Geochemical study on a well in the Western Canada Basin: relation of the aromatic distribution pattern to maturity of organic matter     

Matthias Radke  Dietrich H. Welte  Helmut Willsch 《Geochimica et cosmochimica acta》1982,46(1):1-10

Thirty-one rock samples from a Western Canada Basin well have been analysed for aromatics, using glass capillary gas chromatography with simultaneous flame ionization and sulfur-selective flame photometric detection. A uniform aromatic distribution pattern with a marked predominance of di- and tricyclic aromatic hydrocarbons was observed throughout a depth interval of 3000 meters comprising Cretaceous and Jurassic sediments. The very high relative abundance of sulfur aromatics at two narrow intervals in the Triassic and Mississippian is attributed to a major change in facies. Gradual changes with increasing depth have been observed for a series of compound ratios, which had been calculated from the isomers of methyl- and dimethylphenanthrene, and their parent compounds. These changes reflect the increasing thermal maturation of the sedimentary organic matter. A Methylphenanthrene Index (MPI) has been introduced, which exhibited a very good correlation with vitrinite reflectance data. The MPI is the first maturity parameter which is based on a series of aromatic hydrocarbons. This hydrocarbon internal maturity parameter permits the recognition and definition of maturity levels in extracts which can be compared to the maturity (e.g. vitrinite reflectance) of source rocks.  相似文献   

Quasi-static and Quasi-dynamic Modeling of Earthquake Failure at Intermediate Scales     

Gert Zöller  Matthias Holschneider  Yehuda Ben-Zion 《Pure and Applied Geophysics》2004,161(9-10):2103-2118

We present a model for earthquake failure at intermediate scales (space: 100 m–100 km, time: 100 m/v _shear- 1000’s of years). The model consists of a segmented strike–slip fault embedded in a 3-D elastic solid as in the framework of Ben-Zion and Rice (1993). The model dynamics is governed by realistic boundary conditions consisting of constant velocity motion of the regions around the fault, static/kinetic friction laws with possible gradual healing, and stress transfer based on the solution of Chinnery (1963) for static dislocations in an elastic half-space. As a new ingredient, we approximate the dynamic rupture on a continuous time scale using a finite stress propagation velocity (quasi–dynamic model) instead of instantaneous stress transfer (quasi–static model). We compare the quasi–dynamic model with the quasi–static version and its mean field approximation, and discuss the conditions for the occurrence of frequency-size statistics of the Gutenberg–Richter type, the characteristic earthquake type, and the possibility of a spontaneous mode switching from one distribution to the other. We find that the ability of the system to undergo a spontaneous mode switching depends on the range of stress transfer interaction, the cell size, and the level of strength heterogeneities. We also introduce time-dependent log (t) healing and show that the results can be interpreted in the phase diagram framework. To have a flexible computational environment, we have implemented the model in a modular C++ class library.  相似文献   

Multi-Element Isotope Dilution Sector Field ICP-MS: A Precise Technique for the Analysis of Geological Materials and its Application to Geological Reference Materials   总被引：1，自引：1，他引：1  

Matthias Willbold  Klaus Peter Jochum 《Geostandards and Geoanalytical Research》2005,29(1):63-82

We present a multi-element technique for the simultaneous determination of twelve trace elements in geological materials by combined isotope dilution (ID) sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) following simple sample digestion. In addition, the concentrations of fourteen other trace elements have been obtained using the ID determined elements as internal standards. This method combines the advantages of ID (high precision and accuracy) with those of SF-ICP-MS (multi-element capability, fast sample processing without element separation) and overcomes the most prevailing drawbacks of ICP-MS (matrix effects and drift in sensitivity). Trace element concentration data for BHVO-1 (n = 5) reproduced to within 1–3% RSD with an accuracy of 1–2% relative to respective literature values for ID values and 2–3% for all other values. We have applied this technique to the analysis of seventeen geological reference materials from the USGS, GSJ and IAG. The sample set also included the new USGS reference glasses BCR-2G, BHVO-2G and BIR-1G, as well as the MPI-DING reference glasses KL2-G and ML3B-G, and NIST SRM 612. Most data agreed within 3–4% with respective literature data. The concentration data for the USGS reference glasses agreed in most cases with respective data of the original rock powder within the combined standard uncertainty of the method (2–3%), except the U concentration of BIR-1G, which showed a three times higher concentration compared to BIR-1.  相似文献   

Late Miocene – Recent exhumation of the central Himalaya and recycling in the foreland basin assessed by apatite fission-track thermochronology of Siwalik sediments, Nepal     

Peter van der Beek  Xavier Robert  Jean-Louis Mugnier  Matthias Bernet  Pascale Huyghe  Erika Labrin 《Basin Research》2006,18(4):413-434

Thermochronological analysis of detrital sediments derived from the erosion of mountain belts and contained in the sedimentary basins surrounding them allows reconstructing the long-term exhumation history of the sediment source areas. The effective closure temperature of the thermochronological system analysed determines the spatial and temporal resolution of the analysis through the duration of the lag time between closure of the system during exhumation and its deposition in the sedimentary basin. Here, we report apatite fission-track (AFT) data from 31 detrital samples collected from Miocene to Pliocene stratigraphic sections of the Siwalik Group in western and central Nepal, as well as three samples from modern river sediments from the same area, that complement detrital zircon fission-track (ZFT) and U–Pb data from the same samples presented in a companion paper. Samples from the upper part of the stratigraphic sections are unreset and retain a signal of source-area exhumation; they show spatial variations in source-area exhumation rates that are not picked up by the higher-temperature systems. More deeply buried samples have been partially reset within the Siwalik basin and provide constraints on the thermal and kinematic history of the fold-and-thrust belt itself. The results suggest that peak source-area exhumation rates have been constant at ∼1.8 km Myr⁻¹ over the last ∼7 Ma in central Nepal, whereas they ranged between 1 and ∼1.5 km Myr⁻¹ in western Nepal over the same time interval; these spatial variations may be explained by either a tectonic or climatic control on exhumation rates, or possibly a combination of the two. Increasing lag times within the uppermost part of the sections suggest an increasing component of apatites that have been recycled within the Siwalik belt and are corroborated by AFT ages of modern river sediment downstream as well as the record of the distal Bengal Fan. The most deeply buried and most strongly annealed samples record onset of exhumation of the frontal Siwaliks along the Himalayan frontal thrust at ∼2 Ma and continuous shortening at rates comparable with the present-day shortening rates from at least 0.3 Ma onward.  相似文献   

The Greenland Ice Core Chronology 2005, 15–42 ka. Part 1: constructing the time scale     

Katrine K. Andersen  Anders Svensson  Sigfus J. Johnsen  Sune O. Rasmussen  Matthias Bigler  Regine Rthlisberger  Urs Ruth  Marie-Louise Siggaard-Andersen  Jrgen Peder Steffensen  Dorthe Dahl-Jensen  Bo M. Vinther  Henrik B. Clausen 《Quaternary Science Reviews》2006,25(23-24):3246

The Greenland Ice Core Chronology 2005, GICC05, is extended back to 42 ka b2k (before 2000 AD), i.e. to the end of Greenland Stadial 11. The chronology is based on independent multi-parameter counting of annual layers using comprehensive high-resolution measurements available from the North Greenland Ice Core Project, NGRIP. These are measurements of visual stratigraphy, conductivity of the solid ice, electrolytical melt water conductivity and the concentration of Na⁺, Ca²⁺, SO₄²⁻, NO₃⁻, NH₄⁺. An uncertainty estimate of the time scale is obtained from identification of ‘uncertain’ annual layers, which are counted as 0.5±0.5 years. The sum of the uncertain annual layers, the so-called maximum counting error of the presented chronology ranges from 4% in the warm interstadial periods to 7% in the cold stadials. The annual accumulation rates of the stadials and interstadials are on average one-third and half of the present day values, respectively, and the onset of the Greenland Interstadials 2, 3, and 8, based on 20 year averaged δ¹⁸O values, are determined as 23,340, 27,780, and 38,220 yr b2k in GICC05.  相似文献   

Area-Averaged Surface Fluxes Over the Litfass Region Based on Eddy-Covariance Measurements     

Frank Beyrich  Jens-Peter Leps  Matthias Mauder  Jens Bange  Thomas Foken  Sven Huneke  Horst Lohse  Andreas Lüdi  Wouter M. L. Meijninger  Dmitrii Mironov  Ulrich Weisensee  Peter Zittel 《Boundary-Layer Meteorology》2006,121(1):33-65

Micrometeorological measurements (including eddy-covariance measurements of the surface fluxes of sensible and latent heat) were performed during the LITFASS-2003 experiment at 13 field sites over different types of land use (forest, lake, grassland, various agricultural crops) in a 20 × 20 km² area around the Meteorological Observatory Lindenberg (MOL) of the German Meteorological Service (Deutscher Wetterdienst, DWD). Significant differences in the energy fluxes could be found between the major land surface types (forest, farmland, water), but also between the different agricultural crops (cereals, rape, maize). Flux ratios between the different surfaces changed during the course of the experiment as a result of increased water temperature of the lake, changing soil moisture, and of the vegetation development at the farmland sites. The measurements over grass performed at the boundary-layer field site Falkenberg of the MOL were shown to be quite representative for the farmland part of the area. Measurements from the 13 sites were composed into a time series of the area-averaged surface flux by taking into account the data quality of the single flux values from the different sites and the relative occurrence of each surface type in the area. Such composite fluxes could be determined for about 80% of the whole measurement time during the LITFASS-2003 experiment. Comparison of these aggregated surface fluxes with area-averaged fluxes from long-range scintillometer measurements and from airborne measurements showed good agreement.  相似文献   

New research on High Asia,Tibet and the Himalayas     

Matthias Kuhle Prof. Dr. 《GeoJournal》1986,12(3):341-343

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Experimental investigation of the kinetics of the reaction 1 tremolite+11 dolomite⇌8 forsterite+13 calcite+9 CO2+1 H2O     

Wilhelm Heinrich  Paul Metz  Matthias Gottschalk 《Contributions to Mineralogy and Petrology》1989,102(2):163-173

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Sediment pollution in the Vågen,Bergen harbour,Norway     

Matthias Paetzel  Geir Nes  Leif Leifsen  Hans Schrader 《Environmental Geology》2003,43(4):476-483

Recent sediments in the Vågen, Bergen harbour, are subjected to injection of untreated sewage from around 15,000 person equivalent. Here the distribution of trace elements is mapped in surface and subsurface sediments. Selected trace-element concentrations decrease from the inner towards the outer Vågen. These concentration gradients do not correlate with minerogenic grain size. Linear correlation, combined with enriched sediment trace elements, are used to infer sources for these elements and possible reasons for their enrichment. (1) Frequent use of dental amalgam might be related to the enrichments of and correlation between Ag, Cu, Hg and Sn in surficial sediments pre-1994. (2) Enrichment and correlation of Cu/Zn may be related to the commercial and private use of anti-fouling boat-paint. Further, tributyltin is suggested as a source of Sn enrichment. (3) Increased traffic in the city of Bergen with gasoline combustion and car-wheel wear-off release Pb and Zn. (4) Hg and Pb might have been atmospherically supplied due to the combustion of coal in a nearby gas plant pre-1985. (5) No correlation is observed between enriched Vågen trace metals and bedrock element composition of the surrounding mountains, indicating a minor supply from erosion.  相似文献   

Area-Averaged Sensible Heat Flux and a New Method to Determine Zero-Plane Displacement Length over an Urban Surface using Scintillometry     

Manabu Kanda  Ryo Moriwaki  Matthias Roth  Tim Oke 《Boundary-Layer Meteorology》2002,105(1):177-193

Field observations of area-averagedturbulence characteristics were conducted in a densely built-up residential neighbourhood in Tokyo, Japan. In addition to eddy-correlation (EC) sensors a scintillometer was used for the first time in a city. Significant results include: (1) Scintillometer-derived sensible heat fluxes, Q_H, obtained at a height 3.5 times the building height agree well with those using the EC technique; (2) source areas for the scintillometer fluxes are larger than for the EC sensors, so that at low heights over inhomogeneous terrain scintillometry offers advantages; (3) new similarity relationships for dissipation rates are proposed for urban areas; (4) a new technique that uses simultaneous scintillation measurements at two heights to directly estimate area-averaged zero-plane displacement height, z_d, is proposed. z_d estimated in this way depends slightly on atmospheric stability (lower z_d under more unstable conditions).  相似文献