Fluid-magmatic interaction between Glaucophane schist and olivine: Experimental modeling under the conditions of a thermal gradient

Abstract

The subduction of a lithospheric plate into the mantle in subduction zones is accompanied by increase of temperature and pressure. The occurring mineral reactions of dehydration result in release of huge volumes of aqueous fluid from the plate [1]; this plays a key role in the processes of mantle metasoma� tism, magmatism, and recycling of chemical elements in subduction zones. A significant contribution to the study of complex processes in subduction zones was made by experimental investigations of phase equilib� ria [2, 3], solubility of minerals [4], and dehydration melting [5, 6] in various lithological rock types. How� ever, these experiments performed under isothermal– isobaric conditions cannot reveal the petrological and geochemical peculiarities of rock interaction between the oceanic crust and the mantle occurring at the same depth, but at different temperatures [7]. This feature of the thermal structure of the subduction zone may be simulated in the piston–cylinder apparatus. In this paper we describe the first results of such experiments, in which glaucophane schist and olivine were applied as the model analogs of the crust and the mantle, respectively.