Petrogenesis of lunar mare basalt meteorite Miller Range 05035     

Yang LIU  Christine FLOSS  James M. D. DAY  Eddy HILL  Lawrence A. TAYLOR 《Meteoritics & planetary science》2009,44(2):261-284

Abstract— Miller Range (MIL) 05035 is a low‐Ti mare basalt that consists predominantly of pyroxene (62.3 vol%) and plagioclase (26.4 vol%). Pyroxenes are strongly shocked and complexly zoned from augite (Wo₃₃) and pigeonite (Wo₁₇) cores with Mg# = 50–54 to hedenbergite rims. Coexisting pyroxene core compositions reflect crystallization temperatures of 1000 to 1100 °C. Plagioclase has been completely converted to maskelynite with signs of recrystallization. Maskelynite is relatively uniform in composition (An₉₄Ab₆–An₉₁Ab₉), except at contacts with late‐stage mesostasis areas (elevated K contents, An₈₂Ab₁₅Or₃). Symplectites (intergrowth of Fe‐augite, fayalite, and silica) of different textures and bulk compositions in MIL 05035 suggest formation by decomposition of ferro‐pyroxene during shock‐induced heating, which is supported by the total maskelynitization of plagioclase, melt pockets, and the presence of a relict pyroxferroite grain. Petrography and mineral chemistry imply that crystallization of MIL 05035 occurred in the sequence of Fe‐poor pyroxenes (Mg# = 50–54), followed by plagioclase and Fe‐rich pyroxenes (Mg# = 20–50), and finally hedenbergite, Fe‐Ti oxides, and minor late‐stage phases. Petrography, bulk chemistry, mineral compositions, and the age of MIL 05035 suggest it is possibly source crater‐paired with Asuka (A‐) 881757 and Yamato (Y‐) 793169, and may also be launch‐paired with Meteorite Hills (MET) 01210. MIL 05035 represents an old (?3.8–3.9 Ga), incompatible element‐depleted low‐Ti basalt that was not sampled during the Apollo or Luna missions. The light‐REE depleted nature and lack of Eu anomalies for this meteorite are consistent with an origin distant from the Procellarum KREEP Terrane, and genesis from an early cumulate mantle‐source region generated by extensive differentiation of the Moon.  相似文献   

Mapping Coastal Aquifers by Joint Inversion of DC and TEM Soundings-Three Case Histories     

Yves Albouy  Pierre Andrieux  Gérard Rakotondrasoa  Michel Ritz  Marc Descloitres  Jean-Lambert Join  Eddy Rasolomanana 《Ground water》2001,39(1):87-97

Electrical and electromagnetic methods are well suited for coastal aquifer studies because of the large contrast in resistivity between fresh water-bearing and salt water-bearing formations. Interpretation models for these aquifers typically contain four layers: a highly resistive unsaturated zone; a surficial fresh water aquifer of intermediate resistivity; an underlying conductive, salt water saturated aquifer; and resistive substratum. Additional layers may be added to allow for variations in lithology within the fresh water and salt water layers. Two methods are evaluated: direct current resistivity and time domain electromagnetic soundings. Use of each method alone produces nonunique solutions for resistivities and/or thicknesses of the different layers. We show that joint inversion of vertical electric and time domain electromagnetic soundings produces a more tightly constrained interpretation model at three test sites than is produced by inversion methods applied to each data set independently.  相似文献   

The solar constant — An editorial     

John A. Eddy 《Climatic change》1983,5(3):207-209

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Wind forcing of internal waves in a long narrow stratified lake     

Craig Stevens  Gregory Lawrence  Paul Hamblin  Eddy Carmack 《Dynamics of Atmospheres and Oceans》1996,24(1-4)

A vertically integrated approach to the analysis of thermistor chain and wind data from a long, narrow, stratified lake indicates that forcing events are short relative to the response time. Correlations between forcing and isotherm tilts clearly indicate stratification response times dependent on internal wave speed. In addition, it is possible to infer basin-scale internal wave damping where over 80% of the potential energy in the internal wave setup is lost in one internal wave period.  相似文献   

La prospection gravimétrique dans la modélisation d'un substratum sous formation sédimentaire : apport à l'hydrogéologie d'une zone semi-aride du Sud de Madagascar     

Heritiana Rakoto  Pierre Andrieux  Jean-Bruno Ratsimbazafy  Vittorio Iliceto  Eddy Rasolomanana  Louis Pastor  Gian Maria Zuppi 《Comptes Rendus Geoscience》2003,335(4):355-363

A gravimetric survey has been carried out in a sedimentary basin, south of Madagascar, in order to define the bedrock morphology. The bedrock is made up of crystalline and volcanic rocks. The objective of the survey was to demonstrate whether a relationship could be established between bedrock morphology and groundwater mineralisation. Indeed, bedrock morphology has been successfully mapped and it is confirmed that most of the low mineralisation wells are located in areas where the slope of the bedrock is trending to the south-west, which ensures a higher hydraulic conductivity, i.e. a faster water flow, than in the other parts of the survey area. To cite this article: H. Rakoto et al., C. R. Geoscience 335 (2003).  相似文献   

Obituary     

J. A. Eddy  R. M. MacQueen 《Solar physics》1986,104(2):257-258

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Baseline study of perfluorooctane sulfonate occurrence in mussels, Mytilus galloprovincialis, from north-central Portuguese estuaries     

Cunha I  Hoff P  Van de Vijver K  Guilhermino L  Esmans E  De Coen W 《Marine pollution bulletin》2005,50(10):1128-1132

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SEDIMENT TRANSPORT PROCESSES IN AGRICULTURAL WATERSHEDS     

Roger A. Kuhnle  Sean J. Bennett  Carlos V. Alonso  Ronald L. Bingner  Eddy Langendoen 《国际泥沙研究》2000,(2)

lINTR0DUCTI0NTheerosion,transportanddep0siti0nofsedimentinawatershedarepallofthenaturalsystemofwatershedprocesses.InanundistUrbedwatershed,s0ilsinuplandareasaregraduallyeroded,transportCdforsomedistanceandeventuallydepositedatlowereIevations.WhenwatershedsaredistUrbedbyhumanactivitiessuchasclearingofvegetation,urbaniZati0n,orotherchangesthataffectthelandscaPe,unstablechannelswithlocallyhighratesoferosion,transport,0rdepositionofsedimentoftenaretheresult.Theimpact0fer0sionisespeciallyhigh…  相似文献   

Water circulation control on carbonate-δO records in a low permeability clay formation and surrounding limestones: The Upper Dogger–Oxfordian sequence from the eastern Paris basin, France     

Vronique Lavastre  Magali Ader  Stphane Buschaert  Eddy Petit  Marc Javoy 《Applied Geochemistry》2011,26(5):818-827

Upper Dogger to Oxfordian Formations in the eastern part of the Paris basin (France) are currently being investigated by the French nuclear waste management agency (Andra), testing the feasibility of long-term deep nuclear waste disposal in the Callovo-Oxfordian claystones. Characterising the hydrogeological behaviour of the Callovo-Oxfordian claystones is, therefore, essential in evaluating its potential as a geological barrier. In order to evaluate and quantify water/rock interactions experienced over geological time by these Formations, bulk carbonate δ¹³C and δ¹⁸O were measured and calculations of water-rock ratios were used to explain carbonate-δ¹⁸O changes. Meteoric porewater and a maximum temperature reached of about 40 °C were considered. The Jurassic marine carbonate δ¹³C was preserved in the Callovo-Oxfordian claystones and in the overlying limestones (−0.28‰ to 3.39‰/PDB), while the δ¹⁸O values are lower by 0-5‰ (−6.25‰ to −1.32‰/PDB). Calculations show that Upper Dogger and Oxfordian Limestone δ¹⁸O data:

(i)

have random-like distribution through theoretical δ¹⁸O-W/R curves and

(ii)

suggest that water/rock ratios (0.08-0.4) needed to explain δ¹⁸O changes are higher by a factor of about 2-20 compared to the present-day water/rock ratio.

These features indicate advection in both aquifers. According to the history of the Paris basin, this hydrogeological behaviour could have been effective since Jurassic/Cretaceous transition times. Inversely, the carbonate-δ¹⁸O content trends observed for the Callovo-Oxfordian data show that changes were controlled by post-depositional fluid-rock interaction with water/rock ratio (0.02-0.15) similar to the present-day porewater/rock ratio. The 130 m thick Callovo-Oxfordian claystone appears remarkably homogenous regarding its hydrogeological properties. This study suggests an initial marine porewater replacement by meteoric water only after porosity was reduced to its present value, thus demonstrating that the Callovo-Oxfordian clay has mainly been isolated from advective meteoric water circulation. Only the upper 20 m of the Callovo-Oxfordian claystone Formation underwent heterogeneous water-rock exchange (W/R from 0.01 to 0.3), probably as a result of its mineralogical heterogeneity and proximity to the advective Oxfordian Limestone aquifer.This study of carbonate-δ¹⁸O confirms the hydrogeological barrier properties of the Callovo-Oxfordian clay and suggests that it has been a natural hydrological barrier since the earliest times of its diagenesis.  相似文献   

Variability of baroclinic tidal currents on the Mackenzie Shelf,the Southeastern Beaufort Sea     

Evgueni A. Kulikov  Alexander B. Rabinovich  Eddy C. Carmack 《Continental Shelf Research》2010

Semidiurnal tidal currents on the outer shelf of the Mackenzie Shelf in the Beaufort Sea were found to be strongly influenced by the locally generated baroclinic tide. Two primary factors are involved in this process: (1) the sharp shelf break along the northeastern Mackenzie Shelf, promoting the generation of vigorous internal tidal waves; and (2) the proximity to critical latitudes for M₂ and N₂ motions locking these waves and preventing them from leaving the source region. As a result, internal tides are resonantly trapped between the shelf and critical latitudes. The physical properties and temporal variations of tidal motions were examined using current meter measurements obtained from 1987–1988 at four sites (SS1, SS2, SS3, and SS4) offshore of the shelf break at depths of ∼200 m. Each mooring had Aanderaa RCM4s positioned at ∼35 m below the surface and ∼50 m above the bottom. Complex demodulation was used to compute the envelopes (amplitude modulation) of these components. A striking difference in the variability of clockwise (CW) and counterclockwise (CCW) tidal currents was found. The CW tides are highly variable, have greater amplitude, exhibit a burst-like character associated with wind events and contain about 80% of the total energy of the semidiurnal tidal currents. In contrast, the CCW components have a more regular temporal regime with distinct monthly, fortnightly and 10-day modulation at astronomical periodicities associated with frequency differences M₂–N₂ (0.03629 cpd), S₂–M₂ (0.06773 cpd), and S₂–N₂ (0.10402 cpd). Significant horizontal correlation of the CW current envelopes was found only between stations near the northeast Mackenzie Shelf, indicating this to be the main area of baroclinic internal wave generation.  相似文献