A dynamic mantle-lithospheric interaction model for mature stage continental tectonics: Implications for the Basin and Range Province in the western U.S.
published: Jan 1, 2003
Open Access (paper can be downloaded for free)
The observations of gravity, heat flow and crust-mantle seismic velocities for the Basin and Range as well as other physiographic provinces show correlations between the extent of low compressional velocity zones in the upper mantle, the observed heat flow and Bouguer gravity anomalies. In view of these observations and the low Q values (the seismic wave energy dissipation factor) throughout such an upper mantle low velocity zone, it is likely, if not certain, that the low compressional velocity region is indicative of partial melting. From this point of view high regional heat flow observations and correlated negative Bouguer anomalies are due to partial melting and are of mantle origin. Calculations show that such a geophysical model is in agreement with the observations if mantle material is partially molten at low temperatures (875 °C at 40 km); implying the presence of a small amount of water.