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Journal articleWilliams W, Muxworthy AR, Paterson GA, 2006, , JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 111, ISSN: 2169-9313
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- Citations: 30
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Journal articleNielsen SG, Rehkamper M, Teagle DAH, et al., 2006, , EARTH AND PLANETARY SCIENCE LETTERS, Vol: 251, Pages: 120-133, ISSN: 0012-821X
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- Citations: 147
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Journal articleMorgan J V, Lana C, Kearsley A, et al., 2006,
Analyses of shocked quartz at the global K-P boundary indicate an origin from a single, high-angle, oblique impact at Chicxulub
, Earth and Planetary Science Letters, Vol: 251, Pages: 264-279, ISSN: 0012-821X -
Journal articleCarvallo C, Muxworthy A, 2006, , GEOCHEM GEOPHY GEOSY, Vol: 7, ISSN: 1525-2027
[ 1] First-order reversal curve (FORC) diagrams were measured on a variety of synthetic and natural ( submarine basalts and potsherds) samples, as well as for a mixture, between room temperature and 10 K. Measuring FORC diagrams allowed us to examine the behavior of the coercivity field and interaction field distributions with decreasing temperature. Generally, as the temperature is decreased, FORC contours were observed to expand in all directions, e. g., the maximum coercivity peak migrates toward a higher coercivity. For synthetic magnetite samples, there were abrupt changes in the FORC distribution at the Verwey transition ( 120 K), while in the more complex natural magnetite samples the FORC distribution gradually progressed with temperature. As the temperature decreased, FORC diagrams were found to display different domain state characteristics. For example, samples with dominant superparamagnetic signals became single-domain (SD)-like, a SD-like sample stayed SD-like, and a PSD-like sample became more SD-like. In addition to these general features, we also observed some more specialized features. First, in both synthetic and natural magnetite samples, a secondary higher-coercivity peak is occasionally present below the Verwey transition, which we suggest is a twinning contribution. Second, the coercivity increases by a factor 15 between 300 K and 20 K in some of the seamount samples. Third, the effect of field cooling/ zero-field cooling on FORC diagrams is negligible, with the hysteresis parameters HC and HCR displaying a greater dependency. Finally, it is shown that in mixtures of magnetite and hematite, the hematite contribution disappears on cooling below the Morin transition, leaving a strong, well-defined magnetite signal.
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Journal articleRao Y, Wang YH, Morgan JV, 2006, , Geophysical Journal International, Vol: 166, Pages: 1237-1248, ISSN: 1365-246X
In an accompanying paper, we used waveform tomography to obtain a velocity model between two boreholes from a real crosshole seismic experiment. As for all inversions of geophysical data, it is important to make an assessment of the final model, to determine which parts of the model are well-resolved and can confidently be used for geological interpretation. In this paper we use checkerboard tests to provide a quantitative estimate of the performance of the inversion and the reliability of the final velocity model. We use the output from the checkerboard tests to determine resolvability across the velocity model. Such tests can act as good guides for designing appropriate inversion strategies. Here we discovered that, by including both reference-model and smoothing constraints in initial inversions, and then relaxing the smoothing constraint for later inversions, an optimum velocity image was obtained. Additionally, we noticed that the performance of the inversion was dependent on a relationship between velocity perturbation and checkerboard grid-size: larger velocity perturbations were better-resolved when the grid-size was also increased. Our results suggest that model assessment is an essential step prior to interpreting features in waveform tomographic images.
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Journal articlePearson VK, Sephton MA, Gilmour I, 2006, , METEORITICS & PLANETARY SCIENCE, Vol: 41, Pages: 1291-1303, ISSN: 1086-9379
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- Citations: 17
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Conference paperRipperger S, Rehkaemper M, Halliday AN, 2006, , 16th Annual V M Goldschmidt Conference, Publisher: PERGAMON-ELSEVIER SCIENCE LTD, Pages: A535-A535, ISSN: 0016-7037
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Conference paperRehkamper M, Nielsen SG, Teagle DAH, et al., 2006, , 16th Annual V M Goldschmidt Conference, Publisher: PERGAMON-ELSEVIER SCIENCE LTD, Pages: A524-A524, ISSN: 0016-7037
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Conference paperZolensky M, Bland P, Bradley J, et al., 2006,
Mineralogy and petrology of Comet Wild-2 nucleus samples - Final results of the preliminary examination team
, 69th Annual Meeting of the Meteoritical Society, Publisher: METEORITICAL SOC, Pages: A167-A167, ISSN: 1086-9379- Cite
- Citations: 1
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Conference paperNielsen SG, Wood BJ, Rehkaemper M, et al., 2006,
An experimental study of thallium partitioning and isotope fractionation during planetary core formation processes
, 69th Annual Meeting of the Meteoritical Society, Publisher: METEORITICAL SOC, Pages: A131-A131, ISSN: 1086-9379 -
Conference paperPreston LJ, Genge MJ, Ghail R, 2006,
Microbial structures in hydrothermal deposits as biomarkers for Mars
, 69th Annual Meeting of the Meteoritical Society, Publisher: METEORITICAL SOC, Pages: A143-A143, ISSN: 1086-9379 -
Conference paperGenge MJ, 2006,
Equilibrated ordinary chondrite-like micrometeorites
, 69th Annual Meeting of the Meteoritical-Society, Publisher: WILEY, Pages: A62-A62, ISSN: 1086-9379 -
Conference paperBland PA, Jackson MD, Coker RF, et al., 2006,
Why asteroidal alteration was isochemical: High porosity not equal high permeability
, 69th Annual Meeting of the Meteoritical Society, Pages: A22-A22, ISSN: 1086-9379 -
Conference paperRehkaemper M, Nielsen SG, Williams HM, et al., 2006,
Radiogenic and stable thallium isotope variations in iron meteorites
, 69th Annual Meeting of the Meteoritical Society, Publisher: METEORITICAL SOC, Pages: A147-A147, ISSN: 1086-9379 -
Journal articlePerry RS, Sephton MA, 2006, , ASTRONOMY & GEOPHYSICS, Vol: 47, Pages: 34-35, ISSN: 1366-8781
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- Citations: 13
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Journal articleMuxworthy AR, Williams W, 2006, , JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 111, ISSN: 2169-9313
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- Citations: 13
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Journal articleFehr MA, Rehkaemper M, Halliday AN, et al., 2006, , GEOCHIMICA ET COSMOCHIMICA ACTA, Vol: 70, Pages: 3436-3448, ISSN: 0016-7037
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- Citations: 35
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Journal articleSephton MA, James RH, Zolensky ME, 2006, , METEORITICS & PLANETARY SCIENCE, Vol: 41, Pages: 1039-1043, ISSN: 1086-9379
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- Citations: 15
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Journal articleChironi C, Morgan JV, Warner MR, 2006, , JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 111, ISSN: 2169-9313
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- Citations: 15
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Journal articleNielsen SG, Rehk盲mper M, Halliday AN, 2006, , GEOCHIMICA ET COSMOCHIMICA ACTA, Vol: 70, Pages: 2643-2657, ISSN: 0016-7037
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- Citations: 59
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