| Popis: |
This subject warrants much fuller attention than we are able to give within the scope of this book. We therefore document the important physical and stratigraphic characteristics of modern volcanoes and volcanic centres, as a preliminary account before considering them within the context of general facies models for modern and ancient successions in Chapter 14. Our attention is focused here on individual volcanoes rather than on provinces, an important distinction, given the relatively short life-span of individual volcanoes compared with the longer lived, larger volcanic#x2014;sedimentary provinces of which they are part. Initially we concentrate on the volcanic forms commonly built by the subaerial eruption of basaltic magmas: basaltic shield volcanoes, flood basalt plateaus, scoria cones, maar-type craters, and also pseudocraters and littoral cones. Pumice-forming eruptions can also build steep-sided cones somewhat akin to scoria cones, and these are briefly mentioned. |
