UCL Earth Sciences


Todd Downing

“Investigating layered alkaline igneous rocks and element enrichment processes to improve our understanding of the formation and location of economically important metal ore deposits.”

PhD project title:

Investigating novel metasomatic processes at the Ilímaussaq Complex, South Greenland.

Todd Downing
Project description:

The Ilímaussaq Complex in South Greenland exhibits world-class examples of macroscopic layering achieved by variable concentrations of red-white and black minerals, in largely sub-horizontal aspect, considered undeformed since their formation ~1160 Ma ago. Some of the rock-forming minerals contain elements of high economic value (e.g. Zr, REE), as assessed by systematic field drilling campaigns. We question whether or not the macroscale fabric is primary (igneous, two models) or secondary (metasomatic, new), which will be evaluated.

Four main tasks are identified (1) lab-based fluid-rock high pressure/temperature (HPT) time-resolved geochemical experiments using natural rock samples (2) fluid-inclusion analyses (3) field mapping using aerial high-resolution imaging (drone/3D) in Greenland and (4) software modelling to convert the drone imagery to 3D models, and to interpret the geochemical experimental data against petrogenetic models. The project combines geochemistry, experimental petrology and digital field mapping to investigate the effect of novel metasomatic processes in the formation of macroscale layering at Ilímaussaq and its associated enrichment. This will provide the opportunity to improve our understanding of metasomatism and the formation and location of economically important metal ore deposits.