In defense of magmatic diapirs

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doi: 10.1016/S0191-8141(99)00033-4
Authors:Miller, Robert B.; Paterson, Scott R.
Author Affiliations:Primary:
San Jose State University, Department of Geology, San Jose, CA, United States
Other:
University of Manchester, United Kingdom
University of Southern California, United States
Volume Title:Questions in structural geology; 20th anniversary special issue
Volume Authors:Evans, James P., editor; Treagus, Susan H.
Source:Questions in structural geology; 20th anniversary special issue, edited by James P. Evans and Susan H. Treagus. Journal of Structural Geology, 21(8-9), p.1161-1173. Publisher: Pergamon, Oxford-New York, International. ISSN: 0191-8141
Publication Date:1999
Note:In English. 48 refs.; 1 table, sects., geol. sketch maps
Summary:There has been much recent criticism of diapirism as a viable crustal magma ascent mechanism. It is suggested that much of this criticism comes from the overly simplistic view that diapirs must resemble modelled hot-Stokes diapirs, and from the perception that magma ascent in dykes is a more problem-free mechanism for pluton construction. Four Cordilleran plutons emplaced at 10-30 km depth and which record different parts of diapiric ascent paths, are described. They ascended during complex visco-elastic flow of host rock during regional deformation, have narrow structural aureoles indicating power-law behaviour of host rock and were constructed from multiple batches of magma, all of which enabled them to ascend greater distances than single hot-Stokes diapirs. Some features of these plutons are not typically attributed to diapirs, and thus the term visco-elastic diapir is introduced for bodies comprising one or more magma batches rising together (length:width ratios < 100) surrounded by host rock deforming by brittle and ductile processes, and whose ascent is driven by buoyancy plus regional stress. It is concluded that diapirism remains a valid magma ascent mechanism for the crust. [J.F.]
Sections:Petrology
Subsections:Igneous petrology
Subjects:Cenozoic; Diapirs; Emplacement; Folds; Intrusions; Magmatism; Mesozoic; Plutons; California; Cascade Range; Inyo County California; North America; North American Cordillera; Panamint Range; Southern California; United States; Entiat Pluton; Hall Canyon Pluton; Oval Peak Pluton; Tenpeak Pluton
Abstract Numbers:00M/927
Record ID:1999059223
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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