Topographic controls on dike injection in volcanic rift zones
MetadataShow full item record
Dike emplacement in volcanic rift zones is often associated with the injection of “bladelike” dikes, which propagate long distances parallel to the rift, but frequently remain trapped at depth and erupt only near the tip of the dike. Over geologic time, this style of dike injection implies that a greater percentage of extension is accommodated by magma accretion at depth than near the surface. In this study, we investigate the evolution of faulting, topography, and stress state in volcanic rift zones using a kinematic model for dike injection in an extending 2-D elastic-viscoplastic layer. We show that the intrusion of blade-like dikes focuses deformation at the rift axis, leading to the formation of an axial rift valley. However, flexure associated with the development of the rift topography generates compression at the base of the plate. If the magnitude of these deviatoric compressive stresses exceeds the deviatoric tensile stress associated with far-field extension, further dike injection will be inhibited. In general, this transition from tensile to compressive deviatoric stresses occurs when the rate of accretion in the lower crust is greater than 50-60% of the far-field extension rate. These results indicate that over geologic time-scales the injection of blade-like dikes is a self-limiting process in which dike-generated faulting and topography result in an efficient feedback mechanism that controls the time-averaged distribution of magma accretion within the crust.
Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 246 (2006): 188-196, doi:10.1016/j.epsl.2006.04.005.
Suggested CitationPreprint: Behn, Mark D., Buck, W. Roger, Sacks, I. Selwyn, "Topographic controls on dike injection in volcanic rift zones", 2006-04-03, https://doi.org/10.1016/j.epsl.2006.04.005, https://hdl.handle.net/1912/1178
Showing items related by title, author, creator and subject.
Tessler, Zachary D.; Gordon, Arnold L.; Pratt, Lawrence J.; Sprintall, Janet (American Meteorological Society, 2010-12)Observations of stratification and currents between June 2007 and March 2009 reveal a strong overflow between 400- and 570-m depth from the Panay Strait into the Sulu Sea. The overflow water is derived from approximately ...
An asymmetric upwind flow, Yellow Sea Warm Current : 2. Arrested topographic waves in response to the northwesterly wind Lin, Xiaopei; Yang, Jiayan (American Geophysical Union, 2011-04-29)A warm and salty water mass exists along the Yellow Sea Trough (YST) in winter. This oceanic water mass is distinct from the ambient shelf water and is distributed on the western side of the YST. It has long been reasoned ...
Shelf circulation and cross-shelf transport out of a bay driven by eddies from an open-ocean current. Part I : interaction between a barotropic vortex and a steplike topography Zhang, Yu; Pedlosky, Joseph; Flierl, Glenn R. (American Meteorological Society, 2011-05)This paper examines interaction between a barotropic point vortex and a steplike topography with a bay-shaped shelf. The interaction is governed by two mechanisms: propagation of topographic Rossby waves and advection by ...