IT TAKES ABOUT 40-80 MILLION YEARS FOR SUBDUCTED OCEANIC CRUST TO WARM UP TO THE MELTING POINT OF ECLOGITE. BECAUSE DELAMINATED ROOTS ARE ALREADY WARM THEY MELT IN ABOUT HALF THE TIME. THE ENERGY SOURCE IS THE ESSENTIALLY INFINITE HEAT CONTENT OF THE MANTLE ITSELF, NOT THE CORE.ECLOGITE BLOBS ARE NOT THERMAL BOUNDARY LAYER INSTABILITIES, E.G. PLUMES.