Magmatic suspensions represent a transitional phase in the evolution of magma to solid rock. Presence of suspended crystals has a significant effect on magma’s mechanical properties and plays a fundamental role in all major processes including transport, differentiation, and volcanic events. The mechanical processes are not only influenced by the volume percentage of crystals it contains, but also by their spatial arrangement. Crystals commonly show tendency to form clusters, which are abundant in both plutonic and volcanic rocks throughout their compositional range. In turn, presence of clusters alters mechanical behaviour of magma by facilitating processes such as crystal settling, and affects overall magma rheology. However, our understanding of why the clusters form and what mechanisms contribute to their formation remains incomplete.

The aim of this project is to investigate the internal dynamics of magmatic suspensions and formation of crystal clusters. To achieve this, multiple techniques including high-temperature and analogue experiments will be applied. The data collected from both experimental studies will be benchmarked against statistical parameters of cluster populations measured in natural magmatic suspension. As a “testing objects”, porphyritic lavas with olivine or pyroxene clusters from the České středohoří volcanic complex will be employed. Integrating laboratory and natural data aims to decipher the mechanisms responsible for formation and stabilization of clusters and temporal evolution of their population parameters. Consequently, evaluation of such parameters in natural crystal suspensions will provide constraints on the internal dynamics and environmental variables of their parental magmatic systems.

This project represents a continuation of our effort to decipher the crystallization processes in magmas based on study of spatial distribution of crystals in rocks (e.g., Špillar & Dolejš, Lithos, vol. 239; Špillar, Journal of Petrology, vol. 61). A successful applicant should be motivated in independent scientific work and skilled in experimental petrology and textural analysis and quantification methods.

Deadline for application: March 13, 2023

Research group

Magmatic Research Team

Research group leader

doc. Petr Jeřábek: jerabek.petr@natur.cuni.cz

Project supervisor

Dr. Václav Špillar: spillar@natur.cuni.cz

Apply to the project