Summary
A chemical and mineralogical study of magmatic inclusions in the silica-rich rocks of the Tolfa-Ceriti-Manziana sector (Tuscan Province, Central Italy) shows that they can be grouped according to their degree of alkalinity. We distinguish: TCM latites (TCML) with an alkaline-potassic affinity; Ceriti latites (CL) with calc-alkaline affinity; and Manziana shoshonites and latites (MS-ML) with an affinity intermediate between alkaline and subalkaline. The latter are hybrid rocks originating from the mixing of two magmas with slightly different geochemical affinities.
These magmas may represent liquids derived by partial melting of a heterogeneous mantle, metasomatized by a crustal source. The most alkaline magmas (TCML) are associated with the largest degree of metasomatism which, if more pronounced, could lead to the production of the potassic magmas of the Roman Province.
Zusammenfassung
Eine chemische und mineralogische Untersuchung der magmatischen Einschlüsse in den sauren Gesteinen des Tolfa-Ceriti-Manziana Sektors (Toskanische Provinz, Zentralitalien) zeigt, daß sie nach dem Grad der Alkalinitdt unterteilt werden können. Wir unterscheiden TCM latite (TCML) mit einer Alkali-Kalium Affinität; Ceriti Latite (CL) mit einer kalkalkalischen Affinität und Manziana Shoshonite und Latite (MS-ML) mit einer Affinität die zwischen alkalisch und subalkalisch liegt. Die Letztgenannten sind Mischgesteine, die durch die Mischung zweier Magmen mit verschiedenen geochemischen Affinitäten entstanden sind.
Diese Magmen, die genetisch nicht mit den Wirtsgesteinen in Beziehung stehen, dürften Schmelzen repräsentieren, die auf teilweise Aufschmelzung eines heterogenen Mantels, der durch eine krustale Quelle metasomatisiert wurde, zurückgehen. Die am meisten alkalischen Magmen (TCML) sind mit dem höchsten Grad der Metasomatose assoziiert, der wiederum, wenn noch stärker entwickelt, zur Entstehung der kalireichen Magmen der römischen Provinz führen könnte.
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References
Bacon CR (1986) Magmatic inclusions in silicic and intermediate volcanic rocks. J Geophys Res 91 B6: 6091–6112
Barton M, Varekamp JC, Van Bergen MJ (1982) Complex zoning of clinopyroxenes in the lavas of Vulsini Latium, Italy: evidence for magma mixing. J Volcanol Geotherm Res 14: 361–388
Beccaluva L, Di Girolamo P, Serri G (1991) Petrogenesis and tectonic setting of the Roman Volcanic Province, Italy. Lithos 26: 191–221
Clausen C, Holm PM (1990) Origin of the acidic volcanics of the Toifa district, Tuscan province, Central italy: an elemental and Sr-isotopic study. Contrib Mineral Petrol 105: 403–411
De Rita D, Bertagnini A, Carboni G, Ciccacci S, De Filippo M, Faccenna C, Fredi P, Funiciello R, Landi P, Sciacca P, Vannucci N, Zarlenga F (1994) Geological-petrographical evolution of the Ceriti Mountains area (Latium, Central Italy). Mem Serv Geol It XLIX: 291–322
De Rita D, Bertagnini A, Carboni G, Ciccacci S, De Filippo M, Faccenna C, Fredi P, Funiciello R, Landi P, Rosa C, Zarlenga F (1995) Evoluzione geologico-petrografica dei Monti della Tolfa (in preparation)
Ferrara G, Leoni L, Macera P (1976) La distribuzione di Zr, La. e Ce nelle rocce magmatiche toscane. Rend Soc It Min Petr 32: 539–549
Ferrara G, Macera P, Valentinetti R (1975) Contenuti di U e Th nelle rocce della Provnca Magmatica Toscana. Parte I. Rend Soc It Min Petr 31: 209–219
Ferrara G, Petrini R, Serri G, Tonarini S (1989) Petrology and isotope-geochemistry of San Vincenzo rhyolites (Tuscany, Italy). Bull Volcanol 51: 379–388
Ferrara G, Taylor HP, Tonarini S, Turi B (1990) Isotopic evidences for phenocryst-matrix disequilibrium in the interaction between crustal and subcrustal magmas. I.C.O.G. 7, Canberra, September 1990. Geol Soc Australia 34
Franzini M, Leoni L, Saitta M (1975) Revisione di una metodologia analitica per fluorescenza-X basata sulla correzione completa degli effetti matrice. Rend Soc It Min Petr 31: 365–378
Giraud A, Dupuy C, Dostal J (1986) Behaviour of trace elements during magmatic processes in the crust: application to acidic rocks of Tuscany (Italy). Chem Geol 57: 269–288
Holm PM (1982) Mineral chemistry of perpotassic lavas of the Vulsiman District, Central Italy, the Roman Province. Mineral Mag 46: 379–386
Joron JL, Metrich N, Rosi M, Santacroce R, Sbrana A (1987) Chemistry and petrography. In:Santacroce R (ed) Somma-Vesuvius. CNR, Quaderni de “La Ricerca Scientifica” 114 8: 105–174
Le Bas MJ (1962) The role of aluminum in igneous clinopyroxenes with relation to their parentage. Am J Sci 260: 267–288
Le Bas MJ, Le Maitre RW, Streckeisen A, Zanettin B (1986) A chemical classification of volcanic rocks based on the total alkali-silica diagram. J Petrol 27: 745–750
Marinelli G (1961) Genesi e classificazione delle vulcaniti recenti toscane. Atti Soc Tosc Sci Nat A 68: 74–116
Marinelli G (1967) Genese des magmas du volcanisme plio-quaternary des Apennins. Geol Rundsch 57: 127–141
Metrich N, Santacroce R, Sauelli C (1988) Ventotene, a potassic quaternary volcano in central Tyrrhenian Sea. Rend Soc It Min Petr (M. Carapezza Memorial Volume) 434: 1195–1213
Peccerillo A (1985) Roman comagmatic province (central Italy): evidence for subduction related magma genesis. Geology 13: 103–106
Pinarelli L (1991) Geochemical and isotopic (Sr, Pb) evidence of crust-mantle interaction in acidic melts - The Tolfa-Cerveteri-Manziana volcanic complex (central Italy): a case history. Chem Geol 92: 177–195
Poli G, Frey FA, Ferrara G (1984) Geochemical characteristics of the south Tuscany (Italy) Volcanic Province: constraints on lava petrogenesis. Chem Geol 43: 203–221
Rogers NW, Hawkesworth CJ, Parker RJ, Marsh JS (1985) The geochemistry of potassic lavas from M. Vulsini, central Italy and implications from mantle enrichment processes beneath the Roman region. Contrib Mineral Petrol 90: 244–257
Serri G (1990) Neogene-Quaternary magmatism of the Tyrrhenian region: characterization of the magma sources and geodynamic implications. Mem Soc Geol It 41: 219–242
Serri G, Innocenti F, Manetti P, Tonarini S, Ferrara G (1991) II magmatismo neogenicoquaternario dell'area tosco-laziale-umbra: implicatione sui modelli di evoluzione geodinamica dell'Appennino Settentrionale. Studi Geologici Camerti (Vol spec) 1991/1: 429–463
Taylor HP, Turi B (1976) High180 igneous rocks from the Tuscan magmatic province, Italy. Contrib Mineral Petrol 55: 33–54
Van Bergen MJ (1984) Magmas and inclusions of Monte Amiata, Tuscany, Italy. Geologica Ultraiectina 37: 175 pg
Vollmer R (1976) Rb-Sr and U-Th-Pb systematics of alkaline rocks: the alkaline rocks from Italy. Geochim Cosmochim Acta 40: 283–295
Vollmer R (1977) Isotopic evidence for genetic relations between acid and alkaline rocks in Italy. Contrib Mineral Petrol 60: 109–118
Wood D (1979) A variably veined suboceanic upper mantle-genetic significance for midocean ridge basalts from geochemical evidence. Geology 7: 499–503
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Bertagnini, A., De Rita, D. & Landi, P. Mafic inclusions in the silica-rich rocks of the Tolfa-Ceriti-Manziana volcanic district (Tuscan Province, Central Italy): Chemistry and mineralogy. Mineralogy and Petrology 54, 261–276 (1995). https://doi.org/10.1007/BF01162865
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DOI: https://doi.org/10.1007/BF01162865