Zur Schwefelisotopenzusammensetzung der Pb-Zn-Vererzung des Grazer Paläozoikums (Ostalpen)     

E. Pak  E. Schroll  L. Weber 《Mineralium Deposita》1980,15(3):315-325

Zusammenfassung Die Schwefelisotopenzusammensetzung von sulfidischen Erzmineralen und Baryten der unterdevonischen schichtgebundenen Bleiglanz-Zinkblende-Baryt-Erzvorkommen des Grazer Paläozoikums (Ostalpen, Österreich) wurde untersucht. Zur Analyse gelangten 64 Proben von etwa 15 Lokalitäten. Die Schwefelisotopenverteilung zeigt Ähnlichkeiten mit anderen an das Devon gebundenen schwerspatführenden Lagerstätten. Die Baryte ergaben ³⁴S-Werte von +23, 1 bis +27, 8, die dem Meerwassersulfat devonischen Alters entsprechen. Die untersuchten Galenite variieren von +2, 4 bis +6, 9 und die Sphalerite von +3, 3 bis +9, 1. Die Werte der Pyrite zeigen einen großen Streubereich (–27, 4 bis +37, 6). Eine massive buntmetallarme Pyritvererzung fällt durch sehr schweren Schwefel auf. Späte Mineralisationsphasen der Sulfide tendieren gleichfalls zur Anreicherung des schweren Schwefels.

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The sulphur isotope compositions of 64 samples of sulphide minerals and barites from the strata-bound Lower Devonian ore deposits of the Paleozoic Complex of Graz in the Eastern Alps (Austria) have been investigated. The ³⁴S-values of galenites and sphalerites show only small variations in the range of +2, 4 up to +6, 9 for PbS and +3, 3 up to +9, 1 for ZnS indicating abiogenic origin. Later remobilized sulphide minerals show a tendency to heavier sulphur. The deposition of pyrites is influenced partly by bacteriogenic processes (–27, 4 up to +37, 6). The enrichment of heavier sulphur characterizes massive pyrite mineralisations being poor on base metals. The sulphur isotope compositions of barites (+23, 1 up to 27, 8) correspond to Devonian sea water sulphate. An ore free barite characterized by increased strontium concentration shows heavier sulphur (+29, 6) than barites from ore beds.

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Derzeit Oberste Bergbehörde, Bundesministerium für Handel, Gewerbe und Industrie (Wien)  相似文献   

Frequency Changes of Weather Types in the Alpine Region since 1945     

G. Stefanicki  P. Talkner  R. O. Weber 《Theoretical and Applied Climatology》1998,60(1-4):47-61

Summary The annual occurrence of different weather types of Schüepp’s synoptic classification in the Alpine region has significantly changed since the beginning of its recording in 1945. The annual frequency (number of days per year) has shifted towards more convective and less advective weather types. Since 1945 the number of long-lasting convective episodes rose and the number of long-lasting advective episodes lessened. Most of these changes took place in winter. The annual frequencies of weather types and the annual mean of certain local meteorological parameters are significantly correlated. On the large scale there is a strong interdependence between the high pressure weather type and the North Atlantic Oscillation (NAO) index which is based on the sea-level pressure difference between Portugal and Iceland. Received July 28, 1997 Revised November 18, 1997  相似文献   

Geochronology: Radiometric dating of rocks and minerals: Christopher T. Harper (Editor), 1973. Benchmark Papers in Geology. Dowden, Hutchinson and Ross, Stroudsburg, Pa., xv + 469 pp., £ 12.00     

Jon N. Weber 《Earth》1974,10(4):349

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Cosmochemical and spectroscopic properties of Northwest Africa 7325—A consortium study          下载免费PDF全文

I. Weber  A. Morlok  A. Bischoff  H. Hiesinger  D. Ward  K. H. Joy  S. A. Crowther  N. D. Jastrzebski  J. D. Gilmour  P. L. Clay  R. A. Wogelius  R. C. Greenwood  I. A. Franchi  C. Münker 《Meteoritics & planetary science》2016,51(1):3-30

This work is part of a project to build an infrared database in order to link IR data of planetary materials (and therefore possible Mercury material) with remote sensing observations of Mercury, which will probably be obtained by the MERTIS instrument on the forthcoming BepiColombo mission. The unique achondrite Northwest Africa (NWA) 7325, which has previously been suggested to represent the first sample from Mercury, was investigated by optical and electron microscopy, and infrared and Raman spectroscopy. In addition, the oxygen, strontium, xenon, and argon isotopes were measured and the abundance of selected trace elements determined. The meteorite is a cumulate rock with subchondritic abundances of HFSE and REE and elevated Sr contents, which underwent a second heating and partial remelting process. Oxygen isotope measurements show that NWA 7325 plots in the ureilite field, close to the ALM‐A trachyandesitic fragment found in the unique Almahata Sitta meteorite breccia. On the other hand, mineralogical investigations of the pyroxenes in NWA 7325 provide evidence for similarities to the lodranites and acapulcoites. Furthermore, the rock is weakly shocked and argon isotope data record ancient (~4.5 Ga) plateau ages that have not been reset. The sample records a cosmogenic exposure age of ~19 Ma. Systematics of Rb‐Sr indicate an extreme early volatile depletion of the precursor material, similar to many other achondrite groups. However, despite its compositional similarities to other meteorite groups, our results suggest that this meteorite is unique and unrelated to any other known achondrite group. An origin for NWA 7325 as a sample from the planet Mercury is not supported by the results of our investigation. In particular, the evidence from infrared spectroscopy indicates that a direct relationship between NWA 7325 and the planet Mercury can be ruled out: no acceptable spectral match between laboratory analyses and remote sensing observations from Mercury has been obtained. However, we demonstrate that infrared spectroscopy is a rapid and nondestructive method to characterize mineral phases and thus an excellent tool for planetary surface characterization in space missions.  相似文献   

Border Tax adjustment – legal perspective     

Rolf H. Weber 《Climatic change》2015,133(3):407-417

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Solar Spectral Irradiance Variations in 240 – 1600 nm During the Recent Solar Cycles 21 – 23     

J.?PagaranEmail author  M.?Weber  M.?T.?DeLand  L.?E.?Floyd  J.?P.?Burrows 《Solar physics》2011,272(1):159-188

Regular solar spectral irradiance (SSI) observations from space that simultaneously cover the UV, visible (vis), and the near-IR (NIR) spectral region began with SCIAMACHY aboard ENVISAT in August 2002. Up to now, these direct observations cover less than a decade. In order for these SSI measurements to be useful in assessing the role of the Sun in climate change, records covering more than an eleven-year solar cycle are required. By using our recently developed empirical SCIA proxy model, we reconstruct daily SSI values over several decades by using solar proxies scaled to short-term SCIAMACHY solar irradiance observations to describe decadal irradiance changes. These calculations are compared to existing solar data: the UV data from SUSIM/UARS, from the DeLand & Cebula satellite composite, and the SIP model (S2K+VUV2002); and UV-vis-IR data from the NRLSSI and SATIRE models, and SIM/SORCE measurements. The mean SSI of the latter models show good agreement (less than 5%) in the vis regions over three decades while larger disagreements (10 – 20%) are found in the UV and IR regions. Between minima and maxima of Solar Cycles 21, 22, and 23, the inferred SSI variability from the SCIA proxy is intermediate between SATIRE and NRLSSI in the UV. While the DeLand & Cebula composite provide the highest variability between solar minimum and maximum, the SIP/Solar2000 and NRLSSI models show minimum variability, which may be due to the use of a single proxy in the modeling of the irradiances. In the vis-IR spectral region, the SCIA proxy model reports lower values in the changes from solar maximum to minimum, which may be attributed to overestimations of the sunspot proxy used in modeling the SCIAMACHY irradiances. The fairly short timeseries of SIM/SORCE shows a steeper decreasing (increasing) trend in the UV (vis) than the other data during the descending phase of Solar Cycle 23. Though considered to be only provisional, the opposite trend seen in the visible SIM data challenges the validity of proxy-based linear extrapolation commonly used in reconstructing past irradiances.  相似文献   

The Value of Practice-Based Knowledge     

Edward P. Weber  Jill M. Belsky  Denise Lach  Antony S. Cheng 《社会与自然资源》2014,27(10):1074-1088

Increasing recognition of the value of practice-based or experiential knowledge in natural resource management justifies the creation of a new category of articles in Society & Natural Resources that we are calling Practice-Based Knowledge (PBK). The rationale for focusing on PBK is due to its key role in the emergence of hybrid governance institutions across state, market, and civil society, understanding the complexity of dynamic socioecological systems, recognizing the challenges of multiple knowledge systems and context-specific practices, embracing the power of informal institutions and civic science, and engaging debates on the growing prevalence of market-oriented conservation. The goal is to provide a dedicated space within the published, peer-reviewed literature for scholars, government officials, nonprofit managers, and engaged citizens to share experiences informed by practical action. Relevant and timely practice-based insights may improve understanding and management of social and ecological processes and systems, while also offering the potential to contribute to theory.  相似文献   

Data-driven Expansion of Dense Regions – A Cartographic Approach in Literary Geography     

Anne-Kathrin Weber Reuschel 《The Cartographic journal》2014,51(2):123-140

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Results of the DEKORP 1 (BELCORP-DEKORP) deep seismic reflection studies in the western part of the Rhenish Massif   总被引：1，自引：0，他引：1  

DEKORP Research GroupH.-J. Anderle  R. Bittner  R. Bortfeld  J. Bouckaert  G. Büchel  G. Dohr  H.-J. Dürbaum  H. Durst  W. Fielitz  E. Flüh  T. Gundlach  L. Hance  A. Henk  F. Jordan  D. Kläschen  M. Klöckner  R. Meissner  W. Meyer  O. Oncken  C. Reichert  K.-H. Ribbert  P. Sadowiak  H.-U. Schmincke  J. Schmoll  R. Walter  K. Weber  U. Weihrauch  Th. Wever 《Geophysical Journal International》1991,106(1):203-227

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Development of an improved empirical model for slant delays in the troposphere (GPT2w)   总被引：7，自引：0，他引：7  

Johannes Böhm  Gregor Möller  Michael Schindelegger  Gregory Pain  Robert Weber 《GPS Solutions》2015,19(3):433-441

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