In situ project

In situ isotope geochemistry of the Wiborg rapakivi granite batholith in Southern Finland

The Wiborg batholith is the largest and oldest of the rapakivi granite intrusions in the (1.65-1.52 Ga) rapakivi suite of Southern Finland. This Academy of Finland -funded project ran from 2012 to 2016 and it's primary goal was to produce a comprehensive data set of mineralogical and isotopic data on the different types of rapakivi-textured granite types in the batholith. My previous research activities also provided some insights into the petrogenesis of the Wiborg batholith and the Fennoscandian rapakivi suite as a whole. Specific papers and references can be found on the Publications -page.

Zircon studies

My main role in the project was to study the U-Pb isotope and trace element compositions of zircon  in different textural positions of the Wiborg rapakivi granites. To this end I have utilized a specialized micro-drill sampling technique to extract zircon from within different mineral phases to study their potential entrainment effect on the geochronological interpretations of the batholith granites.

 

Mapping and petrographic characterization of rapakivi ovoids in the main lithological rapakivi types

Rapakivi texture was first described from southern Finland already in the 1890s but it still remains elusive to genetic interpretations. It has been the aim of this project to produce a new petrographic and mineral chemical data set to evaluate the existing theories of rapakivi texture origin and potentially generate new ideas on how to approach the problem in the classic rapakivi location.

Emplacement and thermal history of rapakivi granite magmas in the Wiborg area

As an over-arching theme of the project has been to synthesize the achieved results into modern petrological and thermodynamic model frameworks. This includes the use of different modeling tools such as RhyoliteMELTS -software to constrain the emplacement and thermal history of the rapakivi magmas. This is essentially a work-in-progress...