Partition coefficients in the Fe-Ni-S-P system measured utilizing "static" equilibration experiments cannot be reconciled with the results of "dynamic" experiments which mimic fractional crystallization. New tests of the "static" experiments demonstrate that they yield reliable equilibrium Ni, P and Ge partition coefficients. Partition coefficients in the Fe-Ni-S-P system are well matched by interpolation between the Fe-Ni-S and Fe-Ni-P subsystems. The crystal/liquid partitioning of Ga and Ge has been measured experimentally between forsterite, diopside, anorthite and spinel and melts in the forsterite-diopside-anorthite system. The coefficients for the exchange of Ga and Al and the exchange of Ge and Si between minerals and melts are within a factor of two of unity. Application of these results to the interpretation of natural basaltic samples demonstrates that Ga/Al and Ge/Si ratios can be used to discriminate between different mantle source regions.

323 p. : ill., photos., tables, 5 journal reprints in end pocket ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 1980

323 p. : ill., photos., tables, 5 journal reprints in end pocket ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 1980

To constrain the thermal histories of two complex L chondrite melt breccia samples (NWA 5964 and NWA 6580) we compare textures and chemical compositions of metal and sulfide to L melt rock (NWA 6454 and NWA 6579) and strongly shocked (shock stage S6) (NWA 4860) samples. The inferred thermal histories can be used to evaluate formation settings on the L chondrite parent body. The L melt samples probably formed as different melt units within warm but largely unmelted material relatively close to the surface of the parent body, and the same is true for the S6 sample, except it experienced less melting. The breccia samples likely formed deeper, below different impact craters, by the injection of shock melt into a cooler chondritic basement. Carbide grains in the melt breccias could have formed by a contact metamorphic process caused by heating of the chondritic basement in proximity to the melt. Within the melt regions of the various samples, inferred cooling rates are on the order of 1-10 °C/sec, whereas in the chondritic portions of the melt breccias, the inferred cooling rates are many orders of magnitude slower, ~1-100 °C/My. The complex intergrowths of metal and FeS (hereafter referred to as dendritic grains) within the melt are recording cooling rates above the metal-sulfide eutectic, while the metal grains outside of the melt regions are recording cooling rates at much lower temperatures. It is likely the melt regions in the breccias cooled substantially prior to coming to rest against the chondritic basement, and thereafter the melt-chondrite rocks cooled more slowly.

Our inventory of material from the early solar system includes large, igneous-textured inclusions in O chondrites, whose origin and relationship to their host meteorite is unclear. These inclusions occur in approximately 4% of O chondrites, and are mineralogically, petrographically, and chemically diverse. Petrographic and chemical data from 29 inclusions from 23 host meteorites were collected with optical light and scanning electron microscopy, allowing for the determination of major phase modal abundance and major element bulk chemistry. No correlation between any inclusion property and host meteorite type were found, but some trends were observed. Nine of the inclusions show strong evidence, such as radial variations in texture and chemistry, for having crystallized as a free-floating droplet in a space environment, and may share the same formation process as chondrules. One inclusion is almost certainly shock-melted material that intruded into the host material. Thirteen inclusions have bulk chemistry patterns that suggest the material was vapor fractionated; the remaining sixteen are essentially chondritic, i.e., unfractionated. Broadly, the data support the conclusions of Ruzicka et al. (1998, 2000), which divided large inclusions into Na-poor (vapor fractionated) and Na-rich (unfractionated) groups, suggesting at least two different origins. There is no evidence that any of the inclusions studied formed by igneous differentiation.

"July 2003." Includes bibliographical references (leaves 459-484) Electronic publication; full text available in PDF format; abstract in HTML format. Details the application of a medium frequency Doppler radar to observations of meteorites entering the Earth's atmosphere. Techniques were developed that verified system performance was to specification Electronic reproduction.[Australia] :Australian Digital Theses Program,2001. xx, 485 leaves : ill. ; 30 cm.

The polymer-like organic material in the Orgueil (Cl) chondrite was analyzed by high vacuum pyrolysis/gas chromatography/mass spectrometry, a new technique specially developed for this type of polymer analysis. Orgueil powder, previously solvent-extracted to remove all soluble organic compounds, whether indigenous or contaminant, was pyrolyzed in temperature steps at 150°, 300°, 450°, and 600°C. Gas chromatographic/mass spectrometric analysis of the vacuum pyrolyzates revealed a series of alkenes to C₈, an extensive series of alkylbenzene isomers, thiophene, alkylthiophenes, and benzothiophene, and the nitrogen compounds acetonitrile, acrylonitrile, and benzonitrile. Comparison of the Orgueil polymer fragments with those reported in polymer analyses of the Murchison and Allende meteorites suggests that qualitatively and quantitatively the Orgueil and Allende polymeric materials are very similar. The presence of acetonitrile, acrylonitrile, and benzonitrile, typical breakdown products of amino acids, in Orgueil pyrolyzates suggests the presence of amino acids in an insoluble form in the meteorite polymer matrix. Changes in the distribution of polymer fragments occurred during high vacuum pyrolyses as the temperature was increased stepwise from 150° to 600°C. These changes imply a progressive alteration in the character of the polymeric material toward a condensed aromatic structure through the preferential loss of aliphatic and heteroaromatic portions at lower temperatures. A possible inference is that the polymeric material in Orgueil is a complex mixture of polymerized materials having different thermal stability. Comparison of vacuum pyrolyzates of the Orgueil polymeric material with pyrolyzates of terrestrial kerogen indicates similarities in composition and structure. These similarities suggest the possibility that meteorite polymers may have formed near the surfaces of meteorite parent bodies by low temperature processes similar to those by which terrestrial kerogen is formed.