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An enriched mantle source for Italy's melilitite-carbonatite association as inferred by its Nd-Sr isotope signature

Published online by Cambridge University Press:  05 July 2018

F. Castorina ,
F. Stoppa ,
A. Cundari  and
M. Barbieri
F. Castorina*
Affiliation:
Dipartimento di Scienze della Terra, Università “La Sapienza”, P. le A. Moro, 5, 00185 Roma, Italy
F. Stoppa
Affiliation:
Dipartimento di Scienze della Terra, Università G. d'Annunzio, 66013 Chieti Scalo, Italy
A. Cundari
Affiliation:
Dipartimento di Geofisica e Vulcanologia, Università “Federico II”, Largo S. Marcellino, 10, 80100, Napoli, Italy
M. Barbieri
Affiliation:
Dipartimento di Scienze della Terra, Università “La Sapienza”, P. le A. Moro, 5, 00185 Roma, Italy
*
*E-mail: [email protected]
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Abstract

New Sr-Nd isotope data were obtained from Late Pleistocene carbonatite-kamafugite associations from the Umbria-Latium Ultra-Alkaline District of Italy (ULUD) with the aim of constraining their origin and possible mantle source(s). This is relevant to the origin and evolution of ultrapotassic (K/Na ≫2) and associated rocks generally, notably the occurrences from Ugandan kamafugites,Western Australian lamproites and South African orangeites. The selected ULUD samples yielded 87Sr/86Sr and 143Nd/144Nd ranging from 0.7100 to 0.7112 and from 0.5119 to 0.5121 respectively, similar to cratonic potassic volcanic rocks with higher Rb/Sr and lower Sm/Nd ratios than Bulk Earth. Silicate and carbonate fractions separated from melilitite are in isotopic equilibrium, supporting the view that they are cogenetic. The ULUD carbonatites yielded the highest radiogenic Sr so far reported for carbonatites. In contrast, sedimentary limestones from ULUD basement formations are lower in radiogenic Sr, i.e. 87Sr/86Sr = 0.70745–0.70735. The variation trend of ULUD isotopic compositions is similar to that reported for Ugandan kamafugites and Western Australian lamproites and overlaps the values for South African orangeites in the εSr-εNd diagram. A poor correlation between Sr/Nd and 87Sr/86Sr ratios in ULUD rocks is inconsistent with a mantle source generated by subduction-driven processes, while the negligible Sr and LREE in sedimentary limestones from the ULUD region fail to account for a hypothetical limestone assimilation process. The Nd model ages of 1.5–1.9 Ga have been inferred for a possible metasomatic event, allowing further radiogenic evolution of the source, a process which may have occurred in isolation until eruption time. While the origin of this component remains speculative, the Sr-Nd isotope trend is consistent with a simple mixing process involving an OIB-type mantle and a component with low εNd and high εSr.

Keywords

ItalyUmbriaLatiumcarbonatitesmelilititesSr-Nd isotopesenriched mantle
Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 4 , August 2000 , pp. 625 - 639
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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References

Bailey, D.K. (1993) Carbonate magmas. J. Geol. Soc., 150, 637–51.CrossRefGoogle Scholar
Barker, S.D. and Nixon, P.H. (1989) High-Ca, low-alkali carbonatite volcanism at Fort Portal, Uganda. Contrib. Mineral. Petrol., 103, 166–77.CrossRefGoogle Scholar
Bell, K. and Blenkinsop, J. (1987) Nd and Sr isotopic compositions of Eastern African carbonatites: implications for mantle heterogeneity. Geology, 15, 99–102.2.0.CO;2>CrossRefGoogle Scholar
Bell, K. and Blenkinsop, J. (1989) Neodymium and Strontium isotope geochemistry of carbonatites. Pp. 278–300 in Carbonatites: Genesis and Evolution (Bell, K., editor). Unwin-Hyman, London.Google Scholar
Cundari, A. (1973) Petrology of the leucite-bearing lavas in New South Wales. Geol. Soc. Austral., 20, 465–92.CrossRefGoogle Scholar
Cundari, A. (1980) Role of subduction in the genesis of leucite-bearing rocks: fact or fashion? Reply to A.D. Edgar's discussion paper. Contrib. Mineral. Petrol., 11, 423–34.Google Scholar
Cundari, A. and Ferguson, A.K. (1991) Petrogenetic relationship between melilitite and lamproite in the Roman Comagmatic Region: the lavas of San Venanzo and Cupaello. Contrib. Mineral. Petrol., 107, 343–57.CrossRefGoogle Scholar
Cundari, A. and O'Hara, M.J. (1976) Experimental study at atmospheric and high pressure of a mafic leucite from New South Wales, Australia. Nat. Envir. Res. Council publ. Ser. D, 6, 260–1.Google Scholar
Ellam, R.M., Hawkesworth, C.J., Menzies, M.A. and Rogers, N.W. (1989) The volcanism of Southern Italy: role of subduction and the relationship between potassic and sodic alkaline magmatism. J. Geophys. Res., 94, 4589–601.CrossRefGoogle Scholar
Ferguson, A.K. and Cundari, A. (1975) Petrological aspects and evolution of the leucite-bearing lavas from Bufumbira, South West Uganda. Contrib. Mineral. Petrol., 50, 25–46.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
Frey, F.A., Green, D.H. and Roy, S.D. (1978) Integrated models of basalt petrogenesis: a study of quartz tholeiites to olivine melilites from Southeastern Australia utilising geochemical and experimental petrological data. J. Petrol., 19, 463–513.CrossRefGoogle Scholar
Gallo, F., Giammetti, F., Venturelli, G. and Vernia, L. (1984) The kamafugitic rocks of San Venanzo and Cupaello, central Italy. Neues Jahrb. Mineral. Abh., 48, 198–210.Google Scholar
Hawkesworth, C.J., Fraser, K.J. and Rogers, N.W. (1985) Kimberlites and lamproites: extreme products of mantle enrichment processes. Trans. Geol. Soc. S. Afr., 88, 439–47.Google Scholar
Henderson, P. (1982) Inorganic Geochemistry, Pergamon Press, Oxford.Google Scholar
Irving, A.J. (1978) A review of experimental studies of crystal/liquid trace element partitioning. Geochim. Cosmochim. Acta, 42, 743–70.CrossRefGoogle Scholar
Jones, A.P., Kostoula, T., Stoppa, F. and Woolley, A.R. (2000) Petrography and mineral chemistry of mantle xenoliths in a carbonate-rich melilititic tuff from Mt. Vulture volcano, southern Italy. Mineral. Mag., 64, 593–613.CrossRefGoogle Scholar
Koepnick, R.B., Burke, W.H., Denison, R.E., Hetherington, A., Nelson, H.F., Otto, J.B. and Waite, L.E. (1985) Construction of the seawater 87Sr/86Sr curve for the Cenozoic and Cretaceous: supporting data. Chem. Geol., (Isotope Geoscience Section), 58, 55–81.CrossRefGoogle Scholar
Laurenzi, M.A.F., Stoppa, F. and Villa, I.M. (1994) Eventi ignei monogenici e depositi piroclastici nel Distretto Ultra-alcalino Umbro-Laziale (ULUD): revisione, aggiornamento e comparazione dei dati cronologici. Plinius, 12, 61–5.Google Scholar
Lavecchia, G. and Stoppa, F. (1996) The tectonic significance of Italian magmatism: an alternative view. Terra Nova, 8, 435–46.CrossRefGoogle Scholar
Lloyd, F.E. and Bailey, D.K. (1975) Light element metasomatism of the continental mantle: the evidence and the consequences. Phys. Chem. Earth, 9, 389–416.CrossRefGoogle Scholar
Ludwig, K.R. (1994) Analyst version 2.20: a computer program for control of a thermal-ionization, single collector mass-spectrometer. U.S. Department of the Interior Geological Survey, Open File, Report 92–543.Google Scholar
McKenzie, D. (1989) Some remarks on the movement of small melt fractions in the mantle. Earth Planet. Sci. Lett., 95, 53–72 CrossRefGoogle Scholar
McKenzie, D. and O'Nions, R.K. (1991) Partial melt distributions from inversion of rare earth element concentrations. J. Petrol., 32, 1021–91.CrossRefGoogle Scholar
Menzies, M. (1987) Alkaline rocks and their inclusions: a window on the Earth's interior. Pp. 15–28 in: Alkaline Igneous Rocks (Fitton, J.G. and Upton, B.G.J., editors). Geological Society of London, Special Publication, 30.Google Scholar
Mitchell, R.H. (1995) Kimberlites, Orangeites and Related Rocks. Plenum Press, New York.CrossRefGoogle Scholar
Mitchell, R.H. and Bergman, S.C. (1991) Petrology of Lamproites. Plenum Publishing Corporation, New York.CrossRefGoogle Scholar
Mitchell, R.H., Platt, R.G. and Downey, M. (1987) Petrology of lamproites from Smoky Butte, Montana. J. Petrol., 28, 645–77.CrossRefGoogle Scholar
Nelson, D.R. (1992) Isotopic characteristics of potassic rocks: evidence for the involvement of subducted sediments in magma genesis. Lithos, 28, 403–20.CrossRefGoogle Scholar
Peccerillo, A. (1985) Roman Comagmatic Province (Central Italy): evidence for subduction related magma genesis. Geology, 13, 103–6.2.0.CO;2>CrossRefGoogle Scholar
Peccerillo, A. (1995) Mafic ultrapotassic magmas in Central Italy: geochemical and petrochemical evidence against primary composition. Mineral. Petrograf. Acta, 37, 229–45.Google Scholar
Peccerillo, A., Poli, G. and Serri, G. (1988) Petrogenesis of orenditic and kamafugitic rocks from Central Italy. Canad. Mineral., 26, 45–65.Google Scholar
Philpotts, J.A. and Schnetzler, C.C. (1970) Phenocrystmatrix partition coefficients for K, Rb, Sr and Ba with application to anorthosite and basalt genesis. Geochim. Cosmochim. Acta, 34, 307–22.CrossRefGoogle Scholar
Ringwood, A.E., Kesson, S.E., Hibberson, W. and Ware, N. (1992) Origin of kimberlites and related magmas. Earth Planet. Sci. Lett., 113, 521–38.CrossRefGoogle Scholar
Serri, G., Innocenti, F. and Manetti, P. (1993) Geochemical and petrological evidence of the subduction of delaminated adriatic continental lithosphere and the genesis of the Neogene Quaternary magmatism of Central Italy. Tectonophysics, 223, 117–47.CrossRefGoogle Scholar
Shaw, D.M. (1970) Trace element behaviour during anatexis. Geochim. Cosmochim. Acta, 42, 933–43.CrossRefGoogle Scholar
Stoppa, F. (1988) L'euremite di Colle Fabbri (Spoleto): un litotipo ad affinità carbonatitica in Italia. Boll. Soc. Geol. Italiana, 107, 239–48.Google Scholar
Stoppa, F. (1996) The San Venanzo maar and tuff ring, Umbria, Italy: eruptive behaviour of a carbonatite-melilitite volcano. Bull. Volcanol., 57, 563–77.Google Scholar
Stoppa, F. and Cundari, A. (1995) A new Italian carbonatite occurrence at Cupaello (Rieti) and its genetic significance. Contrib. Mineral. Petrol., 122, 275–88.CrossRefGoogle Scholar
Stoppa, F. and Lavecchia, G. (1992) Late Pleistocene ultra-alkaline magmatic activity in the Umbria Latium region (Italy): An overview. J. Volcanol. Geotherm. Res., 52, 227–93.CrossRefGoogle Scholar
Stoppa, F. and Lupini, L. (1993) Mineralogy and petrology of the Polino monticellite calcite carbonatite (Central Italy). Mineral. Petrol., 49, 213–31.CrossRefGoogle Scholar
Stoppa, F. and Principe, C. (1997) Eruption styles and petrology of a new carbonatitic suite from the Mt. Vulture (Southern Italy): the Monticchio Lakes formation. J. Volcanol. Geotherm. Res. In press.CrossRefGoogle Scholar
Stoppa, F. and Woolley, A.R. (1997) The Italian carbonatites: field occurrence, petrology and regional significance. Mineral. Petrol., 19, 43–67.CrossRefGoogle Scholar
Tainton, K.M. (1992) The petrogenesis of group-2 kimberlites and lamproites from the northern Cape province, South Africa. Ph. D. thesis, Univ. Cambridge, UK.Google Scholar
Vollmer, R. (1976) Rb-Sr and U-Th-Pb systematics of alkaline rocks: the alkaline rocks from Italy. Geochim. Cosmochim. Acta, 40, 283–95.CrossRefGoogle Scholar
Vollmer, R. (1989) The origin of the Italian potassic magmas. A discussion contribution. Chem. Geol., 74, 229–39.CrossRefGoogle Scholar
Wood, D.A., Joron, J.L. and Treuil, M. (1979) Elemental and Sr isotope variation in basic lavas from Iceland and the surrounding ocean floor. Contrib. Mineral. Petrol., 70, 319–33.CrossRefGoogle Scholar