Heat Flow as an Indicator of the Dynamics of Deep Processes Occurring in Marginal Seas and Island Arcs of the Northwestern Pacific

摘要: High heat flow is characteristic of most back-arc basins and island arc volcanic fronts. Numerical calculations comparisons with other geophysical geochemical data show that the excess sources are distributed at depths about 20–40 km, where there layers characterized by high electrical conductivity low velocities seismic waves. A discussion available leads to conclusion such contain melts ultrabasic composition, temperature which reaches 1500 ± 100° C. Injection high-temperature (magmas) from 350–400 km into uppermost mantle suggested as realistic mechanism for providing rapid transport thus formation zones or melted material. By this scenario deep processes, rising create pressure originates difference between their density surrounding medium, and, a result, extension failures produced. These failure zones, in turn, become channels melts. At levels comparable host intrude mainly lateral directions according hydrofracture megasills form.