Volatile element chemistry in the solar nebula: Na, K, F, Cl, Br, and P

The results of the most extensive set to date of thermodynamic calculations on the equilibrium chemistry of several hundred compounds of the elements Na, K, F, Cl, Br, and P in a solar composition system are reported. Two extreme models of accretion are investigated. In one extreme complete chemical equilibrium between condensates and gases is maintained because the time scale for accretion is long compared to the time scale for cooling or dissipation of the nebula. Condensates formed in this homogeneous accretion model include several phases such as whitlockite, alkali feldspars, and apatite minerals which are found in chondrites. In the other extreme complete isolation of newly formed condensates from prior condensates and gases occurs due to a time scale for accretion that is short relative to the time required for nebular cooling or dissipation. The condensates produced in this heterogeneous accretion model include alkali sulfides, ammonium halides, and ammonium phosphates. None of these phases are found in chondrites. Available observations of the Na, K, F, Cl, Br, and P elemental abundances in the terrestrial planets are found to be compatible with the predictions of the homogeneous accretion model.

[1]  B. Mason.  Cosmochemistry; Part 1, Meteorites , 1979 .

[2]  JOHN S. Lewis,et al.  Chemistry of Primitive Solar Material , 1976 .

[3]  R. Schmitt,et al.  The petrogenesis of L-6 chondrites: insights from the chemistry of minerals , 1979 .

[4]  R. A. McDonald,et al.  JANAF thermochemical tables, 1978 supplement , 1978 .

[5]  B. Mason,et al.  Minor and Trace Elements in Meteoritic Minerals , 1970 .

[6]  L. Kaplan,et al.  Traces of HCl and HF in the atmosphere of Venus , 1967 .

[7]  R. McDonald,et al.  THE THERMODYNAMIC PROPERTIES OF MAGNESIUM ORTHOPHOSPHATE AND MAGNESIUM PYROPHOSPHATE , 1963 .

[8]  JOHN S. Lewis.  Consequences of the presence of sulfur in the core of the earth , 1971 .

[9]  D. D. Wagman,et al.  Selected Values of Chemical Thermodynamic Properties. Tables for the Lanthanide (Rare Earth) Elements (Elements 62 through 76 in the Standard Order of Arrangement). , 1971 .

[10]  F. F. Kirnozov,et al.  Investigations of Venusian gamma-radiation by Venera 9 and Venera 10. , 1976 .

[11]  E. J. Duff.  Orthophosphates - XI Bromoapatite: Stability of solid solutions of bromoapatite with other calcium apatites under aqueous conditions , 1972 .

[12]  W. R. Schmus,et al.  Composition of phosphate minerals in ordinary chondrites , 1969 .

[13]  C. Wai,et al.  Nebular condensation of moderately volatile elements and their abundances in ordinary chondrites , 1976 .

[14]  E. Olsen,et al.  Origin of the high-temperature fraction of C2 chondrites , 1974 .

[15]  H. Wänke,et al.  Halogens in meteorites and their primordial abundances , 1979 .

[16]  J. Smith.  Possible controls on the bulk composition of the earth - Implications for the origin of the earth and moon , 1977 .

[17]  Kenneth C. Mills,et al.  Thermodynamic data for inorganic sulphides, selenides and tellurides , 1974 .

[18]  S. Saxena.  Thermodynamics of Rock-Forming Crystalline Solutions , 1973 .

[19]  A. N. Syverud,et al.  JANAF Thermochemical Tables, 1974 Supplement , 1974 .

[20]  L. Fuchs.  The Phosphate Mineralogy of Meteorites , 1969 .

[21]  L. Grossman.  Condensation in the primitive solar nebula , 1972 .

[22]  JOHN S. Lewis.  Metal/silicate fractionation in the solar system , 1972 .

[23]  D. D. Wagman,et al.  Selected Values of Chemical Thermodynamic Properties. Tables for the First Thirty-Four Elements in the Standard Order of Arrangement. , 1968 .

[24]  D. D. Wagman,et al.  Selected Values of Chemical Thermodynamic Properties. Tables for Elements 54 through 61 in the Standard Order of Arrangement. , 1971 .

[25]  F. F. Kirnozov,et al.  The Content of Uranium, Thorium, and Potassium in the Rocks of Venus as Measured by Venera 8 , 1973 .

[26]  A. Cameron.  Physics of the primitive solar nebula and of giant gaseous protoplanets , 1978 .

[27]  T. R. Wellman.  The vapor pleasure of NaCl over decomposing sodalite , 1969 .

[28]  A. K. Baird,et al.  Inorganic Analyses of Martian Surface Samples at the Viking Landing Sites , 1976, Science.

[29]  R. A. Robie,et al.  Thermodynamic properties of minerals and related substances at 298.15 K (25.0 C) and one atmosphere (1.013 bars) pressure and at higher temperatures , 1968 .

[30]  H. Leffmann.  Data of geochemistry: United States Geological Survey, Bulletin 695. By Frank Wigglesworth Clarke. 4th edition. 773 pages and index, 8vo. Washington, Government Printing Office, 1920 , 1920 .

[31]  A. Cameron,et al.  Abundances of the elements in the solar system , 1973 .

[32]  K. Turekian,et al.  Inhomogeneous accumulation of the earth from the primitive solar nebula. , 1969 .

[33]  L. Fuchs.  X-ray crystallographic evidence for the meteoritic occurrence of nepheline , 1968 .

[34]  JOHN S. Lewis,et al.  Primodial retention of carbon by the terrestrial planets , 1979 .

[35]  D. D. Wagman,et al.  Chemical Thermodynamic Properties of Compounds of Sodium, Potassium and Rubidium: An Interim Tabulation of Selected Values. , 1976 .

[36]  A. N. Syverud,et al.  JANAF thermochemical tables, 1975 supplement , 1975 .

[37]  JOHN S. Lewis.  The Temperature Gradient in the Solar Nebula , 1974, Science.

[38]  JOHN S. Lewis,et al.  Chemical structure of the deep atmosphere of Jupiter , 1978 .

[39]  W. R. Schmus,et al.  The composition and structural state of feldspar from chondritic meteorites , 1968 .

[40]  P. Spencer,et al.  A thermodynamic assessment of the iron-phosphorus system , 1978 .

[41]  D. Sears.  Condensation and the composition of iron meteorites , 1978 .

[42]  R. Allen,et al.  Fluorine in meteorites , 1977 .

[43]  P. M. Orville.  Plagioclase cation exchange equilibria with aqueous chloride solution; results at 700 degrees C and 2000 bars in the presence of quartz , 1972 .