Abstract
A series of monazite dissolution experiments was conducted in a hydrous (1–6 wt.%) granitic melt at 8 kbar over the temperature range 1,000–1,400° C. A polished cube of monazite was immersed in a natural obsidian melt and allowed to partially dissolve. Electron microprobe traverses perpendicular to the crystal-melt interface revealed concentration gradients in the LREEs and P. Diffusivities of the LREEs and P were calculated from these profiles, yielding the following Arrhenius relations for the LREEs: D=0.23 exp(−60.1 kcal mol−1/RT) at 6% water D=2.30×107 exp(−122.1 kcal mol−1/RT) at 1% water These results demonstrate the importance of dissolved water on REE diffusion. Phosphorus diffusivities are nearly identical to those of the rare-earths, suggesting that P diffusion charge-compensates REE diffusion. The concentration of LREEs required for monazite saturation in these melts is given by the level of dissolved LREEs at the crystal-melt interface. These values also show a dependence on dissolved water, with LREEsat=60 ppm at 6% H2O when extrapolated down to 700° C, and LREEsat=30 ppm at 1% H2O. Calculated dissolution rates based on the above parameters indicate that minute (<30 μm diameter) monazite crystals will be readily digested by an enclosing anatectic magma under reasonable geologic conditions (i.e., T=700–800° C and >2% H2O), whereas larger (> 50 μm) crystals will likely be residual over the duration of an anatectic event. The low solubility of monazite in this melt suggests that the LREE depletion observed in some felsic differentiation suites may be the result of monazite crystallization. Limited experimental and geochemical/petrologic evidence indicates that compositional changes in the melt accompanying differentiation decrease the solubility of monazite drastically. Kinetic and chemical constraints may also lead to localized monazite saturation and inclusion in major phases or even other accessories. Variations in the REE composition of monazite from different parageneses probably reflects the REE pattern of the parent melt, and may be due to gradational differences in the stability of individual or subgroup REE-complexes as a function of melt composition. Particularly important in this regard seems to be the lime+alkali/alumina balance of the melt and its volatile content.
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References
Acocella J, Tomozawa M, Watson EB (1984) The nature of dissolved water in sodium silicate melts and its effect on various properties. J Non-Cryst Solids 65:355–372
Amli R (1975) Mineralogy and rare-earth geochemistry of apatite and xenotime from the Gloserheia granite pegmatite, Froland, southern Norway. Am Mineral 60:607–620
Arth JG (1976) Behavior of trace elements during magmatic processes-a summary of theoretical models and their applications. J Res US Geol Surv 4:41–47
Baranov VI, Lieh-T'ien D (1961) Geochemistry of uranium and thorium in the granites of the Kyzyltan Massif. Geochemistry 12:1180–1191
Bence AE, Albee AL (1968) Empirical correction factors for the electron microanalysis of silicates and oxides. J Geol 76:382–403
Condie KC (1978) Geochemistry of Proterozoic granitic plutons from New Mexico, USA. Chem Geol 21:131–149
Crank J (1975) The Mathematics of Diffusion. 2nd ed, Oxford University Press
Carslaw HS, Jaeger JC (1959) Conduction of heat in solids. Oxford University Press, Oxford, p 510
Deer WA, Howie RA, Zussman J (1966) An introduction to the rock-forming minerals: nonsilicates. Longham Group, London
Drake MJ, Weill DF (1972) New rare-earth element standards for electron microprobe analysis. Chem Geol 10:179–181
Dunn JT (1982) Oxygen diffusion in three silicate melts along the join diopside-anorthite. Geochim Cosmochim Acta 46:2293–2299
Emmermann R, Daieva L, Schneider J (1975) Petrologic significance of rare-earths distribution in granites. Contrib Mineral Petrol 52:267–283
Eyring H (1935) The activated complex and the absolute rate of chemical reactions. Chem Rev 17:65–82
Fleischer MW (1965) Some aspects of the geochemistry of yttrium and the lanthanides. Geochim Cosmochim Acta 29:755–772
Fleischer MW, Altschuler ZS (1969) The relationship of the rare earth composition of minerals to geologic environment. Geochim Cosmochim Acta 33:725–732
Fourcade S, Allegre CJ (1981) Trace element behavior in granite genesis: a case study-the calc-alkaline plutonic association from the Querigut complex (Pyrenees, France). Contrib Mineral Petrol 76:177–195
Gast PW (1968) Trace element fractionation and the origin of tholeiite and alkaline magma types. Geochim Cosmochim Acta 32:1057–1086
Gavrilova LK, Turanskaya RV (1958) Distribution of rare-earths in rock-forming and accessory minerals of certain granites. Geochemistry 2:163–169
Goldschmidt VM, Thomassen L (1924) Geochemische Verteilungs-gesetze der elemente III. Roentgenspektrographische Untersuchungen über die Verteilung der seltenen Erdmetalle in Mineralen. Skr, Norske Vidensk Akad Mat Naturw Klasse No. 5:1–50
Green TH, Watson EB (1982) Crystallization of apatite in natural magmas under high pressure hydrous conditions, with particular reference to orogenic rock series. Contrib Mineral Petrol 79:96–105
Gromet LP, Silver LT (1983) Rare-earth element distributions among minerals in a granodiorite and their petrogenetic implications. Geochim Cosmochim Acta 47:925–939
Hanson GN (1978) The application of trace elements to the petrogenesis of igneous rocks of granitic compositon. Earth Planet Sci Lett 38:26–43
Harrison TM, Watson EB (1983) Kinetics of zircon dissolution and zirconium diffusion in granitic melts of variable water content. Contrib Mineral Petrol 84:66–72
Harrison TM, Watson EB (1984) The behavior of apatite during crustal anatexis: equilibrium and kinetic considerations. Geochim Cosmochim Acta 48:1467–1477
Heinrich EW, Borup RA, Levinson AA (1960) Relationship between geology and composition of some pegmatitic monazites. Geochim Cosmochim Acta 19:222–231
Heinrich KFJ (1978) Electron Beam X-ray Microanalysis. Van Nostrand Reinhold, New York
Henderson P, Nolan J, Cunningham GC, Lowry RK (1985) Structural controls and mechanisms of diffusion in natural silicate melts. Contrib Mineral Petrol 89:263–272
Hofmann AW (1980) Diffusion in natural silicate melts: a critical review. In: Hargraves RB (ed) Physics of Magmatic Processes. Princeton Univ Press, Princeton, NJ pp 385–417
Jambon A (1982) Tracer diffusion in granitic melts: experimental results for Na, K, Rb, Cs, Ca, Sr, Ba, Ce, and Eu to 1300 C and a model of calculation. J Geophys Res 87:10797–10810
Jensen BB (1966) Distribution patterns of rare-earth elements in cerium rich minerals. Norsk Geologisk Tidsskrift 47:9–19
Lasaga AC (1981) Transition state theory. in: Kinetics of Geochemical Processes. Rev Mineral Vol 8, Mineral Soc Am
Lee DE, Dodge FCW (1964) Accessory minerals in some granitic rocks in California and Nevada as a function of calcium content. Am Mineral 49:1660–1669
Lee DE, Bastron H (1967) Fractionation of rare-earth elements in allanite and monazite as related to geology of the Mt. Wheeler mine area, Nevada. Geochim Cosmochim Acta 31:339–356
Lyakhovich VV (1962) Rare-earth elements in the accessory minerals of granitoids. Geochemistry 1:39–55
Lyakhovich VV (1967) Distribution of rare-earths among the accessory minerals of granites. Geochemistry 7:691–696
Lyakhovich VV, Barinskii RL (1961) Characteristics of the rare earth assemblages in the accessory minerals of granitoids. Geochemistry 6:495–509
McAdams RE (1936) The accessory minerals of the Wolf Mountain granite, llano County, Texas. Am Mineral 21:128–135
Mackie W (1928) The heavier accessory minerals in the granites of Scotland. Edinburgh Geol Soc Trans 12:22–40
McCarthy TS, Kable EJD (1978) On the behavior of rare-earth elements during partial melting of granitic rocks. Chem Geol 22:21–29
Miller CF, Mittlefehldt DW (1982) Depletion of light rareearth elements in felsic magmas. Geology 10:129–133
Mineyev DA (1960) Certain geochemical peculiarities of the radio-active rare-earth minerals. Geochemistry 2:156–166
Mineyev DA (1963) Geochemical differentiation of the rare-earths. Geochemistry 12:1129–1149
Mittlefehldt DW, Miller CF (1983) Geochemistry of the Sweetwater Wash Pluton, California: implications for “anomalous” trace element behavior during differentiation of felsic magmas. Geochim Cosmochim Acta 47:109–124
Murata KJ, Rose HJ Jr, Carron MK (1953) Systematic variation of rare-earths in monazite. Geochim Cosmochim Acta 4:292–300
Murata KJ, Rose HJ Jr, Carron MK, Glass JJ (1957) Systematic variation of rare-earth elements in cerium-earth minerals. Geochim Cosmochim Acta 11:141–161
Murata KJ, Dutra CV, Teixeira da Costa M, Branco JR (1958) Composition of monazites from pegmatites in eastern Minas Gerais, Brazil. Geochim Cosmochim Acta 16:1–14
Nelson C, White WB (1980) Transition metal ions in silicate melts-I. manganese in sodium silicate melts. Geochim Cosmochim Acta 44:887–893
Nelson C, Furukawa T, White WB (1983) Transition metal ions in glasses: network modifiers or quasimolecular complexes?. Mat Res Bull 18:959–966
Overstreet WC (1967) The geologic occurrence of monazite. US geol Surv Prof Paper No 530:327
Pagel M (1982) The mineralogy and geochemistry of uranium, thorium and rareearth elements in two radioactive granites of the Vosges, France. Mineral Mag 46:149–161
Petersen JS (1980) Rare-earth element fractionation and petrogenetic modelling in charnockitic rocks, Southwest Norway. Contrib Mineral Petrol 73:161–172
Pigorini B, Veniale F (1968) L'apatite accessoria nella diverse facies litologiche delle formationi granitoidi della Val Sersera (Vercelli) Rendiconti Soc Ital Mineral Petrol 24:32
Pidgeon RT, Aftalion M (1978) Cogenetic and inherited zircon U-Pb systems in granites; Paleozoic granites of Scotland and England. In: (Bowes DR et al. (ed), Crustal evolution in north-western Britain and adjacent regions. Geol J (Liverpool), [Spec Issue] 10:183–220
Pavlenko AS, Vainshtein EE, Turanskaya NV (1958) Certain regularities in the behavior of rare earths and yttrium in magmatic and post-magmatic processes. Geochemistry 4:357–380
Rapp RP, Ryerson FJ, Miller CF (1986) Monazite and allanite in the crust: implications to the distribution of the LREEs, Y, U and Th. EOS 67, No 16 p 386
Ryerson FJ, Hess PC (1978) Implications of liquid-liquid distribution coefficients to mineral-liquid partitioning. Geochim Cosmochim Acta 42:921–932
Sahama TG, Vahatalo V (1941) X-ray spectrographic study of the rare-earths in some Finnish eruptive rocks and minerals. Bull Comm Geol Finland 126:50–83
Sawka WN, Chappell BW (1985) The distribution of radioactive heat in I-and S-type granites residual source regions: implications to high heat flow areas in the Lachlan fold belt, Australia. Aust J Earth Sci (in press)
Sawka WN, Chappell BW, Norrish K (1984) Light rare-earth element zoning in sphene and allanite during granitoid fractionation. Geology 12:131–134
Semenov EI (1958) Relationship between composition of rare-earths and compostion and structure of minerals. Geochemistry 2:163–169
Semenov EI, Barinskii RL (1958) The composition characteristics of the rare-earths in minerals. Geochemistry No. 4:398–419
Shaw DM (1970) Trace element behavior during anatexis. Geochim Cosmochim Acta 34:237–243
Smith VG, Tiller WA, Rutter JW (1955) A mathematical analysis of solute redistribution during solidification. Can J Physics 33:723–744
Stolper E (1982) Water in silicate glasses: An infrared spectroscopic study. Contrib Mineral Petrol 81:1–17
Sun SS, Hanson GN (1975) Origin of Ross Island basanitoids and limitations on the heterogeneity of mantle sources for alkali basalts and nephelinites. Contrib Mineral Petrol 52:77–106
Schilling JG, Winchester JW (1967) Rare-earth fractionation and magmatic processes. In: Runcorn SK (ed) Mantles of the Earth and terrestrial planets Intersci Publ, p 267–283
Vainshtein EE, Tugarinov Ai, Turanskaya NV (1955) The distribution of rare-earths in monazite. Dokl Akad Nauk SSSR 104:268–271
Vainshtein EE, Tugarinov AI, Turanskaya NV (1956a) Distribution of the rare-earths in monazites of granitoids. Dokl Akad Nauk SSR 106:691–692
Vainshtein EE, Tugarinov AI, Turanskaya NV. (1956b) Regularities in the distribution of rareearths in certain minerals. Geochemistry 6:159–178
Vernadskii VI (1924) Dokl Akad Nauk SSR, Ser I, p 35
Watson EB (1979) Zircon saturation in felsic liquids: Experimental data and applications to trace element geochemistry. Contrib Mineral Petrol 70:407–419
Watson EB (1980) Some experimentally-determined zircon/liquid partition coefficients for the rare-earth elements. Geochim Cosmochim Acta 44:895–897
Watson EB (1986) Chemical diffusion in magmas: an overview of experimental results and geochemical applications. In: I. Kushiro and L. Perchuk (eds) Advances in Physical Geomistry vol. 3 Springer, Berlin Heidelberg New York Tokyo (in press)
Watson EB, Capobianco CJ (1981) Phosphorus and the rare-earth elements in felsic magmas: an assessment of the role of apatite. Geochem Cosmochim Acta 45:2349–2358
Watson EB, Harrison TM (1983) Zircon saturation revisited: Temperature and composition effects in a variety of crustal magma types. Earth Planet Sci Lett 64:295–304
Watson EB, Harrison TM (1984) Accessory minerals and the geochemical evolution of crustal magmatic systems: a summary and prospectus of experimental approaches. Phys Earth Planet Int 35:19–30
Weber C, Barbery P, Cuney M, Martin H (1985) Trace element behavior during migmatization: evidence for a complex meltresiduum-fluid interaction in the St. Malo migmatitic dome (France) Contrib Mineral Petrol 90:52–62
Whittaker EJW, Muntus R (1970) Ionic radii for use in geochemistry. Geochim Cosmochim Acta 34:945–956
Williams IS, Compston W, Chappell BW (1983) Zircon and monazite U-Pb systems and the histories of I-type magmas, Berridale Batholith, Australia. J Petrol 24:76–97
Yeliseyeva OP (1977) Content and distribution of uranium, thorium, yttrium and the rare-earths in accessory minerals in granitoids. Geochemsitry 9:37–49
Yeskova Ye M, Ganseyev AA (1964) Rare-earth elements in accessory minerals of the Vishnev Mountains. Geochemistry 12:1152–1163
York D (1966) Least-squares fitting of a straight line. Can J Phys 44:1079–1086
Yost DM, Russell H Jr, Garner CS (1947) The rare-earths and their compounds. Wiley, New York, Inc p 42
Zayats AP, Kuts VP (1964) Rare-earth elements in the accessory minerals of gneisses of the Ukrainian crystalline shield. Geochemistry 11:1209–1210
Zhirov KK, Bandurkin GA, Lavrentýev YG (1961) Geochemistry of rare-earth elements in pegmatites of northern Karelia. Geochemistry 11:1107–1118
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Rapp, R.P., Watson, E.B. Monazite solubility and dissolution kinetics: implications for the thorium and light rare earth chemistry of felsic magmas. Contr. Mineral. and Petrol. 94, 304–316 (1986). https://doi.org/10.1007/BF00371439
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DOI: https://doi.org/10.1007/BF00371439