Evidence for the trapped liquid shift effect in the Mount Ayliff Intrusion,South Africa   总被引：1，自引：2，他引：1  

R. Grant Cawthorn  Bernhard K. Sander  Ian M. Jones 《Contributions to Mineralogy and Petrology》1992,111(2):194-202

Postcumulus trapped liquid shift in layered complexes produces cumulate minerals with more fractionated compositions than the original primary phases. This effect is shown by olivine compositions from the base of the Mount Ayliff Intrusion, where varying proportions of olivine to interstitial liquid produce a suite of rocks which define a tight linear trend on a binary whole-rock plot of MgO versus FeO. Extrapolation of this trend constrains the composition of the primary cumulus olivine to the range Fo_84–86, whereas olivine actually present have compositions Fo_77–83. The magnitude of the discrepancy between the theoretical and observed olivine compositions correlates directly with the weight fraction of interstitial liquid. These observations are quantitatively predicted by the trapped liquid shift model. They also argue against significant migration of residual liquid. Trapped liquid shift is documented over a vertical interval of 60 m. It occurred in rocks lying only 1 m above the basal contact of the intrusion and hence must be a comparatively rapid process.  相似文献   

Soviet sea otters increase     

M. Grant Gross 《Marine pollution bulletin》1973,4(9):131

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Geology and physics of the moon: A study of some fundamental problems: edited by G. Fielder. Elsevier,Amsterdam, 1971, 167 pp. $22.00     

Grant Heiken  Wendell Mendell 《Geochimica et cosmochimica acta》1973,37(5):1407-1408

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The composition and origin of the moon     

Don L. Anderson 《Earth and Planetary Science Letters》1973,18(2):301-316

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Pacific Science Association Congress     

A. Grant Anderson 《The Professional geographer》1983,35(4):476-476

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VEGETATION PRODUCTIVITY AND THE POTENTIAL POPULATION OF THE CLASSIC MAYA     

Steven L. Driever  B.A.  M.S.  Ph.D.  Don R. Hoy  B.A.  M.A.  Ph.D. 《Singapore journal of tropical geography》1984,5(2):140-153

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Modeling Forest Emissivity at L-Band and a Comparison With Multitemporal Measurements     

Della Vecchia  A. Ferrazzoli  P. Wigneron  J.-P. Grant  J.P. 《Geoscience and Remote Sensing Letters, IEEE》2007,4(4):508-512

This letter describes recent advances in modeling forest emissivity at L-band. The formulation is based on a previously developed discrete model and includes a new representation of forest litter. Comparisons with multitemporal radiometric data collected in the framework of the ldquoBray 2004rdquo experiment, which was carried out within Les Landes forest, are shown and discussed. Input variables are given by using detailed ground measurements. In general, the model reproduces both absolute values and temporal variations of measured brightness temperature. The contribution of the litter to overall emission was found to be important.  相似文献   

The detection of binary companions to subdwarf B stars     

C. Simon Jeffery  & Don L. Pollacco 《Monthly notices of the Royal Astronomical Society》1998,298(1):179-184

Intermediate dispersion spectroscopy of a sample of 40 hot subdwarf B stars between 5500 and 9000Å has been obtained. The sample includes a large fraction of targets which have been studied photometrically. Seven targets show strong lines arising from the infrared Ca  ii triplet, the unequivocal signature of a cool companion. The positive Ca  ii identifications include known photometric binaries and new targets; all are associated with a photometric red excess. Assuming a canonical value for the subdwarf luminosity, all of the detected companions are overluminous compared with the main sequence. The detection procedure indicates an improved and more secure method for the measurement of the binary frequency of hot subdwarfs.  相似文献   

Recently increased tropical cyclone activity and inferences concerning coastal erosion and inland hydrological regimes in New Zealand and Eastern Australia     

Patrick J. Grant 《Climatic change》1981,3(3):317-332

For the area bounded by 0–35 °S latitude and 105 °E–105 °W longitude a significant increase of tropical cyclone frequency occurred about 1954–55 and this regime persisted throughout the 1960s and 1970s. Probably this frequency increase was accompanied by an increase of cyclonic storm intensity. It was related to an atmospheric pressure regime change over Australasia which commenced in early 1954. Tropical cyclones produce large rainfall amounts and strong winds which generate high-energy sea waves. Severe damage can result on land and at sea. However, much recently recorded damage has resulted from extra-tropical cyclones. Therefore it is postulated that extra-tropical cyclones also increased in frequency after the mid 1950s and that both types of cyclone contributed to a significant increase in total storminess. In eastern Australia and around both islands of New Zealand a major coastal regime change occurred in the 1950s and has persisted to the present;erosion has been the dominant process. In eastern Australia there was a significant increase in the magnitude of river floods after the late 1940s. After the mid 1950s most of the North Island of New Zealand experienced the wettest years of this century which caused large closed lakes to reach the highest levels for several centuries. Throughout the North Island the majority of the greatest recorded stream floods of this century have occurred during the 1950s, 1960s and 1970s. And in forested mountain areas of the North Island the average rate of erosion and alluvial sedimentation increased markedly after the mid 1950s. The regime change of each natural phenomenon is explicable in terms of increased storminess since the mid 1950s. Consequently it is hypothesised that the coastal and inland environmental regime changes discussed were either initiated or accentuated after the mid 1950s as a result of increased activity of both tropical and extra-tropical cyclones. Some further studies, necessary to test the links in the overall hypothesis, are mentioned.  相似文献   

The impact of drilling fluid and well cuttings on polychaete feeding guilds from the US northeastern continental shelf     

Don Maurer  Wayne Leathem  Charles Menzie 《Marine pollution bulletin》1981,12(10):342-347

The effect of recent drilling operations (fluid and well cuttings) on polychaete feeding guilds from the continental shelf off Atlantic City, New Jersey, was examined. Although there were some adverse effects on macrobenthos from 2160 metric tons of cuttings and mud solids discharged into the marine environment, the composition of polychaete feeding guilds remained essentially unchanged. This key trophic relationship between polychaetes and the changing environment due to the drilling operation was apparently uninterrupted. This relationship remains to be examined in other natural and perturbed habitats.  相似文献