1,721,488 research outputs found
Structural synthesis of the Northern Calcareous Alps, TRANSALP segment
No full textThe Northern Calcareous Alps (NCA) are the site of very large top-to-north convergent movements during Cretaceous–Tertiary Alpine mountain building. To determine the amount of shortening, the depth of detachment and the style of deformation, we retro-deformed an approximately 40 × 40 km area comprising the Lechtal and Allgäu Nappes. On the basis of all available geological data and processed sections of the TRANSALP reflection seismic experiment, coherent 3D models were constructed by splining lines from N–S cross-sections. Integration of 3D kinematic modeling and field data shows the following. The structure of the Lechtal Nappe is controlled by the Triassic Hauptdolomit. Four main thrusts link to a detachment at 2–6 km depth below sea level. Shortening estimates vary, from 25% (east) to 42% (west). Additional contraction is accommodated by folding. In the east the subjacent Allgäu Nappe can be traced about 10 km down-plunge, and is shortened by about one third. In the western part the downplunge width is at least 15–20 km, with restorable shortening of one third. The triple (Inntal, Lechtal, Allgäu Nappes) NCA nappe system was moved uniformly N–S to produce laterally heterogeneus shortening of 40–90 km or 50–67%. We suggest that the NCA are underlain by substantial amounts of buried Molasse sediments and/or overthrust units of Helvetic and Rheno-Danubian Flysch, indicating post-Eocene N–S shortening of at least 55 km. Restored to an initial configuration, the basin topography of the NCA reveals strong E–W thickness variations of the Triassic Wettersteinkalk and Hauptdolomit platform carbonates. Such variations may pertain to N–S trending growth faults, which were important precursors to later Jurassic extension of the Austroalpine passive margin. Such structures are unlikely to be seen in the conventional N–S cross-sections, but form an essential geometrical and mechanical element in later, convergent mountain building
Strukturgeologische 3D-Modellierung der Grabenrandstörung des Leinetals im östlichen Stadtgebiet von Göttingen
No full textIm Rahmen von verschiedenen Geothermie-Projekten wurden im östlichen Stadtgebiet von Göttingen Bohrungen beprobt, analysiert und beschrieben. Die Bohrung 2 (Tannenweg 20) durchteufte dabei die hier unter der Lias-Gruppe liegende, östliche Grabenrandstörung und traf auf Gipse des Mittleren Muschelkalkes. Für einen Aufstieg von Zechstein-Evaporiten entlang der Grabenrandstörung, so wie vormals vermutet, finden sich damit keine Belege. Unter Einbindung von weiteren Bohrungen und Fundstücken aus dem Museum des GZG sowie Fundangaben aus geologischen Kartierungen des frühen 19. Jahrhunderts hat sich der Verlauf der östlichen Grabenrandstörung gegenüber der publizierten Karte von Stille (1932) um etwa 100m in Richtung Osten verschoben. Weiterhin zeigte sich in der erstellten, geologischen Karte, dass eine dextrale Seitenverschiebung eine Umbiegung der Lias-Schichten im Norden und einen dextralen Versatz der östlichen Grabenrandstörung von etwa 70m verursacht. Das generierte, strukturgeologische 3D-Modell zeigt, dass die Basis der als Leithorizont genutzten Lias-γ-Kalksteinbank im n¨ordlichen Bereich einen ausgeprägten Knick aufweist und mit 30°steiler als der südliche Bereich einfällt. Ferner konnte anhand der 3D-Modellierung die Orientierung der östlichen Grabenrandstörung mit 289/55 ermittelt werden. Abstract— Within the context of various geothermal projects, wells were sampled, analysed and described from the eastern side of the city of G¨ ottingen. The well No. 2 (Tannenweg 20) encountered, in addition to the Lower Jurassic Lias Formation, the eastern Leinetal border fault and then gypsum layers of the Middle Muschelkalk. The previous assumption that Zechstein had risen along the border faults, could not be confirmed in this work. With the information from wells and finds from the museum of the GZG, and geological maps and their memoirs from the early 19th Century, the trace of the main eastern border fault was moved about 100 metres toward the east. From the resulting geological map it becomes apparent that a dextral strike-slip fault caused a bend in the Liassic strata to the north and a dextral displacement of the eastern border fault by ca. 70 metres. The generated 3D structural geological model indicates that the base of Lias γ horizon in the northern area has a pronounced bend and dips 30°steeper than the southern area. By the use of 3D modelling, it was possible to determine that the orientation of the eastern border fault in this area is 289/55
Joseph Smith Tanner, Freeman E. Tanner, Seth U. Tanner, Myron Tanner, David Don Tanner, Louisa Marie Lyman, and Nathan Tanner. Circa 1896
No full textSepia photograph of Joseph Smith Tanner, Freeman E. Tanner, Seth U. Tanner, Myron Tanner, David Don Tanner, Louisa Marie Lyman, and Nathan Tanner. Circa 1896
Modelling the Geothermal Potential of the Eastern Border of the Leinetal Graben, Lower Saxony
No full textMulti-stage emplacement of the Götemar Pluton, SE Sweden: new evidence inferred from field observations and microfabric analysis, including cathodoluminescence microscopy
Full text linkThe emplacement of the Mesoproterozoic Götemar Pluton into Paleoproterozoic granitoid host rocks of the Transscandinavian Igneous Belt is re-examined by microfabric analysis, including cathodoluminescence microscopy. Field data on the pluton-host rock system are used to strengthen the model. The Götemar Pluton, situated on the Baltic Shield of SE Sweden, is a horizontally zoned tabular structure that was constructed by the intrusion of successive pulses of magma with different crystal/melt ratios, at an estimated crustal depth of 4–8 km. Initial pluton formation involved magma ascent along a vertical dike, which was arrested at a mechanical discontinuity within the granitoid host rocks; this led to the formation of an initial sill. Subsequent sill stacking and their constant inflation resulted in deformation and reheating of existing magma bodies, which also raised the pluton roof. This multi-stage emplacement scenario is indicated by complex dike relationships and the occurrence of several generations of quartz (Si-metasomatism). The sills were charged by different domains of a heterogeneous magma chamber with varying crystal/melt ratios. Ascent or emplacement of magma with a high crystal/melt ratio is indicated by syn-magmatic deformation of phenocrysts. Complex crystallization fabrics (e.g. oscillatory growth zoning caused by high crystal defect density, overgrowth and replacement features, resorbed and corroded crystal cores, rapakivi structure) are mostly related to processes within the main chamber, that is repeated magma mixing or water influx
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
A numerical sensitivity study of how permeability, geological structure, and hydraulic gradient control the lifetime of a geothermal reservoir
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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