scholarly journals Geological aspects of the Danish North Sea sector. With a report on the wells Dansk Nordsø E-1, E-2, F-1, G-1, H-1, I-1, J-1 and K-1

1978 ◽  
Vol 44 ◽  
pp. 1-85
Author(s):  
Leif Banke Rasmussen
Keyword(s):  
North Sea ◽  
Cross Sections

This paper presents lithological and chronostratigraphical descriptions of geological sections from the following eight Danish North Sea wells: Dansk Nordsø E-1, E-2, F-1, G-1, H-1, 1-1, J-1, and K-1, in which deposits of Triassic, Jurassic, Cretaceous, Tertiary and Quaternary age were found. The chronostratigraphy of the well sections is mainly a result of micropalaeontological examination of samples.The paper gives additional comments on the structural conditions of the Danish North Sea sector with reference to an outline map, and to a number of cross sections through the southern part of the Danish portion of the Central Graben. Some regional structures are given new names.

scholarly journals STABILITY OF TIDAL CHANNELS DEPENDENT ON RIVER IMPROVEMENT

1976 ◽  
Vol 1 (15) ◽  
pp. 102 ◽  
Author(s):  
Volker Barthel
Keyword(s):  
North Sea ◽  
Cross Sections ◽  
Main Channel ◽  
Tidal Channels ◽  
Weser Estuary ◽  
The North ◽  
Investigation Area ◽  
German Coast ◽  
Improvement Measures ◽  
The North Sea

Many authors have dealt with the migration of sand in front of the German coast of the North Sea. Especially the movement of sand-banks and deep channels in the Weser-estuary was subject matter of several investigations with different results. Thorough investigations of selected cross-sections point out, that the movement goes on in some regions. The important shipping channel however has obtained a certain stability during the last 3o - 4o years, because the migration of sand occurs otherwise than in former days. This phenomenon coincides with the extensive and decisive river improvement measures in the inner part of the Weser-estuary. Current measurements in the investigation area demonstrate, that concentrated tidal currents in the deep channels guarantee a sufficient clearance for shipping purpose. It seems to be sure, that for the present no essential shifting of the main channel calls for important measures in the field of shipping, dredging and building of sea-marks.

Glaciotectonics and tunnel valleys in the southeastern North Sea imaged by high-resolution multi-channel seismics

2020 ◽  
Author(s):  
Arne Lohrberg ◽  
Sebastian Krastel ◽  
Daniel Unverricht ◽  
Klaus Schwarzer
Keyword(s):  
High Resolution ◽  
North Sea ◽  
Cross Sections ◽  
Forward Direction ◽  
Subsequent Formation ◽  
Reflection Seismic ◽  
Dense Grid ◽  
Thrust Sheets ◽  
Multiple Deformation ◽  
East West

<p>Glaciotectonic disturbance of sediments and tunnel valleys are often found near the margin of former ice sheets. Hence, these landforms can be used to reconstruct the dynamics of former ice sheet margins. The direction of thrusts usually points perpendicular to the ice front. Considering heterogeneity due to local ice advances, this relation can be used to infer the regional forward direction of large ice lobes. Here, we present a dense grid of high-resolution 2D multi-channel reflection seismic data from the German sector of the southeastern North Sea imaging a buried glaciotectonic complex and tunnel valleys in unprecedented detail.</p><p>We have identified individual thrust sheets in an area of approx. 650 km² (combined with recent results of Winsemann et al. (2020)). All thrust sheets are buried and partly eroded at their top. Two major phases of thrusting with two corresponding detachment surfaces have been identified in the subsurface, of which the younger phase led to the deformation of sediments several kilometers further into the foreland. The thickness of individual thrust sheets differs between 180 and 240 m. Some thrust sheets have been cut by the subsequent formation of tunnel valleys with an overall incision direction ranging from east-west to northeast-southwest. The glaciotectonic complex is limited to its southeast by an updipping reflector, which represents the margin of a source depression.</p><p>The restauration of cross-sections shows that the thrust sheets transported sediments over more than a kilometer towards the northwest to west, which relates the formation of the thrust sheets and the source depression. The landforms are very similar to a hill-hole pair that led to the foreland thrust sheets, probably as a result of combined bulldozing and gravity spreading in the foreland of the ice margin. Their occurrence and the adjacent tunnel valleys leads us to assume that we identified the marginal position of an Elsterian ice lobe in the southeastern North Sea.</p><p>Reference:<br>Winsemann, J., Koopmann, H., Tanner, D.C., Lutz, R., Lang, J., Brandes, C., Gaedicke, C., 2020. Seismic interpretation and structural restoration of the Heligoland glaciotectonic thrust-fault complex: Implications for multiple deformation during (pre-)Elsterian to Warthian ice advances into the southern North Sea Basin. Quat. Sci. Rev. 227, 1–15. https://doi.org/10.1016/j.quascirev.2019.106068</p>

Reservoir sonics: A North Sea case study

Geophysics ◽  
1992 ◽  
Vol 57 (1) ◽  
pp. 146-160 ◽  
Author(s):  
Brian E. Hornby ◽  
William F. Murphy ◽  
Hsui‐Lin Liu ◽  
Kai Hsu
Keyword(s):  
North Sea ◽  
Cross Sections ◽  
Water Saturation ◽  
Compressional Wave ◽  
Normal Faulting ◽  
Compressional Wave Velocity ◽  
New Techniques ◽  
Seismic Migration ◽  
Full Waveform

Full waveform sonic data, acquired in a borehole penetrating a North Sea reservoir, were used to explore new techniques for analysis and interpretation of sonic data. Analysis of direct sonic arrivals included correlations with core‐derived permeability, inversion for compressional and shear velocities, and interpretation of compressional and shear velocities in terms of formation parameters. The velocities are found to be sensitive indicators of lithology and water saturation. In addition to the standard processing for compressional and shear velocities, inversion of sonic traveltimes resulted in a compressional wave‐velocity log with a 0.15 m vertical resolution. Using a process similar to prestack seismic migration, reflected sonic arrivals were used to form images of bedding features to a distance of 12 m from the borehole. The well intersects a region of strong normal faulting. Locations of high angle features and strong dip changes on the sonic‐derived images were consistent with the locations of faults indicated on the dipmeter‐derived structural cross‐sections.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Surface ultrastructure of danazol treated rat endometrium: A SEM study

1983 ◽  
Vol 41 ◽  
pp. 556-557
Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo
Keyword(s):  
Cross Sections ◽  
Reproductive Tract ◽  
Preliminary Investigation ◽  
Breast Disease ◽  
Distal Segment ◽  
Uterine Horn ◽  
Female Reproductive Tract ◽  
Ultrastructural Changes ◽  
Cycle Phase ◽  
Sprague Dawley

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

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