The halogens in Luna 16 and Luna 20 soils     

G.W. Reed  S. Jovanovic 《Geochimica et cosmochimica acta》1973,37(4):1007-1009

Cl and P₂U₅ do not appear to exhibit the same correlation in soils from the Luna 20 and possibly the Luna 16 sites as they do in samples from the Apollo 11–15 sites. Nevertheless, the coherence between labile Cl and other KREEP-related elements is maintained.  相似文献   

Soil conservation: problems and prospects : Morgan, R.P.C. (ed.) Chichester: Wiley, 1981. 576 pp     

A. Harrison Reed 《Applied geography (Sevenoaks, England)》1982,2(4):317-318

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Compositions of magmatic hydrothermal fluids determined by LA-ICP-MS of fluid inclusions from the porphyry copper–molybdenum deposit at Butte, MT     

Brian G. Rusk  Mark H. Reed  John H. Dilles  Leonhard M. Klemm  Christoph A. Heinrich 《Chemical Geology》2004,210(1-4):173-199

We analyzed 85 fluid inclusions from seven samples from the porphyry Cu–Mo deposit in Butte, MT, using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The Butte deposit formed at unusually great depth relative to most porphyry deposits, and fluid inclusions in deep veins trapped a low-salinity, CO₂-bearing, magmatically derived, supercritical fluid as a single aqueous phase. This fluid is interpreted to be the parent fluid that cooled, decompressed, unmixed, and reacted with wall rock to form the gigantic porphyry Cu deposit at Butte. Few previous analyses of such fluids exist.Low-salinity, aqueous fluids from the earliest veins at Butte are trapped in deep veins with biotite-rich alteration envelopes (EDM veins). These veins, and the Butte quartz monzonite surrounding them, host much of the Butte porphyry Cu mineralization. Twenty fluid inclusions in one EDM quartz vein are dominated by Na, K, Fe (from 0.1 to 1 wt.%) and contain up to 1.3 wt.% Cu. These inclusions contain only small amounts (tens of ppm) of Pb, Zn, and Mn, and typically contain Li, B, Ca, As, Mo, Ag, Sn, Sb, Ba, and W in less than detectable quantities. The abundance of Cu in early fluids indicates that a low-salinity, Cu-rich, aqueous ore fluid can be directly produced by aqueous fluid separation from a granitic magma. Similar inclusions (eight) in an early deep quartz–molybdenite vein with a K-feldspar selvage have similar compositions but contain significantly less Cu than most inclusions in the biotite-altered vein. Analyzed inclusions in both veins contain less than detectable concentrations of Mo even though one is molybdenite-bearing.Low-salinity, CO₂-bearing aqueous fluids are also trapped in pyrite–quartz veins with sericitic selvages. These veins cut both of the above vein types and contain inclusions that were trapped at lower pressure and temperature. Thirty-nine inclusions in two such veins have compositions similar to early fluids, but are enriched by up to a factor of 10 in Mn, Pb, and Zn relative to early fluids, and are slightly depleted in Fe. Many of these inclusions contain as much or more Cu than early fluids, although little chalcopyrite is found in or around pyrite–quartz veins.Eighteen halite-bearing inclusions from three veins from both chalcopyrite-bearing and barren veins with both K-silicate and sericitic selvages were analyzed as well. Halite-saturated inclusions are dominated by Na, K, Fe, and in some inclusions Ca. Whereas these inclusions are significantly enriched in Ca, Mn, Fe, Zn, and Pb, fluids in all three veins contain significantly less Cu than early, high temperature, low-salinity inclusions.Analyses of all inclusion types show that whereas bulk-salinity of the hydrothermal fluid must be largely controlled by the magma, fluid–rock interactions have a significant role in controlling fluid compositions and metal ratios. Cu concentrations range over an order of magnitude, more than any other element, in all four samples containing low-salinity inclusions. We infer that variations are the result of fluid trapping after different amounts of fluid–rock reaction and chalcopyrite precipitation. Enrichment, relative to early fluids, of Mn, Pb, and Zn in fluids related to sericitic alteration is also likely the result of fluid–rock reaction, whereby these elements are released from biotite and feldspars as they alter to sericite. In halite-bearing inclusions, concentrations of Sr, Ca, Pb, and Ba are elevated in inclusions from the pyrite–quartz vein with sericitic alteration relative to halite-bearing inclusions from unaltered and potassically altered samples. Such enrichment is likely caused by the breakdown of plagioclase and K-feldspar in the alteration envelope, releasing Sr, Ca, Pb, and Ba.  相似文献   

Clutch, egg and body size variation among common eiders breeding in Hudson Bay, Canada     

Gregory J. Robertson  Austin Reed  H. Grant Gilchrist 《Polar research》2001,20(1):85-94

The Hudson Bay common eider ( Somateria molissima sedentaria ) is a unique subspecies of eider that remains within the confines of Hudson Bay throughout the year. We compared clutch, egg and body size variation among populations of common eiders breeding in eastern and western Hudson Bay. Clutch size did not differ substantially among these populations. All eiders in Hudson Bay laid larger clutches than other subspecies in eastern North America. As Hudson Bay common eiders do not undergo extensive migrations, they may have more energy reserves available to them for egg production. Eiders nesting in eastern Hudson Bay laid larger eggs than eiders nesting in western Hudson Bay. Further, eiders in eastern Hudson Bay tended to be structurally larger, but had smaller bill processes. These differences may have a genetic basis. Smaller egg size and body size may arise in western Hudson Bay from mixing with the smaller borealis subspecies nesting to the north. Further work to resolve genetic affinities, determine levels of male and female dispersal, and examine variation in reproductive ecology are needed to resolve the sources of these differences.  相似文献   

Comments on “The evolution of illite to muscovite: mineralogical and isotopic data from the Glarus Alps,Switzerland”     

J. Reed Glasmann 《Contributions to Mineralogy and Petrology》1987,96(1):72-74

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Calculation of pH and mineral equilibria in hydrothermal waters with application to geothermometry and studies of boiling and dilution   总被引：1，自引：0，他引：1  

Mark Reed  Nicolas Spycher 《Geochimica et cosmochimica acta》1984,48(7):1479-1492

Using chemical analyses and 25° pH measurements of quenched high-temperature waters, we calculate in situ pH and distribution of aqueous species at high temperature. This is accomplished by solving simultaneous mass action equations for complexes and redox equilibria and mass balance equations, on all components, including a H⁺ equation with as many as 60 terms (depending on water composition). This calculation provides accurate values for the activities of aqueous ions in a given water at high temperature, which are used to calculate an ion activity product (Q) for each of more than 100 minerals. The value of log(Q/K) for each mineral, where K is the equilibrium constant, provides a measure of proximity of the aqueous solution to equilibrium with the mineral. By plotting log Q/Kvs. T for natural waters, it is possible to determine: a) whether the water was in equilibrium with a host rock mineral assemblage, b) probable minerals in the equilibrium assemblage and c) the temperature of equilibrium. In cases where the fluid departs from equilibrium with a host rock assemblage, it is possible to determine whether this may result from boiling or dilution, and an estimate of amount of lost gas or diluting water can be determined.The calculation is illustrated by application to geothermal waters from Iceland, Broadlands, and Sulphur Bank, hot spring waters from Jemez, Yellowstone and Blackfoot Reservoir (Idaho) and fluid inclusions from the Sunnyside Mine, Colorado. It is shown that most geothermal waters approach equilibrium with a subsurface mineral assemblage at a temperature close to measured temperatures and that some hot springs also approach equilibrium with the host rock at temperatures above outlet temperatures but commonly below the Na-K-Ca temperatures. The log Q/K plots show that some discrepancies between Na-K-Ca temperatures on spring waters and actual temperatures result from a failure of alkali feldspars to equilibrate with the fluid and with each other.Calculations on Sulphur Bank fluids show that boiling probably caused cinnabar precipitation near 150°C and that the boiled fluids equilibrated with secondary minerals near 150° even though temperatures up to 185° have been measured at depth. For the fluid inclusions, the measured bubble temperatures are close to those calculated for equilibration of the fluid with the observed sulfide mineral assemblage.New estimates of stability constants for aluminum hydroxide complexes are included at the end of the paper.  相似文献   

Speleology and magnetobiostratigraphic chronology of the Buffalo Cave fossil site, Makapansgat, South Africa     

Andy I.R. Herries  Kaye E. Reed 《Quaternary Research》2006,66(2):233-245

Speleological, stratigraphic, paleomagnetic and faunal data is presented for the Buffalo Cave fossil site in the Limpopo Province of South Africa. Speleothems and clastic deposits were sampled for paleomagnetic and mineral magnetic analysis from the northern part of the site, where stratigraphic relationships could be more easily defined and a magnetostratigraphy could therefore be developed for the site. This is also where excavations recovered the fossil material described. A comparison of the east and South African first and last appearance data with the Buffalo Cave fauna was then used to constrain the magnetostratigraphy to produce a more secure age for the site. The magnetostratigraphy showed a change from normal to reversed polarity in the basal speleothems followed by a short normal polarity period in the base of the clastic deposits and a slow change to reversed directions for the remainder of the sequence. The biochronology suggested an optimal age range of between 1.0 Ma and 600,000 yr based on faunal correlation with eastern and southern Africa. A comparison of the magnetobiostratigraphy with the GPTS suggests that the sequence covers the time period from the Olduvai event between 1.95 and 1.78 Ma, through the Jaramillo event at 1.07 Ma to 990,000 yr, until the Bruhnes-Matuyama boundary at 780,000 yr. The faunal-bearing clastic deposits are thus dated between 1.07 Ma and 780,000 yr with the main faunal remains occurring in sediments dated to just after the end of the Jaramillo Event at 990,000 yr.  相似文献   

Parallelization strategies for rapid and robust evolutionary multiobjective optimization in water resources applications     

Y. Tang  P.M. Reed  J.B. Kollat 《Advances in water resources》2007

This study uses a formal metrics-based framework to demonstrate the Master–Slave (MS) and the Multiple-Population (MP) parallelization schemes for the Epsilon-Nondominated Sorted Genetic Algorithm-II (ε-NSGAII). The MS and MP versions of the ε-NSGAII generalize the algorithm’s auto-adaptive population sizing, ε-dominance archiving, and time continuation to a distributed processor environment using the Message Passing Interface. This study uses three test cases to compare the MS and MP versions of the ε-NSGAII: (1) an extremely difficult benchmark test function termed DTLZ6 drawn from the computer science literature, (2) an unconstrained, continuous hydrologic model calibration test case for the Leaf River near Collins, Mississippi, and (3) a discrete, constrained four-objective long-term groundwater monitoring (LTM) application. The MP version of the ε-NSGAII is more effective than the MS scheme when solving DTLZ6. Both the Leaf River and the LTM test cases proved to be more appropriately suited to the MS version of the ε-NSGAII. Overall, the MS version of the ε-NSGAII exhibits superior performance on both of the water resources applications, especially when considering its simplicity and ease-of-implementation relative to the MP scheme. A key conclusion of this study is that a simple MS parallelization strategy can exploit time-continuation and parallel speedups to dramatically improve the efficiency and reliability of evolutionary multiobjective algorithms in water resources applications.  相似文献   

DETERMINATION OF Ni,Ga, AND Ge IN IRON METEORITES BY X-RAY FLUORESCENCE ANALYSIS     

S. J. B. Reed 《Meteoritics & planetary science》1972,7(3):257-262

Although neutron activation analysis for trace Ga and Ge is more sensitive and possibly more accurate, X-ray fluorescence analysis is quicker, uses readily available equipment, and is non-destructive. It is shown that Ga, Ge, and Ni can be determined by X-ray fluorescence on metallographic polished mounts sufficiently accurately for classification according to Wasson's chemical groups. Results are given for 45 irons, including some not previously classified  相似文献   

Quaternary climate change and Heinrich events in the southern Balkans: Lake Prespa diatom palaeolimnology from the last interglacial to present   总被引：1，自引：0，他引：1  

Aleksandra Cvetkoska  Zlatko Levkov  Jane M. Reed  Bernd Wagner  Konstantinos Panagiotopoulos  Melanie J. Leng  Jack H. Lacey 《Journal of Paleolimnology》2015,53(2):215-231

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