Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-16T09:21:26.732Z Has data issue: false hasContentIssue false
  • English
  • Français

REE fractionation by accessory minerals in epidote-bearing metaluminous granitoids from the Sierras Pampeanas, Argentina

Published online by Cambridge University Press:  05 July 2018

J. A. Dahlquist
J. A. Dahlquist*
Affiliation:
Centro de Investigaciones Geológicas, CONICET-U.N.L.P., calle 1 N° 644, La Plata (1900), Argentina
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

A study of the distribution of REE in epidote-bearing metaluminous granitoids from Sierra de Chepes, Sierras Pampeanas, Argentina, reveals that a large proportion of the REE reside in the accessory minerals (allanite, epidote, titanite, apatite and zircon), and therefore these minerals control the behaviour of REE in granitic magmas. Well-developed chemical zonation in titanite indicates that the REE content decreases in the melt during crystallization of this mineral. The textural and chemical characteristics of euhedral epidote suggest a magmatic origin, and in that case it may have played an important role in the fractionation of the REE. The amount of silica and any other geochemical parameter indicative of fractionation progress in the dominant granodioritic-tonalitic facies (gtf) do not correlate with observed variations in the REE patterns. When many accessory minerals are involved, as in the gtf, the differentiated melts (e.g. aplites) are REE poor. Thus, the presence/absence of accessory minerals in granitoids can be indicative of the generation of differentiated melt enriched or poor in REE and other trace elements. This may have an economic significance, as it may allow us to predict the probable geochemistry of the differentiated melts (i.e. those that tend to develop mineralization) from the textural analysis of the ‘regional’ granitic rock.

Finally, the type and abundance of accessory minerals in the granitic suite can also help us to define the geotectonic environment where magmas were generated.

Keywords

accessory mineralsREEtrace elementsepidote-bearing granitoidsSierra de ChepesArgentina
Type
Research Article
Information
Mineralogical Magazine , Volume 65 , Issue 4 , August 2001 , pp. 463 - 475
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.)

Footnotes

†

Present address: Centro de Investigaciones Científicas y Transferencia Tecnolígica La Rioja, Dpto. de Geociencias, Petrología Ígnea y Geoquímica, Entre Ríos y Mendoza, Anillaco (5301), La Rioja, Argentina

References

Anderson, J.L. and Smith, D.R. (1995) The effects of temperature and f O2 on the Al-in hornblende barometer. Amer. Minera., 80, 549–59.CrossRefGoogle Scholar
Bea, F. (1996) Residence of REE, Y, Th and U in granites and crustal protoliths; implications for the chemistry of crustal melts. J. Petr., 37, 521–52.CrossRefGoogle Scholar
Blundy, J.D. and Holland, T.J.B. (1990) Calcic amphibole equilibria and a new amphibole-plagioclase geothermometer. Contrib. Mineral. Petrol., 104, 208–24.CrossRefGoogle Scholar
Dahlquist, J.A. (1999) Significado petrogenético del epidoto magmático en las granodioritas famatinianas de la Sierra de Chepes, Argentina. Bol. Soc. Espan∼ola Miner., 22a, 33–4.Google Scholar
Dahlquist, J.A. (2000) Geología, petrología y geoquímica de las rocas de la Sierra de Chepes, La Rioja, Argentina, . PhD thesis, Univ. Córdoba, Spain.Google Scholar
Dahlquist, J.A. and Baldo, G.E. (1996) Metamorfismo y deformación Famatinianos en la Sierra de Chepes, La Rioja, Argentina. XIII Congreso Geológico Argentino, V, 393–409. Buenos Aires, Argentina.Google Scholar
Dahlquist, J.A. and Rapela, C.W. (1997) Los granitoides Ordovícicos de la Sierra de Chepes, Batolito de Los Llanos-Ulapes, Sierras Pampeanas. XIV Reuniao de Geología do Oeste Peninsular. Comunicaçoes, 31–6. Vila Real, Portugal.Google Scholar
Dawes, R.L. and Evans, B.W. (1991) Mineralogy and geothermobarometry of magmatic epidote-bearing dikes, Front Range, Colorado. Geol. Soc. Amer. Bull., 103, 1017–31.2.3.CO;2>CrossRefGoogle Scholar
Exley, R.A. (1980) Microprobe studies of REE-rich accesory minerals: implications for Skye granite petrogenesis and REE mobility in hydrothermal systems. Earth Planet. Sci. Lett., 48, 97–110.CrossRefGoogle Scholar
Fourcade, S. and Allegre, C.J. (1981) Trace elements in granite genesis: a case study of the calc-alkaline plutonic associat ion from Querigut complex (Pyrénées, France). Contrib. Mineral. Petrol., 76, 177–95.CrossRefGoogle Scholar
Ghent, E.D., Nicholls, J., Simony, P.S., Sevigny, J.H. and Stout, M.Z. (1991) Hornblende geobarometry of the Nelson Batholith, southeastern British Columbia: tectonic implications. Canad. J. Earth Sci., 28, 1982–91.CrossRefGoogle Scholar
González del Tánago, J. (1997) Allanita- (Nd) y minerales de elementos raros en las pegmatitas graníticas de La Cabrera, Madrid (Sistema Ibérico Central). Rev. Soc. Geol. España., 10, 83–105.Google Scholar
Gromet, L.P. and Silver, L.T. (1983) Rare earth element distributions among minerals in a granodiorite and their petrogenetic implications. Geochim. Cosmochim. Act., 47, 925–39.CrossRefGoogle Scholar
Holland, T. and Blundy, J. (1994) Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry. Contrib. Mineral. Petrol., 116, 433–47.CrossRefGoogle Scholar
Jarosewich, E.J. and Boatner, L.A. (1991) Rare-earth element reference samples for electron microprobe analysis. Geostandards Newslette., 15, 397–9.CrossRefGoogle Scholar
Johnson, M.C. and Rutherford, M.J. (1989) Experimental calibration of the aluminium-in-hornblende geobarometer with application to Long Valley Caldera (California) volcanic rocks. Geology, 17, 837–41.2.3.CO;2>CrossRefGoogle Scholar
Keane, S.D. and Morrison, J. (1997) Distinguishing magmatic from subsolidus epidote: laser probe oxygen isotope compositions. Contrib. Mineral. Petrol., 126, 265–74.CrossRefGoogle Scholar
Kretz, R. (1983) Symbols for rock-forming minerals. Amer. Mineral., 68, 277–9.Google Scholar
Liu, X.C., Dong, S.W., Xue, H.M. and Zhou, J.X. (1999) Significance of allanite-(Ce) in granitic gneisses from the ultrahigh-pressure metamorphic terrane, Dabie Shan, central China. Mineral. Mag, 63, 579–86.CrossRefGoogle Scholar
Murra, J.A. and Baldo, E.G. (2000) Condiciones de cristalización del magmatismo Famatiniano en la Sierra de Las Minas-Ulapes Sierras Paas, Argentina: correlación con otros sectores. IX Congreso Geológico Chileno, I, 659–63.Google Scholar
Nakamura, N. (1974) Determination of REE, Ba, Fe, Mg, Na and K in carbonaceous and ordinary chondrites. Geochim. Cosmochim. Act., 38, 757–75.CrossRefGoogle Scholar
Pankhurst, R.J., Rapela, C.W., Saavedra, J., Baldo, E., Dahlquist, J.A., Pascua, I. and Fanning, C.M. (1998) The Famatinian arc in the central Sierras Pampeanas. Pp. 343–67 in: The Proto-Andean Margin of Gondwana, (Pankhurst, R.J. and Rapela, C.W., editors). Spec. Publ., 142. Geological Society, London.Google Scholar
Pankhurst, R.J., Rapela, C.W. and Fanning, C.M. (2001) Age and origin of coeval TTG, I- and S-type granites in the Famatinian belt of NW Argentina. Trans. Royal Soc. Edin. (in press).CrossRefGoogle Scholar
Rapela, C.W. (2000) Accretionary history and magma sources in the Southern Andes. 31st International Geological Congress., Río de Janeiro, Brazil. Abstract Volume.Google Scholar
Rapela, C.W., Pankhurst, R.J., Dahlquist, J.A. and Fanning, C.M. (1999) U-Pb SHRIMP ages of Famatinian granites: new constraints on the timing, origin and tectonic setting of I- and S-type magmas in an ensialic arc. II South American Symposium on Isotope Geology, Actas, 264–7.Google Scholar
Roeder, P.L. (1985) Electron-microprobe analysis of minerals for rare-earth elements: use of calculated peak-overlap corrections. Canad. Mineral., 23, 263–71.Google Scholar
Saavedra, J., Toselli, A.J., Rossi de Toselli, J.N. and Rapela, C.W. (1987) Role of tectonism and fractional crystallization in the origin of lower Paleozoic epidote-bearing granitoids, northwestern Argetnina. Geolog., 15, 709–13.2.0.CO;2>CrossRefGoogle Scholar
Sawka, W.N. (1988) REE and trace element variations in accesory minerals and hornblende from the strongly zone d McMury Meadows pluton, California. Trans. Royal Soc. Edinb.: Earth Sci., 79, 157–68.CrossRefGoogle Scholar
Sawka, W.N. and Chappell, B.W. (1988) Fractionation of uranium, thorium and rare earth elements in a granodiorite: implications for heat production distributions in the Sierra Nevada batholith, California U.S.A. Geochim. Cosmochim. Act., 52, 1131–43.CrossRefGoogle Scholar
Schmidt, M.W. (1992) Amphibole composition in tonalite as a function of pressure: An experimental calibration of the Al-in-hornblende barometer. Contrib. Mineral. Petrol., 110, 304–10.CrossRefGoogle Scholar
Schmidt, M.W. and Thompson, A.B. (1996) Epidote in calc-alkaline magmas: An experimental study of stability, phase relationships, and the role of epidote in magmatic evolution. Amer. Mineral., 81, 462–74.CrossRefGoogle Scholar
Sha, L.K. and Chappell, B.W. (1999) Apatite chemical composition determined by electron microprobe and laser-ablation inductively coupled plasma mass spectrometry, as a probe into granite petrogenesis. Geochim. Cosmochim. Act., 63, 3861–81.CrossRefGoogle Scholar
Sial, A.N., Toselli, A.J., Saavedra, J., Parada, M.A. and Ferreira, V.P. (1999) Emplacement, petrological and magmatic susceptibility characteristics of diverse magmatic epidote-bearing granitoid rocks in Brazil, Argentina and Chile. Litho., 46, 367–92.CrossRefGoogle Scholar
Thompson, R.N. (1982) British Tertiary volcanic province. Scot. J. Geol., 18, 49–107.CrossRefGoogle Scholar
Tulloch, A.J. (1979) Secondary Ca-Al silicates as lowgrade alteration products of granitoid biotite. Contrib. Mineral. Petrol., 69, 105–17.CrossRefGoogle Scholar
Tulloch, A.J. (1986) Comment on “Implications of magmatic epidote-bearing plutons on crustal evolution in the accreted terranes of north-western North America” and “Magmatic epidote and its petrologic significance”. Geolog., 14, 186–7.2.0.CO;2>CrossRefGoogle Scholar
Vhynal, C.R., McSween, H.Y. Jr. and Speer, J.A. (1991) Hornblende chemistry in southern Appalachian granitoids: implications for aluminum hornblende thermobarometry and magmatic epidote stability. Amer. Mineral., 76, 176–88.Google Scholar

A correction has been issued for this article:

Errata