elements between phenocrysts and peralkaline undersaturated magmas, exemplified by rocks from the Gardar igneous province, south Greenland. Lithos, 12, 303–15.CrossRefGoogle Scholar
Leake, B.E. and 21 others (1997) Nomenclature of the amphiboles: report of the sub-committee on amphiboles of the International Mineralogical Association, Commission on New Minerals and Minerals Names. Mineral. Mag., 61, 295–321.CrossRefGoogle Scholar
Mitchell, R.H. and Bergman, S.C. (1991) Petrology of Lamproites. Plenum Press, New York.CrossRefGoogle Scholar
Mottana, A. and Griffin, W.L. (1986) Crystal chemistry of two coexisting K-richterites from St. Marcel (Val d'Aosta, Italy). Amer. Mineral., 71, 1426–33.Google Scholar
Oberti, R., Sardone, N., Hawthorne, F.C., Raudsepp, M. and Turnock, A.C. (1995) Synthesis and crystal-structure refinement of synthetic fluor-pargasite. Canad. Mineral., 33, 25–31.Google Scholar
Palladino, D.M., Gaeta, M. and Marra, F. (2001) A large K-foiditic hydromagmatic eruption from the early activity of the Alban Hills Volcanic District, Italy. Bull. Volcanol., 63, 345–59.CrossRefGoogle Scholar
Peccerillo, A. (1998) Relationships between ultrapotassic and carbonate-rich volcanic rocks in central Italy: petrogenetic and geodynamic implications. Lithos, 43, 267–79.CrossRefGoogle Scholar
Robert, J.-L. (1976) Titanium solubility in synthetic phlogopite solid solutions. Chem. Geol., 17, 213–27.CrossRefGoogle Scholar
Robert, J.-L., Della Ventura, G., Raudsepp, M. and Hawthorne, F.C. (1993) Rietveld structure refinement of synthetic strontium-rich potassium-richterites. Eur. J. Mineral., 5, 199–206.CrossRefGoogle Scholar
Robert, J.-L., Della Ventura, G., Welch, M.D. and Hawthorne, F.C. (2000) The OH-F substitution in synthetic pargasite at 1.5 kbar, 850°C. Amer. Mineral., 85, 926–31.CrossRefGoogle Scholar
Schumacher, J.C. (1997) The estimation of ferric iron in electron microprobe analysis of amphiboles. Mineral. Mag., 61, 312–21.Google Scholar
Sokolova, E.V., Kabalov, Yu.K., McCammon, C., Schneider, J. and Konev, A.A. (2000) Cation partitioning in an unusual strontian potassicrichterite from Siberia: Rietveld structure refinement and Mossbauer spectroscopy. Mineral. Mag., 64, 19–23.CrossRefGoogle Scholar
Taddeucci, A. (1964) Il boro e il fluoro nelle regioni vulcaniche dei Colli Albani, del Cimino e di Vico. Per. Mineral., 33, 73–145.Google Scholar
Trigila, R., Agosta, E., Currado, C., De Benedetti, A.A., Freda, C., Gaeta, M., Palladino, D.M. and Rosa, C. (1995) Petrology. Pp. 95165 in: The Volcano of the Alban Hills (Trigila, R., editor), Rome.Google Scholar
Wagner, C. and Velde, D. (1986) The mineralogy of K-richterite-bearing lamproites. Amer. Mineral., 71, 17–37.Google Scholar