Controls on extrusion at mid-ocean ridges

Publication Type  Journal Article
Year of Publication  1997
Authors  Buck, W. R.; Carbotte, S. M.; Mutter, C.
Journal Title  Geology
Volume  25
Issue  10
Pages  935-938
Journal Date  Oct
ISBN Number  0091-7613
Accession Number  ISI:A1997YB06200018
Key Words  east pacific rise; seismic structure; spread profiles; midocean ridges; crust; beneath; 9-degrees-n; density; systems; crest

A magma lens can erupt to form extrusives only if it is under greater pressure than the static pressure in a column of magma reaching from the lens to the surface, The excess pressure results partly from overburden pressure caused by the presence of high-and low-density rocks (dikes and extrusives, respectively) above the lens. The thicker the pile of low-density extrusives, the lower the average overburden density. Thus, extrusion above a lens should be self-regulating, in that thickening the extrusive layer reduces the driving pressure for subsequent eruptions. Flexural stresses may affect extrusion by altering the pressure on a magma chamber. For ridges lacking an axial valley, we predict that deeper magma lenses should correlate with thicker extrusive layers, consistent with recent observations.


Yb062Times Cited:17Cited References Count:37

URL  <Go to ISI>://A1997YB06200018