Marian Holness

Research Area

I am interested in the processes which occur during magma solidification, combining geochemical evidence and microstructures to constrain the history of crystal growth, magma convection and the behaviour of any crystal mushy regions, such as permeability, physical strength to compaction or disaggregation, and recrystallisation. Obtaining a detailed understanding of the development of magmatic systems requires accurate spatial information, so my work has a strong field component: I have projects underway in Northern Ireland, East Greenland and the Scottish Hebrides. I also have an interest in the solid-state processes that occur during reaction in metamorphic rocks and their consequences for rock behaviour.

Project Interests

I am interested in developing experimental studies to explore the physical behaviour of magma bodies in which the liquid has unmixed into two silicate liquids (one Fe-rich and the other Si-rich). The two liquids have different affinities for the various mineral phases on the liquidus, leading to changes in crystal settling velocities in the bulk magma once it has split to form an emulsion, and complex changes in the physical behaviour of crystal mush developing on the margin of magma bodies, such as the rate of liquid percolation and compaction. The results of such experimental studies would be of broad applicability to problems related to ore deposit formation. There are also numerous other problems of interest, including an examination of the effects of cooling rate on microstructures in silicic rocks, the microstructures of zeolite growth in late-stage magmatic systems, and the behaviour of crystal slurries in large magma bodies.

Potential CASE Collaborations

The Geological Survey of Northern Ireland

The Geological Survey of Denmark and Greenland (GEUS)