Crustal contaminants in the Permian Oslo Rift, South Norway: constraints from Precambrian geochemistry     

Tom Andersen  Trine-Lise Knudsen 《Lithos》2000,53(3-4):247-264

During the late Paleozoic Oslo rifting event, the SW part of the Baltic Shield was penetrated by mantle-derived magmas from a depleted lithospheric or sublithospheric source. Along the way to their final emplacement, these magmas may have interacted with a heterogeneous continental crust, consisting of a mosaic of continental terranes, each with its unique composition and internal crustal history. Information on radiogenic isotope ratios and trace element distributions in the Precambrian terranes surrounding the rift can be used to define characteristic crustal components. These components may be used as endmembers in petrogenetic modelling of the Oslo Rift magmatic system. Based on available data, six endmember components can be identified, and (semi) quantitatively characterized in terms of Sr, Nd and Pb isotopes and selected trace elements. Data on the distribution of rock-types along the rift flanks allow estimates to be made of the relative importance of the components in different parts of the rift. Combining these data with petrological information may allow a realistic understanding of crust–magma interaction in the Oslo Rift magmatic system.  相似文献   

The limb effect of the Ki resonance line, 769.9 n m     

B. N. Andersen  S. Barth  V. Hansteen  T. Leifsen  P. B. Lilje  F. Vikanes 《Solar physics》1985,99(1-2):17-20

Low-noise observations have been obtained to search for a possible limb effect in the K i 769.9 nm resonance line. The observations were carried out along the north/south diameter of the solar disc. The data were individually corrected for the effects of straylight on the velocity measurements. A small, but significant limb effect is detected. The total shift in the line core from center to limb corresponds to 125 m s^–1 with an uncertainty of < 30 m s^–1.  相似文献   

IAG Newsletter     

Ole Baltazar Andersen 《Journal of Geodesy》2001,75(5-6):337-342

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Palaeomagnetic dating of fault rocks: evidence for Permian and Mesozoic movements and brittle deformation along the extensional Dalsfjord Fault, western Norway     

T. H. Torsvik  B. A. Sturt  E. Swensson  T. B. Andersen  J. F. Dewey 《Geophysical Journal International》1992,109(3):565-580

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Fluid and silicate glass inclusions in ultramafic and mafic xenoliths from Hierro,Canary Islands: implications for mantle metasomatism   总被引：4，自引：1，他引：4  

Thor H. Hansteen  Tom Andersen  Else-Ragnhild Neumann  Hielke Jelsma 《Contributions to Mineralogy and Petrology》1991,107(2):242-254

Fluid and solid inclusions have been studied in selected samples from a series of spinel-bearing Crdiopside-and Al-augite-series ultramafic (harzburgites, lherzolites, and olivine-clinopyroxene-rich rocks), and gabbroic xenoliths from Hierro, Canary Islands. In these samples several generations of fluid inclusions and ultramafic-and mafic-glass inclusions may be texturally related to different stages of crystal growth. The fluid inclusions consist of pure, or almost pure, CO₂. The solid inclusions in the ultramafic xenoliths comprise early inclusions of devitrified ultramafic glass, sulphide inclusions, as well as polyphase inclusions (spinel+clinopyroxene±glass±other silicates) believed to have formed from trapped basaltic melts. Vitreous basaltic glass±CO₂±sulphide±silicates are common as secondary inclusions in the ultramafic xenoliths, and as primary inclusions in the gabbroic xenoliths. Microthermometry gives minimum trapping temperatures of 1110° C for the early ultramafic-and mafic-glass inclusions, and a maximum of 1260–1280° C for late inclusions of host basaltic glass. In most samples the CO₂ inclusions show a wide range in homogenization temperatures (-40 to +31° C) as a result of decrepitation during ascent. The lowest homogenization temperatures of about-40° C, recorded in some of the smallest CO₂ inclusions, indicate a minimum depth of origin of 35 km (12 kbar) for both the Cr-diopside-and Al-augite-series xenoliths. The gabbroic xenoliths originate from a former magma chamber at a depth of 6–12 km.Contribution no. 100 of the Norwegian programme of the International Lithosphere Project  相似文献   

Recovery of Danish Coastal Ecosystems After Reductions in Nutrient Loading: A Holistic Ecosystem Approach     

Bo Riemann  Jacob Carstensen  Karsten Dahl  Henrik Fossing  Jens W. Hansen  Hans H. Jakobsen  Alf B. Josefson  Dorte Krause-Jensen  Stiig Markager  Peter A. Stæhr  Karen Timmermann  Jørgen Windolf  Jesper H. Andersen 《Estuaries and Coasts》2016,39(1):82-97

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Changes in monsoon-driven upwelling in the South China Sea over glacial Terminations I and II: a multi-proxy record     

Henrik Sadatzki  Michael Sarnthein  Nils Andersen 《International Journal of Earth Sciences》2016,105(4):1273-1285

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Bayesian estimation of reservoir properties—effects of uncertainty quantification of 4D seismic data     

Kjersti Solberg Eikrem  Geir Nævdal  Morten Jakobsen  Yan Chen 《Computational Geosciences》2016,20(6):1211-1229

This paper shows a history matching workflow with both production and 4D seismic data where the uncertainty of seismic data for history matching comes from Bayesian seismic waveform inversion. We use a synthetic model and perform two seismic surveys, one before start of production and the second after 1 year of production. From the first seismic survey, we estimate the contrast in slowness squared (with uncertainty) and use this estimate to generate an initial estimate of porosity and permeability fields. This ensemble is then updated using the second seismic survey (after inversion to contrasts) and production data with an iterative ensemble smoother. The impact on history matching results from using different uncertainty estimates for the seismic data is investigated. From the Bayesian seismic inversion, we get a covariance matrix for the uncertainty and we compare using the full covariance matrix with using only the diagonal. We also compare with using a simplified uncertainty estimate that does not come from the seismic inversion. The results indicate that it is important not to underestimate the noise in seismic data and that having information about the correlation in the error in seismic data can in some cases improve the results.  相似文献   

Fully-implicit simulation of vertical-equilibrium models with hysteresis and capillary fringe     

Halvor Møll Nilsen  Knut-Andreas Lie  Odd Andersen 《Computational Geosciences》2016,20(1):49-67

Geological carbon storage represents a new and substantial challenge for the subsurface geosciences. To increase understanding and make good engineering decisions, containment processes and large-scale storage operations must be simulated in a thousand year perspective. A hierarchy of models of increasing computational complexity for analysis and simulation of large-scale CO₂ storage has been implemented as a separate module of the open-source Matlab Reservoir Simulation Toolbox (MRST). This paper describes a general family of two-scale models available in this module. The models consist of two-dimensional flow equations formulated in terms of effective quantities obtained from hydrostatic reconstructions of vertical pressure and saturation distributions. The corresponding formulation is fully implicit and is the first to give a mass-conservative treatment and include general (non-linearized) CO₂ properties. In particular, the models account for compressibility, dissolution, and hysteresis effects in the fine-scale capillary and relative permeability functions and can be used to accurately and efficiently study the combined large-scale and long-term effects of structural, residual, and solubility trapping.  相似文献   

Lifetimes of some excited states in the rare earths: La ii,Ce ii,Pr ii,Nd ii,Sm ii,Yb i,Yb ii,and Lu ii     

T. Andersen  O. Poulsen  P. S. Ramanujam  A. Petrakiev Petkov 《Solar physics》1975,44(2):257-267

Radiative lifetimes for excited states in La ii, Ce ii, Pr ii, Nd ii, Sm ii, Yb i, Yb ii, and Lu ii have been determined by means of the beam-foil technique or the zero-field level-crossing method. The lifetimes for La, Ce, Pr, Nd, Sm, and Yb are shorter than those computed by summing the transition probabilities of Corliss and Bozman by a factor of up to ~5. The large discrepancies between the abundance of La, Ce, Pr, Nd, and Sm in the solar photosphere and in meteorites are eliminated or greatly reduced if the abundance determinations of the solar photosphere are based upon the gf values of Corliss and Bozman, corrected for by the present lifetimes.  相似文献