Abstract: The flow of fluids and melts in ductile rocks is a fundamental process in many geological and planetary processes. The dynamics of fluid flow in ductile rocks is fundamentally different from standard porous flow in rigid or elastic rocks. Initially will focus on the pore-scale distribution of fluids in ductile rocks. The percolation of fluids in ductile rocks is thought to be governed by textural equilibrium. In the first part of this talk we test this hypothesis with laboratory experiments on rock salt and show that it can explain fluid distributions in salt from exploration wells in the Gulf of Mexico. Our results suggests that salt domes may be conduits for fluid flow at depth. In the second part, we explore hysteresis in texturally equilibrated pore networks. This work is motivated by the long-standing problem of core formation in primordial planetesimals, where segregation of metalsulfide melt is thought to be prevented by a percolation threshold. We compute the texturally equilibrated melt networks in realistic polycrystalline rocks and demonstrate that despite the percolation threshold the metal-sulfide melts can be drained due to hysteresis in melt network connectivity. This suggests that core formation by melt percolation is possible in primordial planetesimals, which may explain early core formation in these bodies. The third part of this talk will focus on melt transport at larger scales. At the Darcy-scale fluid low in ductile rocks inevitably leads to the formation of porosity waves. This work is motivated by oxidant transport through Europa’s ice shell. Using a Lagrangian analysis of melt transport we demonstrate that porosity wave can transport geochemical signatures over long distances. Preliminary results on kinematics of melt transport show that melt transport in porosity waves is robust in the presence of perturbations. This suggests that porosity waves provide a potential mechanism for oxidant transport from the surface to the internal ocean.

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