Published online by Cambridge University Press: 18 April 2020
How does magma move or rise from its source chamber to the surface? More specifically, how does magma generate a path to the surface so as to supply magma to an eruption? Or, in general, under what conditions do dike-fed eruptions occur? While these questions have been briefly mentioned in some of the earlier chapters, they and the answers have not been discussed in detail. That I shall do in the present chapter. While magma moves through the crust by different mechanisms (e.g. as diapirs), the main mechanism is magma-driven fractures. The general name for all magma-driven fractures, once solidified, is sheet intrusions or sheets, which include dikes, inclined sheets, and sills. Unless stated otherwise, the theoretical discussion in this chapter applies equally to all these three types of sheets. Here, the focus is on mostly dikes, partly for the simple reason that dikes supply magma to most eruptions. For general theoretical considerations, dike denotes both subvertical dikes, regional and local, and commonly also inclined sheets, although in some instances a distinction will be made between these structures.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.