Journal of Conference Abstracts

Transfer of the Mantle Fluid into the Lower Continental Crust

Vladimir Cherniavski (cherniav@chip.sio.rssi.ru)¹ & Elena Suetnova (vera@analit.msk.ru)²

¹Paleogeodynamics lab., Institute Oceanology, Krasikova 23, Moscow, 117218, Russia

²E.I. Suetnova, Profsoyuznaya 99-80, Moscow, 117279, Russia

The infiltration of the continental lower crust by the mantle derived volatiles may have important consequences for the nature and evolution of the lower crust and for the thermal structure and rheology of continental lithosphere. Pore pressure affect on rheology of the lower crust and seismic velocity. High seismic reflectivity coincided with low resistivity observed in some regions have been attributed to presence of free fluid in the lower crust.

Therefore it appears important to examine the dynamic of fluid movement at the lower crust-upper mantle depth. The models are suggested to account free fluid movement at the vicinity of mantle-crust boundary for two different cases of the boundary conditions. In the first case the fixed lower boundary of the problem is considered. Such the condition correspond to stable continental regions. Moving lower boundary (case 2) corresponds to a number of geophysical events related to the active processes in the mantle. Analytical and numerical results of the modeling are compared with seismic studies of the lower crust at collision zones and sedimentary basins. Time dependent behavior of overpressure zones in the deep crust is accounted. Influence of fluid on the deformation processes of the deep crust are discussed.