Aluminous granulites from the Pulur complex, NE Turkey: a case of partial melting, efficient melt extraction and crystallisation     

Gültekin Topuz  Rainer Altherr  Angelika Kalt  Muharrem Sat&#x;r  Olaf Werner  Winfried H. Schwarz 《Lithos》2004,72(3-4):183-207

In the Pulur complex, NE Turkey, a heterogeneous rock sequence ranging from quartz-rich mesocratic gneisses to silica- and alkali-deficient, Fe-, Mg- and Al-rich melanocratic rocks is characterized by granulite-facies assemblages involving garnet, cordierite, sillimanite, ilmenite, ±spinel, ±plagioclase, ±quartz, ±biotite, ±corundum, rutile and monazite. Textural evidence for partial melting in the aluminous granulites, particularly leucosomes, is largely absent or strongly obliterated by a late-stage hydrothermal overprint. However, inclusion relations, high peak P–T conditions, the refractory modes, bulk and biotite compositions of the melanocratic rocks strongly support a model of partial melting. The melt was almost completely removed from the melanocratic rocks and crystallised within the adjacent mesocratic gneisses which are silica-rich, bear evidence of former feldspar and show a large range in major element concentrations as well as a negative correlation of most elements with SiO₂. Peak conditions are estimated to be ≥800 °C and 0.7–0.8 GPa. Subsequent near-isothermal decompression to 0.4–0.5 GPa at 800–730 °C is suggested by the formation of cordierite coronas and cordierite–spinel symplectites around garnet and in the matrix. Sm–Nd, Rb–Sr and ⁴⁰Ar/³⁹Ar isotope data indicate peak conditions at 330 Ma and cooling below 300 °C at 310 Ma.  相似文献   

Efficient Computation of Linearized Cross-Covariance and Auto-Covariance Matrices of Interdependent Quantities   总被引：2，自引：0，他引：2  

Wolfgang Nowak  Sascha Tenkleve  Olaf A. Cirpka 《Mathematical Geology》2003,35(1):53-66

In many geostatistical applications, spatially discretized unknowns are conditioned on observations that depend on the unknowns in a form that can be linearized. Conditioning takes several matrix–matrix multiplications to compute the cross-covariance matrix of the unknowns and the observations and the auto-covariance matrix of the observations. For large numbers n of discrete values of the unknown, the storage and computational costs for evaluating these matrices, proportional to n ², become strictly inhibiting. In this paper, we summarize and extend a collection of highly efficient spectral methods to compute these matrices, based on circulant embedding and the fast Fourier transform (FFT). These methods are applicable whenever the unknowns are a stationary random variable discretized on a regular equispaced grid, imposing an exploitable structure onto the auto-covariance matrix of the unknowns. Computational costs are reduced from O(n ²) to O(nlog₂ n) and storage requirements are reduced from O(n ²) to O(n).  相似文献   

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sediments from Hong Kong     

Jochen F. Müller  Caroline Gaus  Joelle A. Prange  Olaf Ppke  Ka Fai Poon  M. H. W. Lam  Paul K. S. Lam 《Marine pollution bulletin》2002,45(1-12)

Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in 14 sediment samples collected from four sites in the Mai Po Marshes Nature Reserve (within a RAMSAR Site) and from another six sites in Victoria Harbour and along the Hong Kong coastline. Elevated levels of PCDDs, and particularly OCDD, were detectable in all samples collected from the Mai Po Marshes and five of the six sites. In contrast to PCDDs, PCDFs were mainly found in sediment samples collected from industrial areas (Kwun Tong and To Kwa Wan) in Victoria Harbour. PCDD/F levels and congener profiles in the samples from the Mai Po Marshes Nature Reserve in particular show strong similarities to those reported in studies which have attributed similar elevated PCDD concentrations to nonanthropogenic PCDD sources.  相似文献   

Verwitterungsversuche mit organischen Säuren an einigen schwerlöslichen Fe-Pb-Zn und Cu Erzmineralen,angewendet auf die Genese des Kupferschiefers     

Olaf Brockamp 《Contributions to Mineralogy and Petrology》1974,43(3):213-221

The 1–2 mm fraction of FeS₂, Fe₃O₄, PbS, PbSO₄, ZnS, ZnCO₃, Cu₂S and Cu₂(OH)₂CO₃ was dissolved in water, dilute HCl and 0.01 m organic acids (tannin, salicylic acid and citric acid) at 1 atm and 20° C. Duplicate samples of one gram each were placed in 50 ml of solvent with shaking once each day for one month at pH's of 2, 4 and 6. The pH of all the solutions was maintained by periodic addition of either HCl or NaOH. Comparing the results at pH 6, a value observed under surface conditions, the organic acids had a higher metal ion concentration because of their complexing ability. Results at pH 6 in ppm of the metal ions are shown below: For example the Fe concentration dissolved from pyrite in water was 0.02 ppm but 2.3–4.3 in the organic acids. From malachite 0.2 ppm Cu were dissolved by water but 25–1550 ppm by the organic acids. In general Cu minerals seem to be more soluble in organic acids than the Pb, Zn and Fe minerals. The different solution power of the organic acids within the experiments seems not to be caused by the crystallography of the minerals tested. Further there apparently is no preferential complexing of an organic acid with respect to a distinct anion or cation of the minerals. The experiments therefore show, that it is difficult to predict exactly which organic acid is most effective in dissolving minerals. However the experiments should apply to natural weathering conditions of ore minerals and may aid in understanding metal ion transport. For example the origin of the high Cu concentration in the sedimentary “Kupferschiefer” are more easily explained by weathering and transport of Cu in the form of organo-metallic complexes than by reaction with only water. The Cu content in organic acids is much higher than in water and the Cu concentration in the solutions now is not so strongly controlled by the solubility of Cu-cabonates and phosphates.  相似文献   

The geology of parts of Southern Norway     

Olaf Holtedahl  Arne Bugge  Carl Fred. Kolderup  Halvor Rosendahl  Jakob Schetelig  Leif Størmer 《Proceedings of the Geologists' Association. Geologists' Association》1934,45(3):307-IN8

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Waldemar Christopher Brögger in memoriam     

Olaf Holtedahl 《International Journal of Earth Sciences》1940,31(3-4):297-299

Ohne Zusammenfassung  相似文献   

Three-dimensional geostatistical inversion of flowmeter and pumping test data   总被引：1，自引：0，他引：1  

Li W  Englert A  Cirpka OA  Vereecken H 《Ground water》2008,46(2):193-201

We jointly invert field data of flowmeter and multiple pumping tests in fully screened wells to estimate hydraulic conductivity using a geostatistical method. We use the steady-state drawdowns of pumping tests and the discharge profiles of flowmeter tests as our data in the inference. The discharge profiles need not be converted to absolute hydraulic conductivities. Consequently, we do not need measurements of depth-averaged hydraulic conductivity at well locations. The flowmeter profiles contain information about relative vertical distributions of hydraulic conductivity, while drawdown measurements of pumping tests provide information about horizontal fluctuation of the depth-averaged hydraulic conductivity. We apply the method to data obtained at the Krauthausen test site of the Forschungszentrum Jülich, Germany. The resulting estimate of our joint three-dimensional (3D) geostatistical inversion shows an improved 3D structure in comparison to the inversion of pumping test data only.  相似文献   

A Dynamic Model to Simulate Arsenic,Lead, and Mercury Contamination in the Terrestrial Environment During Extreme Floods of Rivers     

Marcus Schulz  Olaf Büttner  Martina Baborowski  Michael Böhme  Michael Matthies  Wolf von Tümpling 《洁净——土壤、空气、水》2009,37(3):209-217

Beside damages of infrastructure in industrial regions, extreme floods can cause contamination with particle‐bound pollutants, e. g., due to erosion of soils and sediments. In order to predict contamination with inorganic pollutants, the transport and fate of arsenic, lead, and mercury during a fictive flood event of River Vereinigte Mulde in the region of Bitterfeld (Germany) with 200 years recurrence time was modeled. The finite element model system Telemac2D, which is subdivided into a hydrodynamic (Telemac‐2D), a transport (Subief‐2D), and a water quality module (wq2subief) was applied. The transport and water quality model models were calibrated using results of sediment trap exposures in the floodplain of River Vereinigte Mulde. Model results exhibited that the spatial patterns of particle‐associated arsenic and lead concentrations significantly changed. Extended, mostly agriculturally used areas showed arsenic and lead concentrations between 150 and 200 mg kg^–1 and 250 and 300 mg kg^–1, respectively, while urban areas were to a great extent spared from high contamination with arsenic and lead. Concentrations of particle‐associated mercury showed a pattern distinct from those of arsenic and lead. Outside of small patches with concentrations up to 63 mg kg^–1, concentrations of particle‐associated mercury remained close to zero. Differences in the spatial patterns of the three pollutants regarded mainly arise from significantly different initial and boundary conditions. Sensitivity analyses of initial and boundary conditions revealed a high sensitivity of particle‐bound pollutant concentrations, whereas the sensitivities of concentrations of suspended sediments and soluble pollutants were mediocre to negligible.  相似文献   

A Dynamic Model to Simulate Spills of Fuel and Diesel Oil in the Terrestrial Environment during Extreme Fluvial Floods     

Marcus Schulz  Olaf Büttner  Michael Böhme  Michael Matthies  Wolf von Tümpling 《洁净——土壤、空气、水》2009,37(9):735-741

Extreme fluvial floods may cause severe contamination with fuel oil and diesel, originating from gasoline pipes and tanks in private households and industrial areas, respectively. Geo‐referenced oil spills in the region of Bitterfeld (Germany) after extreme flood events, such as in August 2002, were simulated using the two‐dimensional (2D) Finite Element model system Telemac2D, which is subdivided into a hydrodynamic (Telemac‐2D) and a transport module (Subief2D). Fuel oil settled via adhesion showed a thickness of less than 1.0 mm. Fuel oil concentrations on the flood wave amounted up to 80 g m^–3 in the vicinity of the point sources. At a distance of several hundred meters downstream of the point sources, the fuel oil concentrations were calculated to be zero. Settled areas were only partially contaminated with fuel oil. While one village experienced severe oil contamination, the town of Bitterfeld was almost unaffected by oil spills. It was demonstrated that the 2D transport model applied is capable of simulating fuel oil spills during extreme high waters in the terrestrial environment. Such simulations of fuel oil spills will feed into a GIS‐based decision support system of flood protection.  相似文献   

Impact of Biomass-Decay Terms on the Simulation of Pulsed Bioremediation     

Olaf A. Cirpka  Peter K. Kitanidis 《Ground water》2000,38(2):254-263

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