ON THE THERMAL REGIME OF SOME TECTONIC UNITS IN A CONTINENTAL COLLISION ENVIRONMENT IN ROMANIA

An analysis of the evolution of the main tectonic units in Romania sho ws that the thermal regime of the lithosphere should be derived accord ing, on the one hand, to the particular tectonic interactions the vari ous tectonic units have been involved in and, on the other hand, to th e investigated depth interval. A steady-state conduction model of the crustal temperature field based on the heat flow distribution and info rmation on the structure is presented for the Romanian territory. It s hows large lateral thermal variations between tectonic units, as a res ult of different geological and thermal histories. Within the frame of a complex modelling of the thermal evolution of the lithosphere in th e East Carpathians, as proposed in this study, the zero-order thermal effects of the pre-Miocene oceanic subduction of the Eurasian plate ar e evaluated. The deep thermal structure of the subducted slab is deriv ed and shown to be compatible with the velocity structure of the litho sphere and the intermediate-depth seismicity of the Vrancea area.