Amit Meltzer

Amit Meltzer
Ph.D candidate
supervised by Ronit Kessel
Room 104 South

 

Research interests: experimental petrology, geochemistry of high-pressure high-temperature fluids, thermodynamic modelling.

Research topic: The metasomatism and evolution of high-density fluids.

Abstract: Deep earth fluids and melts play an important role in geochemical cycles of key volatile elements. Aspects of the chemical characterization of these fluids, its mass transfer between mantle regions and the alteration ability in the metasomatic processes are still enigmatic. Recent studies of direct chemical analysis of high-density fluids (HDF) found unaltered as micro-inclusions inside diamonds that may represent pristine mantle fluids, provide an opportunity to study mantle metasomatism. These studies focused on the geochemical characterization and possible origin of these fluids. In my research I try to draw a new direction in the experimental and theoretical research of these fluids, its geochemical evolution between the different compositions and their influence on the mantle protolith in the alteration reactions.

In my experimental projects, I investigate the interaction of different HDFs – silicic and saline – with a peridotitic lithology at mantle pressure and temperature conditions. Using multi-anvil experiments, cryogenic LA-ICP-MS technique for direct analysis of the fluids, and EPMA examination of mineral assemblage, I characterize the reactions in these metasomatic interactions. Using the new knowledge from the experimental projects to update current thermodynamic models and employing new statistical algorithms on current available data, I try to better understand the trends of HDFs compositional evolution and their involvement in mantle metasomatism. Integration of these studies can help genetically relate the metasomatic phases found in mantle xenoliths and diamond inclusions to diamond forming fluids percolating the refractory mantle. Such a study may be important in understanding the pivotal role of deep aqueous fluids in maintaining the Earth’s long-term planetary habitability.