Skip to main content
Log in

Crystal-chemistry of clinopyroxenes from potassic and ultrapotassic rocks in central Italy: implications on their genesis

  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

The clinopyroxenes mentioned have been investigated by single crystal X-ray diffraction combined with electron microprobe analysis. The aim of this study was to characterize the crystal-chemical variations of clinopyroxenes in order to delineate the intracrystalline constraints which are characteristic of specific magmatic environments. Clinopyroxenes (cpx) crystallized from peralkaline ultrapotassic melt with kamafugitic and lamproitic affinities are characterized by high Si contents, which are insensitive to variations in silica abundance and silica saturation of the melt. The high Si occupancy in clinopyroxenes from kamafugitic magma is coupled to large M1 (i.e. Mg and Fe2+) and M2 (high Ca occupancy) sites, whereas in clinopyroxenes from magmas with lamproitic affinity, high Si content is combined with large M1 but small M2 sites. Clinopyroxenes from Romantype alkaline potassic and ultrapostassic rocks are characterized by an expanded tetrahedron (high IVA1 content) and small M1 site which is combined with small M2 polyhedron in clinopyroxenes from the potassic rocks and large M2 site in those from the ultrapotassic rocks.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Appleton JD (1972) Petrogenesis of potassium rich lavas from Roccamonfina Volcano, Roman Region Italy. J Petrol 13:425–456

    Google Scholar 

  • Bruno E, Carbonin S, Molin G (1982) Crystal structure of Ca-rich clinopyroxenes on the CaMgSi2O6−Mg2Si2O6 join. Tschermaks Mineral Petrogr Mitt 29:223–240

    Google Scholar 

  • Burnham CW, Clark JR, Papike JJ, Prewitt CT (1967) A proposed crystallographic nomenclature for clinopyroxenes structure. Z Kristallogr 125:109–119

    Google Scholar 

  • Busing WR, Martin KO, Levy HS (1962) ORFLS, a fortran crystallographic least-squares program. USNTIS, ORNL-TM.305

  • Carbonin S, Dal Negro A, Molin GM, Munno R, Rossi G, Lirer L, Piccirillo EM (1984) Crystal chemistry of Ca-rich pyroxenes from undersatured to oversatured trachytic rocks, and their relationships with pyroxenes from basalts. Lithos 17:191–202

    Google Scholar 

  • Carbonin S, Salviulo G, Munno R, Desiderio M, Dal Negro A (1989) Crystal-chemiscal examination of natural diopsides: some geometrical indications of Si−Ti tetrahedral substitution. Mineral Petrol 41:1–10

    Google Scholar 

  • Carbonin S, Dal Negro S, Ganeo S, Piccirillo EM (1991) Influence of magma composition and oxygen fugacity on the crystal structure of C2/c clinopyroxenes from a basalt-pantellerite suite. Contrib Mineral Petrol 108:34–42

    Google Scholar 

  • Carmichael ISE (1967) The mineralogy and petrology of volcanics rocks from Leucite Hills Wyoming. Contrib Mineral Petrol 15:24–66

    Google Scholar 

  • Civetta L, Francalanci L, Manetti P, Peccerillo A (1987) Petrological and geochemical variations across the Roman Comagmatic Province: inference on magma genesis and crust-mantle evolution. In: Boriani A, Bonafede M, Piccardo GB, Vai GB (eds) The lithosphere in Italy, Accademia Nazionale Lincei Roma, pp 249–269

    Google Scholar 

  • Civetta L, Innocenti F, Manetti P, Peccerillo A, Poli G (1981) Geochemical characteristics of potassic volcanics from Mt. Ertnici (Southern Latium, Italy). Contrib Mineral Petrol 78:37–47

    Google Scholar 

  • Clark JR, Appleman DE, Papike JJ (1969) Crystal chemical characterization of clinopyroxenes based on eight new structure refinements. Mineral Soc Am Spec Pap 2:31–50

    Google Scholar 

  • Conticelli S (1989) Genesi del magmatismo alcalino-potassico dell'Italia centrale: evidenze petrologiche, geochimiche e petrologico sperimentali. PhD Thesis, Dept Earth Sci, Univ Firenze

  • Conticelli S, Peccerillo A (1990) Petrological significance of high pressure ultramafic xenoliths from ultrapotassic rocks of Central Italy. Lithos 24:305–322

    Google Scholar 

  • Conticelli S, Peccerillo A (1992) Petrology and geochemistry of potassic and ultrapotassic volcanism in central Italy: petrogenesis and inferences on the evolution of the mantle sources. Lithos 28:221–240

    Google Scholar 

  • Conticelli S, Cianci A, Francalanci L, Manetti P (1989) Studio geochimico e petrologico delle lave alcalino-potassiche del complesso vulcanico Sabatino (Italia Centrale): dati preliminari. Boll Gr Naz Vulcan 1989-2:745–761

    Google Scholar 

  • Conticelli S, Francalanci L, Santo AP (1991) Petrology of final stage Latera lavas, Vulsini Mts.: mineralogical, geochimical and Sr isotopic data on their bearing on the genesis of some potassic magmas in Central Italy. J Volcanol Geothermal Res 46:186–212

    Google Scholar 

  • Conticelli S, Manetti P, Menichetti S (1992) Petrology, chemistry, mineralogy and Sr-isotopic data of Pliocenic Orendites from South Tuscany. Eur J Mineral 4:1359–1375

    Google Scholar 

  • Cundari A, Salviulo G (1989) Ti solubility in diopsidic pyroxene from a suite of new South Wales leucitites (Australia). Lithos 22:191–198

    Google Scholar 

  • Dal Negro A, Carbonin S, Molin GM, Cundari A, Piccirillo EM (1982) Intracrystalline cation distribution in natural clinopyroxenes of tholeiitic transitional and alkaline basaltic rocks. In: Saxena SK (ed) Advances in physical geochemistry, Vol 2. Springer, Berlin Heilderberg New York, pp.117–150

    Google Scholar 

  • Dal Negro A, Carbonin S, Salviulo G, Piccirillo EM, Cundari A (1985) Crystal chemistry and site configuration of the clinopyroxene from leucite-bearing rocks and related genetic significance: the Sabatini lavas, Roman Region, Italy. J Petrol 26:1027–1040

    Google Scholar 

  • Dal Negro A, Cundari A, Piccirillo EM, Molin GM, Uliana D (1986) Distintive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks: the Nyambeni clinopyroxene suite, Kenya. Contrib Mineral Petrol 92:35–43

    Google Scholar 

  • Dal Negro A, Molin GM, Secco L, Cundari A, Piccirillo EM (1989) Crystal-chemistry of clinopyroxene and its genetic significance: a new approach. In: Boriani A, Bonafede M, Piccardo GB, Vai GB (eds) The lithosphere in Italy: advances in Earth sciences research. Atti dei Convegni Lincei 80, pp 271–295

  • Freed RL, Peacor DR (1967) Refinement of the crystal structure of johannsenite. Am Mineral 52:709–720

    Google Scholar 

  • Hamilton WC (1959) On the isotropic temperature factor equivalent to a given anisotropic temperature factor. Acta Crystallogr 12:609–610

    Google Scholar 

  • Hamilton WC (1965) Significance tests on the crystallographic R factors. Acta Crystallogr 18:502–510

    Google Scholar 

  • Jaques AL, Lewis GD, Smith CB, Gregory CP, Ferguson J, Chappell BW, McCulloch MT (1984) The diamond-bearing ultrapotassic (lamproitic) rocks of West-Kimberly region, Western Australia. In: Kornprobst J (ed) Kimberlites and related rocks. Proc 3rd Int Kimberlite Conf, vol 1, Elsevier, Amsterdam, pp 223–254

    Google Scholar 

  • Malgarotto C, Molin G, Zanazzi PF (1993a) Cooling history of a dyke on Alicudi (Aeolian Islands) from intracrystalline Fe2+−Mg exchange reaction in clinopyroxene. Eur J Mineral 5:755–762

    Google Scholar 

  • Malgarotto C, Molin G, Zanazzi PF (1993b) Crystal-chemistry of clinopyroxenes from Filicudi and Salina (Aeolian Islands, Italy). Geothermometry and barometry. Eur J Mineral 5:915–923

    Google Scholar 

  • Mitchell RH (1985) A review of the mineralogy of lamproites. Trans Geol Soc S Afr 88:411–437

    Google Scholar 

  • Morimoto N, (1989) Nomenclature of pyroxenes. Can Mineral 27:143–156

    Google Scholar 

  • North aCT, Phillips DC, Mathews FS (1968) A semi-empirical method of absorbation correction. Acta Crystallogr A24:351–359

    Google Scholar 

  • Peccerillo A, Manetti (1985) The potassium alkaline volcanism of central Southern Italy: a review of the data relevant to petrogenesis and geodynamic significance. Trans Geol Soc S Afr 88:379–394

    Google Scholar 

  • Peccerillo A, Poli G, Tolomeo L (1984) Genesis, evolution and tectonic significance of K-rich volcanics from the Alban Hills (Roman Comagmatic Region) as inferred from trace element geochemistry. Contrib Mineral Petrol 86:230–240

    Google Scholar 

  • Peccerillo A, Conticelli S, Manetti P (1987) Petrological characteristics and the genesis of the recent magmatism of South Tuscany and North Latium. Period Mineral 56:167–183

    Google Scholar 

  • Peccerillo A, Poli G, Serri G (1988) Petrogenesis of orenditic and kamafugitic rocks from Central Italy. Can Mineral 26:45–65

    Google Scholar 

  • Robinson K, Gibbs GV, Ribbe PH (1971) Quadratic elongation; a quantitative measure of distortion in coordination polyhedra. Science 172:567–570

    Google Scholar 

  • Rossi G, Tazzoli V, Ungaretti L (1978) Crystal-chemical studies on sodic clinopyroxenes (abstract). XIth Gen Meet IMA Abstr 1:29

    Google Scholar 

  • Rossi G, Smith DC, Ungaretti L, Domeneghetti MC (1983) Crystalchemistry and cation ordering in the system diopside-jadeite: a detailed study by crystal structure refinement. Contrib Mineral Petrol 83:247–258

    Google Scholar 

  • Rossi G, Oberti R, Dal Negro A, Molin GM, Mellini M (1987) Residual electron density at the M2 site in C2/c clinopyroxenes: relationships with bulk chemistry and sub-solidus evolution. Phys Chem Miner 14:514–520

    Google Scholar 

  • Sasaki S, Takeuchi Y, Fuyino K, Akimoto S (1982) Electron-density distributions of three orthopyroxenes, Mg2Si2O6, Co2Si2O6 and Fe2Si2O6. Z Kristallogr 158:279–297

    Google Scholar 

  • Ungaretti L, Smith DC, Rossi G (1981) Crystal-chemistry by X-ray structure refinement and electron microprobe analysis of a series of sodic-calcic to alkali-amphiboles from the Nybö eclogite pod, Norway. Bull Mineral 104:400–412

    Google Scholar 

  • Virgo D (1972) 57Fe Mossbauer analyses of Fe3+ clinopyroxenes. Carnegie Inst Washington Yearb 71:534–538

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Cellai, D., Conticelli, S. & Menchetti, S. Crystal-chemistry of clinopyroxenes from potassic and ultrapotassic rocks in central Italy: implications on their genesis. Contr. Mineral. and Petrol. 116, 301–315 (1994). https://doi.org/10.1007/BF00306499

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00306499

Keywords

Navigation