Petrologic Significance of Low Heat Flow on the Flanks of Slow-Spreading Midocean Ridges
A compilation of heaf flow versus age of oceanic crust about all the midocean ridges demonstrates that low heat-flow anomalies associated with the crest and flanks appear to occur only on slow-spreading ridges. Such crestal anomalies are probably caused by large-scale hydrothermal circulation in fractures throughout the riewly formed oceanic crust, which results in rapid cooling of the crestal zone and hydration of the crust. Away from the crest, sediments seal the fractures and circulation stops. The crust then begins to heat until it reaches equilibrium with the conductively cooling mantle, after which it cools with the rest of the lithospheric plate
If, however, the crust heats to above the equilibrium stability temperature for its hydrous assemblage, dehydration occufe, absorbing enough, heat to produce the observed low heat flow on the flanks of these slow spreading ridges.
Figures & Tables
Edited by Peter A. Roma and published in 1976, Mid-Atlantic Ridge contains a collection of related articles reprinted from other Geological Society of America publications as well as a brief review of exploration of the Mid-Atlantic Ridge from 1960 to 1975.