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Experimental delineation of the “e” ⇌ I\(\bar 1\) and “e” ⇌ C\(\bar 1\) transformations in intermediate plagioclase feldspars

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Abstract

Approximately 125 hydrothermal annealing experiments have been carried out in an attempt to bracket the stability fields of different ordered structures within the plagioclase feldspar solid solution. Natural crystals were used for the experiments and were subjected to temperatures of ∼650°C to ∼1,000°C for times of up to 370 days at \(P_{{\text{H}}_{\text{2}} {\text{O}}} \)=600 bars, or \(P_{{\text{H}}_{\text{2}} {\text{O}}} \)=1,200 bars. The structural states of both parent and product materials were characterised by electron diffraction, with special attention being paid to the nature of type e and type b reflections (at h+k=(2n+1), l=(2n+1) positions).

Structural changes of the type C \(\bar 1\) → I \(\bar 1\), C \(\bar 1\) → “e” structure, I \(\bar 1\) → “e” and “e” structure → I \(\bar 1\) have been followed. There are marked differences between the ordering behaviour of crystals with compositions on either side of the C \(\bar 1\) ⇌ I \(\bar 1\) transition line. In the composition range ∼ An50 to ∼ An70 the e structure appears to have a true field of stability relative to I \(\bar 1\) ordering, and a transformation of the type I \(\bar 1\) ⇌ e has been reversed. It is suggested that the e structure is the more stable ordered state at temperatures of ∼ 800°C and below. For compositions more albite-rich than ∼ An50 the upper temperature limit for long range e ordering is lower than ∼ 750°C, and there is no evidence for any I \(\bar 1\) ordering.

The evidence for a true stability field for “e” plagioclase, which is also consistent with calorimetric data, necessitates reanalysis both of the ordering behaviour of plagioclase crystals in nature and of the equilibrium phase diagram for the albite-anorthite system. Igneous crystals with compositions of ∼ An65, for example, probably follow a sequence of structural states C \(\bar 1\) → I \(\bar 1\) → e during cooling. The peristerite, Bøggild and Huttenlocher miscibility gaps are clearly associated with breaks in the albite, e and I \(\bar 1\) ordering behaviour but their exact topologies will depend on the thermodynamic character of the order/disorder transformations.

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References

  • Bambauer HU, Bernotat WH (1982) The microcline/sanidine transformation isograd in metamorphic regions. I. Composition and structural state of alkali feldspars from granitoid rocks of two N-S traverses across the Aar Massif and Gotthard “Massif”, Swiss Alps. Schweiz Mineral Petrogr Mitt 62:185–230

    Google Scholar 

  • Bambauer HU, Eberhard E, Viswanathan K (1967a) The lattice constants and related parameters of “plagioclases (low)”. Schweiz Mineral Petrogr Mitt 47:351–364

    Google Scholar 

  • Bambauer HU, Corlett M, Eberhard E, Viswanathan K (1967b) Diagrams for the determination of plagioclases using X-ray powder methods. Schweiz Mineral Petrogr Mitt 47:333–349

    Google Scholar 

  • Bernard L, Currat R, Delamoye P, Zeyen CME, Hubert S, de Kouchovsky R (1983) Neutron scattering investigation of incommensurate ThBr4. J Phys C Solid State Phys 16:433–456

    Google Scholar 

  • Bernotat WH, Bambauer HU (1982) The microcline/sanidine transformation isograd in metamorphic regions. II. The region of Lepontine metamorphism, Central Swiss Alps. Schweiz Mineral Petrogr Mitt 62:231–244

    Google Scholar 

  • Blencoe JG, Merkel GA, Seil MK (1982) Thermodynamics of crystal-fluid equilibria, with applications to the system NaAlSi3O8-CaAl 2Si2O8-SiO2-NaCl-CaCl 2-H2O. In: Saxena SK (ed) Advances in physical geochemistry, Vol. 2, Springer-Verlag, Berlin Heidelberg New York, pp 191–222

    Google Scholar 

  • Böhm H (1983) Modulated structures at phase transitions. Am Mineral 68:11–17

    Google Scholar 

  • Bown MG, Gay P (1958) The reciprocal lattice geometry of the plagioclase felspar structures. Z Kristallogr 111:1–14

    Google Scholar 

  • Bruce AD, Cowley RA, Murray AF (1978) The theory of structurally incommensurate systems: II. Commensurate-incommensurate phase transitions. J Phys C Solid State Phys 11:3591–3608

    Google Scholar 

  • Cameron WE (1977) Mullite: a substituted alumina. Am Mineral 62:747–755

    Google Scholar 

  • Carpenter MA (1981a) Time-temperature-transformation (TTT) analysis of cation disordering in omphacite. Contrib Mineral Petrol 78:433–440

    Google Scholar 

  • Carpenter MA (1981b) A “conditional spinodal” within the peristerite miscibility gap of plagioclase feldspars. Am Mineral 66:533–560

    Google Scholar 

  • Carpenter MA (1985) Order-disorder transformations in mineral solid solutions. In: Kieffer SW, Navrotsky A (eds) Reviews in Mineralogy, Vol. 14, Microscopic to Macroscopic: Atomic Environments to Mineral Thermodynamics. Mineralogical Society of America, pp 187–223

  • Carpenter MA, Ferry JM (1984) Constraints on the thermodynamic mixing properties of plagioclase feldspars. Contrib Mineral Petrol 87:138–148

    Google Scholar 

  • Carpenter MA, McConnell JDC (1984) Experimental delineation of the C \(\bar 1\) ⇌ I \(\bar 1\) transformation in intermediate plagioclase feldspars. Am Mineral 69:112–121

    Google Scholar 

  • Carpenter MA, McConnell JDC, Navrotsky A (1985) Enthalpies of ordering in the plagioclase feldspar solid solution. Geochim Cosmochim Acta 49:947–966

    Google Scholar 

  • Christoffersen RG, Yund RA (1984) An experimental study of the Al,Si distribution in the average structure of andesine. Neues Jahrb Mineral Abh 149:91–104

    Google Scholar 

  • Cowley RA, Bruce AD (1978) The theory of structurally incommensurate systems: I. Disordered-incommensurate phase transitions. J Phys C Solid State Phys 11:3577–3590

    Google Scholar 

  • Dolino G, Bachheimer JP, Berge B, Zeyen CME (1984) Incommensurate phase of quartz: I. Elastic neutron scattering. J Physique 45:361–371

    Google Scholar 

  • Dolino G, Bachheimer JP, Berge B, Zeyen CME, Van Tendeloo G, Van Landuyt J, Amelinckx S (1984) Incommensurate phase of quartz: III. Study of the coexistence state between the incommensurate and the α-phases by neutron scattering and electron microscopy. J Physique 45:901–912

    Google Scholar 

  • Doman RC, Cinnamon CG, Bailey SW (1965) Structural discontinuities in the plagioclase feldspar series. Am Mineral 50:724–740

    Google Scholar 

  • Durand D (1982) Statique et dynamique de la phase incommensurable du nitrite de sodium. Thesis, l'Université de Paris-Sud, Centre d'Orsay

  • Fleet ME (1981) The intermediate plagioclase structure: an explanation from interface theory. Phys Chem Minerals 7:64–70

    Google Scholar 

  • Fleet ME (1984) Orientation of feldspar intergrowths: Application of lattice misfit theory to cryptoperthites and e-plagioclase. Bull Minéral 107:509–519

    Google Scholar 

  • Gay P (1954) The structures of the plagioclase felspars: V. The heat-treatment of lime-rich plagioclases. Mineral Mag 30:428–438

    Google Scholar 

  • Gay P (1956) The structures of the plagioclase felspars: VI. Natural intermediate plagioclases. Mineral Mag 31:21–40

    Google Scholar 

  • Gay P, Bown MG (1956) The structures of the plagioclase felspars: VII. The heat treatment of intermediate plagioclases. Mineral Mag 31:306–313

    Google Scholar 

  • Gay P, Muir ID (1962) Investigation of the feldspars of the Skaergaard intrusion, Eastern Greenland. J Geol 70:565–581

    Google Scholar 

  • Grove TL (1977) Structural characterization of labradorite-bytownite plagioclase from volcanic, plutonic and metamorphic environments. Contrib Mineral Petrol 64:273–302

    Google Scholar 

  • Grove TL, Baker MB, Kinzler RJ (1984) Coupled CaAl-NaSi diffusion in plagioclase feldspar: experiments and applications to cooling rate speedometry. Geochim Cosmochim Acta 48:2113–2121

    Google Scholar 

  • Grove TL, Ferry JM, Spear FS (1983) Phase transitions and decomposition relations in calcic plagioclase. Am Mineral 68:41–59

    Google Scholar 

  • Hashimoto H, Nissen H-U, Ono A, Kumao A, Endoh E, Woensdregt CF (1976) High resolution electron microscopy of labradorite feldspar. In: Wenk H-R (ed) Electron Microscopy in Mineralogy. Springer-Verlag, Berlin Heidelberg New York, pp 332–344

    Google Scholar 

  • Heine V, McConnell JDC (1981) Origin of modulated incommensurate phases in insulators. Phys Rev Letters 46:1092–1095

    Google Scholar 

  • Heine V, McConnell JDC (1984) The origin of incommensurate structures in insulators. J Phys C Solid State Phys 17:1199–1220

    Google Scholar 

  • Heine V, Price SL (1985) The origin of the incommensurate phase III of biphenyl. J Phys C Solid State Phys 18:5259–5278

    Google Scholar 

  • Hofmeister AM, Rossman GR (1984) Determination of Fe3+ and Fe2+ concentrations in feldspar by optical absorption and EPR spectroscopy. Phys Chem Minerals 11:213–224

    Google Scholar 

  • Horst W (1984) Modulated structures in intermediate plagioclases — history, ideas and perspectives. Fortschr Mineral 62:107–154

    Google Scholar 

  • Iizumi M, Gesi K (1977) Incommensurate phase in (ND4)2BeF4. Solid State Commun 22:37–39

    Google Scholar 

  • Ishibashi Y, Dvorak V (1978) Incommensurate phase transitions under the existence of the Lifshitz invariant. J Phys Soc Jap 44:32–39

    Google Scholar 

  • Kitamura M, Morimoto N (1984) The modulated structure of the intermediate plagioclases and its change with composition. In: Brown WL (ed) NATO ASI Series C, Vol. 137, Feldspars and Feldspathoids. Reidel, Dordrecht Boston Lancaster, pp 95–119

    Google Scholar 

  • Kotel'nikov AR, Bychkov AM, Chenavina NI (1981) The distribution of calcium between plagioclase and water-salt fluid at 700° C and Pf1=1,000 kg/cm2. Geochem Internat 18:61–75

    Google Scholar 

  • Kroll H, Müller WF (1980) X-ray and electron-optical investigation of synthetic high-temperature plagioclases. Phys Chem Minerals 5:255–277

    Google Scholar 

  • MacKenzie WS (1957) The crystalline modifications of NaAl/Si3O8. Am J Sci 255:481–516

    Google Scholar 

  • McConnell JDC (1974) Analysis of the time-temperature-transformation behaviour of the plagioclase feldspars. In: MacKenzie WS, Zussman J (eds) The Feldspars. Manchester University Press, pp 460–477

  • McConnell JDC (1978) The intermediate plagioclase feldspars: an example of a structural resonance. Z Kristallogr 147:45–62

    Google Scholar 

  • McConnell JDC (1981) Electron-optical study of modulated mineral solid solutions. Bull Minéral 104:231–235

    Google Scholar 

  • McConnell JDC (1983) A review of structural resonance and the nature of long-range interactions in modulated structures. Am Mineral 68:1–10

    Google Scholar 

  • McConnell JDC, Heine V (1985) Incommensurate structure and stability of mullite. Phys Rev B 31:6140–6142

    Google Scholar 

  • McConnell JDC, McKie D (1960) The kinetics of the ordering process in triclinic NaA/Si3O8. Mineral Mag 32:436–454

    Google Scholar 

  • McLaren AC, Marshall DB (1974) Transmission electron microscope study of the domain structures associated with b-, c-, d-, e- and f-reflections in plagioclase feldspars. Contrib Mineral Petrol 44:237–249

    Google Scholar 

  • McMillan WL (1976) Theory of discommensurations and the commensurate-incommensurate charge-density-wave phase transition. Phys Rev B 15:1496–1502

    Google Scholar 

  • Megaw HD (1962) Order and disorder in feldspars. Norsk Geol Tidsskr 42:2:104–137

    Google Scholar 

  • Morimoto N (1979) The modulated structure of feldspars. In: Cowley JM, Cohen JB, Salamon MB, Wuensch BJ (eds) Modulated Structures. American Institute of Physics, New York, pp 299–310

    Google Scholar 

  • Newton RC, Charlu TV, Kleppa OJ (1980) Thermochemistry of the high structural state plagioclases. Geochim Cosmochim Acta 44:933–941

    Google Scholar 

  • Nord GL Jr., Heuer AH, Lally JS (1974) Transmission electron microscopy of substructures in Stillwater bytownites. In: MacKenzie WS, Zussman J (eds) The Feldspars. Manchester University Press, pp 522–535

  • Orville PM (1972) Plagioclase cation exchange equilibria with aqueous chloride solution: results at 700° C and 2,000 bars in the presence of quartz. Am J Sci 272:234–272

    Google Scholar 

  • Orville PM (1974) The “peristerite gap” as an equilibrium between ordered albite and disordered plagioclase solid solution. Bull Soc fr Minéral Cristallogr 97:386–392

    Google Scholar 

  • Rainey CS, Wenk H-R (1978) Intensity differences of subsidiary reflections in calcic plagioclase. Am Mineral 63:124–131

    Google Scholar 

  • Shiba H, Ishibashi Y (1978) Incommensurate-commensurate phase transitions in ferroelectric substances. J Phys Soc Jap 44:1592–1599

    Google Scholar 

  • Slimming EH (1976a) Electron optical studies of the feldspars. Ph.D Thesis, University of Cambridge

  • Slimming EH (1976b) An electron diffraction study of some intermediate plagioclases. Am Mineral 61:54–59

    Google Scholar 

  • Smith JV (1972) Critical review of synthesis and occurrence of plagioclase feldspars and a possible phase diagram. J Geol 80:505–525

    Google Scholar 

  • Smith JV (1974) Feldspar minerals, Vol. 1. Springer-Verlag, Berlin Heidelberg New York

    Google Scholar 

  • Smith JV (1975) Phase equilibria of plagioclase. In: Ribbe PH (ed) Reviews in Mineralogy, Vol. 2, Feldspar Mineralogy. Mineralogical Society of America

  • Smith JV (1983) Phase equilibria of plagioclase. In: Ribbe PH (ed) Reviews in Mineralogy, Vol. 2, 2nd edition, Feldspar Mineralogy. Mineralogical Society of America, pp 223–239

  • Smith JV (1984) Phase relations of plagioclase feldspars. In: Brown WL (ed) Feldspars and Feldspathoids. NATO ASI series C, Vol. 137. Reidel, Dordrecht Boston Lancaster, pp 55–94

    Google Scholar 

  • Smith JV, Gay P (1958) The powder patterns and lattice parameters of plagioclase feldspars II. Mineral Mag 31:744–762

    Google Scholar 

  • Smith JV, Ribbe PH (1969) Atomic movements in plagioclase feldspars: kinetic interpretation. Contrib Mineral Petrol 21:157–202

    Google Scholar 

  • Stewart DB, Walker GW, Wright TL, Fahey JJ (1966) Physical properties of calcic labradorite from Lake County, Oregon. Am Mineral 51:177–197

    Google Scholar 

  • Tagai T, Korekawa M (1981) Crystallographic investigation of the Huttenlocher exsolution at high temperature. Phys Chem Minerals 7:77–81

    Google Scholar 

  • Wenk H-R 1966 Labradorite from Surtsey (Iceland). Schweiz Mineral Petrogr Mitt 46:81–84

    Google Scholar 

  • Wenk H-R (1978) Ordering of the intermediate plagioclase structure during heating. Am Mineral 63:132–135

    Google Scholar 

  • Wenk H-R (1979a) Superstructure variation in metamorphic intermediate plagioclase. Am Mineral 64:71–76

    Google Scholar 

  • Wenk H-R (1979b) An albite-anorthite assemblage in low-grade amphibolite facies rocks. Am Mineral 64:1294–1299

    Google Scholar 

  • Wenk H-R, Joswig W, Tagai T, Korekawa M, Smith BK (1980) The average structure of An62–66 labradorite. Am Mineral 65:81–95

    Google Scholar 

  • Wenk H-R, Nakajima Y (1979) Periodic superstructures in calcic plagioclase. In: Cowley JM, Cohen JB, Salamon MB, Wuensch BJ (eds) Modulated Structures. American Institute of Physics, New York, pp 317–320

    Google Scholar 

  • Wenk H-R, Nakajima Y (1980) Structure, formation, and decomposition of APB's in calcic plagioclase. Phys Chem Minerals 6:169–186

    Google Scholar 

  • Wenk E, Wenk H-R (1977) An-variations and intergrowths of plagioclases in banded metamorphic rocks form Val Carecchio (Central Alps). Schweiz Mineral Petrogr Mitt 57:41–57

    Google Scholar 

  • Wilkins RWT, Sabine W (1973) Water content of some nominally anhydrous silicates. Am Mineral 58:508–516

    Google Scholar 

  • Windom KE, Boettcher AL (1976) The effect of reduced activity of anorthite on the reaction grossular + quartz = anorthite + wollastonite: a model for plagioclase in the earth's lower crust and upper mantle. Am Mineral 61:889–896

    Google Scholar 

  • Yund RA, Tullis J (1980) The effect of water, pressure and strain on Al/Si order-disorder kinetics in feldspar. Contrib Mineral Petrol 72:297–302

    Google Scholar 

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  1. Department of Earth Sciences, University of Cambridge, Downing Street, CB2 3EQ, Cambridge, U.K.

    Michael A. Carpenter

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Carpenter, M.A. Experimental delineation of the “e” ⇌ I\(\bar 1\) and “e” ⇌ C\(\bar 1\) transformations in intermediate plagioclase feldspars. Phys Chem Minerals 13, 119–139 (1986). https://doi.org/10.1007/BF00311902

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