Near-infrared spectroscopy of probable impact melt from three large lunar highland craters     

Suzanne Smrekar  Carle M. Pieters 《Icarus》1985,63(3):442-452

The composition of small areas within three large lunar highland craters are compared using near-infrared, Earth-based telescopic data. Spectra from many areas in the walls and central peaks of the craters indicate the presence of crystalline components which include olivine, two types of pyroxene, and sometimes Fe-bearing feldspar. Spectra from other regions suspected of being impact melt deposits, located on the floors and walls of the three craters, have remarkably similar, yet anomalous features. These features are interpreted to indicate the presence of pyroxene, Fe-bearing glass, and Fe-bearing feldspar. Pyroxene and feldspar are believed to occur primarily in the form of lithic clasts and rapidly recrystallized impact melt. The Fe-bearing glass is interpreted as impact melt glass.  相似文献   

Radiative transfer in disc galaxies – III. The observed kinematics of dusty disc galaxies     

Maarten Baes †  Jonathan I. Davies  Herwig Dejonghe  Sabina Sabatini  Sarah Roberts  Rhodri Evans  Suzanne M. Linder  Rodney M. Smith  W. J. G. de Blok 《Monthly notices of the Royal Astronomical Society》2003,343(4):1081-1094

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The Monitor project: rotation of low-mass stars in the open cluster M34     

Jonathan Irwin  Suzanne Aigrain  Simon Hodgkin  Mike Irwin  Jerome Bouvier  Cathie Clarke  Leslie Hebb  Estelle Moraux 《Monthly notices of the Royal Astronomical Society》2006,370(2):954-974

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Episodic refertilization and metasomatism of Archean mantle: evidence from an orogenic peridotite in North Qaidam (NE Tibet,China)     

Qing Xiong  William L. Griffin  Jian-Ping Zheng  Suzanne Y. O’Reilly  Norman J. Pearson 《Contributions to Mineralogy and Petrology》2015,169(3):1-24

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Carbonate-hosted nonsulphide Zn–Pb mineralization of southern British Columbia,Canada     

Suzanne Paradis  Halley Keevil  George J. Simandl  Mati Raudsepp 《Mineralium Deposita》2015,50(8):923-951

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Disaster recovery as participation: lessons from the Shaky Isles     

Vallance  Suzanne 《Natural Hazards》2015,75(2):1287-1301

Natural Hazards - Despite broad scholarly consensus that public participation in disaster recovery is highly desirable, in practice, appropriate and effective forms of community involvement are...  相似文献   

Geochronological (U–Pb,U–Th–total Pb,Sm–Nd) and geochemical (REE, <Superscript>87</Superscript>Sr/<Superscript>86</Superscript>Sr, δ<Superscript>18</Superscript>O, δ<Superscript>13</Superscript>C) tracing of intraplate tectonism and associated fluid flow in the Warburton Basin,Australia     

Alexander?W.?MiddletonEmail author  I.?Tongu??Uysal  Suzanne?D.?Golding  Hans-Jürgen?F?rster  Charlotte?M.?Allen  Yeuxing?Feng  Dieter?Rhede  Vicki?J.?Marshall  Jaco?van?Zyl 《Contributions to Mineralogy and Petrology》2014,168(3):1058

The Warburton Basin of central Australia has experienced a complex tectonic and fluid-flow history, resulting in the formation of various authigenic minerals. Geochemical and geochronological analyses were undertaken on vein carbonates from core samples of clastic sediments. Results were then integrated with zircon U–Pb dating and uraninite U–Th–total Pb dating from the underlying granite. Stable and radiogenic isotopes (δ¹⁸O, Sr and εNd), as well as trace element data of carbonate veins indicate that >200 °C basinal fluids of evolved meteoric origin circulated through the Warburton Basin. Almost coincidental ages of these carbonates (Sm–Nd; 432 ± 12 Ma) with primary zircon (421 ± 3.8 Ma) and uraninite (407 ± 16 Ma) ages from the granitic intrusion point towards a substantial period of active tectonism and an elevated thermal regime during the mid Silurian. We hypothesise that such a thermal regime may have resulted from extensional tectonism and concomitant magmatic activity following regional orogenesis. This study shows that the combined application of geochemical and geochronological analyses of both primary and secondary species may constrain the timing of tectonomagmatic events and associated fluid flow in intraplate sedimentary basins. Furthermore, this work suggests that the Sm–Nd-isotopic system is surprisingly robust and can record geologically meaningful age data from hydrothermal mineral species.  相似文献   

SURVEYORS OF EMPIRE: Samuel Holland,J.F.W. Des Barres,and the Making of The Atlantic Neptune. By Stephen J. Hornsby     

Suzanne Zeller 《Geographical review》2013,103(1):126-128

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Life Histories, Salinity Zones, and Sublethal Contributions of Contaminants to Pelagic Fish Declines Illustrated with a Case Study of San Francisco Estuary, California, USA     

Marjorie L. Brooks  Erica Fleishman  Larry R. Brown  Peggy W. Lehman  Inge Werner  Nathaniel Scholz  Carys Mitchelmore  James R. Lovvorn  Michael L. Johnson  Daniel Schlenk  Suzanne van Drunick  James I. Drever  David M. Stoms  Alex E. Parker  Richard Dugdale 《Estuaries and Coasts》2012,35(2):603-621

Human effects on estuaries are often associated with major decreases in abundance of aquatic species. However, remediation priorities are difficult to identify when declines result from multiple stressors with interacting sublethal effects. The San Francisco Estuary offers a useful case study of the potential role of contaminants in declines of organisms because the waters of its delta chronically violate legal water quality standards; however, direct effects of contaminants on fish species are rarely observed. Lack of direct lethality in the field has prevented consensus that contaminants may be one of the major drivers of coincident but unexplained declines of fishes with differing life histories and habitats (anadromous, brackish, and freshwater). Our review of available evidence indicates that examining the effects of contaminants and other stressors on specific life stages in different seasons and salinity zones of the estuary is critical to identifying how several interacting stressors could contribute to a general syndrome of declines. Moreover, warming water temperatures of the magnitude projected by climate models increase metabolic rates of ectotherms, and can hasten elimination of some contaminants. However, for other pollutants, concurrent increases in respiratory rate or food intake result in higher doses per unit time without changes in the contaminant concentrations in the water. Food limitation and energetic costs of osmoregulating under altered salinities further limit the amount of energy available to fish; this energy must be redirected from growth and reproduction toward pollutant avoidance, enzymatic detoxification, or elimination. Because all of these processes require energy, bioenergetics methods are promising for evaluating effects of sublethal contaminants in the presence of other stressors, and for informing remediation. Predictive models that evaluate the direct and indirect effects of contaminants will be possible when data become available on energetic costs of exposure to contaminants given simultaneous exposure to non-contaminant stressors.  相似文献   

Melt/mantle mixing produces podiform chromite deposits in ophiolites: Implications of Re-Os systematics in the Dongqiao Neo-tethyan ophiolite, northern Tibet   总被引：8，自引：0，他引：8  

Rendeng Shi  William L. Griffin  Suzanne Y. O'ReillyQishuai Huang  Xiaoran ZhangDeliang Liu  Xiachen ZhiQiongxia Xia  Lin Ding 《Gondwana Research》2012,21(1):194-206

Podiform chromite deposits occur in the mantle sequences of many ophiolites that were formed in supra-subduction zone (SSZ) settings. We have measured the Re-Os isotopic compositions of the major chromite deposits and associated mantle peridotites of the Dongqiao Ophiolite in the Bangong-Nujiang suture, Tibet, to investigate the petrogenesis of these rocks and their genetic relationships.The ¹⁸⁷Os/¹⁸⁸Os ratios of the chromite separates define a narrow range from 0.12318 to 0.12354, less variable than those of the associated peridotites. Previously-reported ¹⁸⁷Os/¹⁸⁸Os ratios of the Os-rich alloys enclosed in the chromitites define two clusters: 0.12645 ± 0.00004 (2 s; n = 145) and 0.12003 to 0.12194. The ultra-depleted dunites have much lower ¹⁸⁷Os/¹⁸⁸Os (0.11754, 0.11815), and the harzburgites show a wider range from 0.12107 to 0.12612. The average isotopic composition of the chromitites (¹⁸⁷Os/¹⁸⁸Os: 0.12337 ± 0.00001) is low compared with the carbonaceous chondrite value (¹⁸⁷Os/¹⁸⁸Os: 0.1260 ± 0.0013) and lower than the average value measured for podiform chromitites worldwide (0.12809 ± 0.00085). In contrast, the basalts have higher ¹⁸⁷Os/¹⁸⁸Os, ranging from 0.20414 to 0.38067, while the plagioclase-bearing harzburgite and cumulates show intermediate values of ¹⁸⁷Os/¹⁸⁸Os (0.12979 ~ 0.14206). Correspondingly, the basalts have the highest ¹⁸⁷Re/¹⁸⁸Os ratios, up to 45.4 ± 3.2, and the chromites have the lowest ¹⁸⁷Re/¹⁸⁸Os ratios, down to 0.00113 ± 0.00008. We suggest that melts/fluids, derived from the subducting slab, triggered partial melting in the overlying mantle wedge and added significant amounts of radiogenic Os to the peridotites. Mass-balance calculations indicate that a melt/mantle ratio of approximately 15:1 (melt: ¹⁸⁷Re/¹⁸⁸Os: 45.4, ¹⁸⁷Os/¹⁸⁸Os: 0.34484; mantle peridotite: ¹⁸⁷Re/¹⁸⁸Os: 0.0029, ¹⁸⁷Os/¹⁸⁸Os: 0.11754) is necessary to increase the Os isotopic composition of the chromitite deposits to its observed average value. This value implies a surprisingly low average melt/mantle ratio during the formation of the chromitite deposits. The percolating melts probably were of variable isotopic composition. However, in the chromitite pods the Os from many melts was pooled and homogenized, which is why the chromitite deposits show such a small variation in their Os isotopic composition. The results of this study suggest that the ¹⁸⁷Os/¹⁸⁸Os ratios of chromitites may not be representative of the DMM, but only reflect an upper limit. Importantly, the Os-isotope compositions of chromitites strongly suggest that such deposits can be formed by melt/mantle mixing processes.  相似文献