Title Organizing melt flow through the crust
Author Brown, M.; Korhonen, F.J.; Siddoway, C.S.
Author Affil Brown, M., University of Maryland, Department of Geology, Laboratory for Crustal Petrology, College Park, MD. Other: Curtin University, Australia; Colorado College
Source Elements, 7(4), p.261-266. Publisher: Mineralogical Society of America and Mineralogical Society of Great Britain and Ireland and Mineralogical Association of Canada and Geochemical Society and Clay Minerals Society, International. ISSN: 1811- 5209
Publication Date Aug. 2011
Notes In English. 31 refs. GeoRef Acc. No: 308797
Index Terms Antarctica--Fosdick Mountains; United States--Maine; Antarctica--West Antarctica; anatexis; Antarctica; brittle deformation; continents; crust; deformation; dikes; ductile deformation; ductile-brittle transition; fabric; Fosdick Mountains; fractures; fracturing; granites; granulites; igneous rocks; intrusions; lower crust; Maine; Marie Byrd Land; melts; metamorphic rocks; migmatites; orogenic belts; orogeny; permeability; plutonic rocks; porosity; pressure; shear zones; strain; stress; United States; West Antarctica; western Maine
Abstract Melt that crystallizes as granite at shallow crustal levels in orogenic belts originates from migmatite and residual granulite in the deep crust; this is the most important mass-transfer process affecting the continents. Initially melt collects in grain boundaries before migrating along structural fabrics and through discordant fractures initiated during synanatectic deformation. As this permeable porosity develops, melt flows down gradients in pressure generated by the imposed tectonic stress, moving from grain boundaries through outcrop-scale vein networks to ascent conduits. Gravity then drives melt ascent through the crust, either in dikes that fill ductile-to-brittle-elastic fractures or by pervasive flow in planar and linear channels in belts of steep structural fabrics. Melt may be arrested in its ascent at the ductile-to-brittle transition zone or it may be trapped en route by a developing tectonic structure.
URL http://hdl.handle.net/10.2113/gselements.7.4.261
Publication Type journal article
Record ID 91277