Mineral micro-inclusions as a petrogenetic indicator: a view from the modern oceanic lower-crust assemblages
Primary Investigator: Prof. Mag. Dr. Rainer Abart
Funding Organisation: FWF (Austrian Science Fund)
Abstract: The project is devoted to the fundamental geological problem of phase composition and behavioru of multicomponent crystal matter during changes of physical-chemical conditions. It relies on the potential of mineral structure and phase composition for reconstructing geological processes. Specifically the genesis of solid-phase micro inclusions hosted in rock-forming minerals and their fate in a dynamic geological environment will be addressed using state of the art electron beam micro-analytical techniques. Due to their insignificant geological age (less than 10 Ma), gabbros from Mid-Ocean Ridges are particularly well suited for studying the behaviour of micro-inclusions. These gabbros experienced a relatively short geological history with relatively few rock forming events, which are much easier to unravel than the complex petrogenetic history of rocks from geodynamic settings with a long geological history. The genesis and fate of solid-phase micro inclusions hosted in rock-forming minerals of Mid-Atlantic Ridge gabbros at 13°30’-13°35’N will be investigated. In particular the genesis and the post formation behaviour of the mineral micro-inclusions will be examined in the context of felsic magmatism and hydrothermal alterations affecting the gabbros. The evolution of the microstructural and textural features of the micro-inclusion and their relations to the host phases as well as the chemical characteristics of the mineral micro-inclusions will be correlated with available petrographic and geochemical data. By this new insights into the information content of mineral micro-inclusions and into the petrogenetic history of Mid-Atlantic Ridge gabbros will be obtained.