Mechanisms of magma emplacement in the upper crust: Mechanismen der Platznahme von Magma in der Oberkruste
The mechanisms that control magma emplacement in the upper crust are characterised by brittle failure of the host rock and subject to the influence of magma. This thesis is a compilation of several case studies that address different aspects of magma emplacement by brittle mechanisms. Chapter 3 outl...
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| Language: | English |
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Niedersächsische Staats- und Universitätsbibliothek
2009
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| Online Access: | http://resolver.sub.uni-goettingen.de/purl/?webdoc-2112 http://nbn-resolving.de/urn:nbn:de:gbv:7-webdoc-2112-6 http://d-nb.info/1009513575/34 http://webdoc.sub.gwdg.de/diss/2009/burchardt |
| Summary: | The mechanisms that control magma emplacement in the upper crust are characterised by brittle failure of the host rock and subject to the influence of magma. This thesis is a compilation of several case studies that address different aspects of magma emplacement by brittle mechanisms. Chapter 3 outlines the results of a field study of the Njardvik Sill in the Tertiary Dyrfjöll Volcano in Northeast Iceland. This small basaltic sill provides insight into the mode of its emplacement along the interface between two mechanically contrasting materials, its feeding relationships with several inclined sheets, as well as the circumstances of its growth by episodic magma supply. Once initiated, the Njardvik Sill furthermore influenced the stress field in its surroundings that resulted in the diversion of subsequently injected inclined sheets into units of the sill. The results of detailed field analyses served as the basis for a simple numerical model of the mechanical conditions for the emplacement of the first sill unit. The study of the Njardvik Sill thus provides insight into the mechanism of sill emplacement particularly with regards to feeding relations, mechanical conditions for sill initiation, the influence of the magma-supply rate, and the mechanical effect of a sill on its surroundings . Sprache der Zusammenfassung: Englisch @Göttingen, Univ., GZG, Diss., 2009 lzar: Langzeitarchivierung gewährleistet |
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