Environmental mineralogy by QEMSCAN®

Resin-impregnated plug recovered from a core taken from the Hayle Estuary, Cornwall, UK, showing the impact of historical mining. The image shows pre-mining sediments in purple (mostly marine-derived carbonate sands) overlain by laminated muds (brown/red-purple) containing heavy minerals such as cassiterite, pyrite, chalcopyrite, sphalerite and galena.
The image is 27 mm diameter scanned at 10 microns X-ray resolution.

The importance of understanding mineralogy related to contaminated soils and sediments has been highlighted for a number of years by researchers  at the Camborne School of Mines, University of Exeter, UK. Duncan Pirrie, Gavyn Rollinson and Matthew Power have examined samples taken from both estuaries and contaminated land (e.g. Pirrie et al. 2009*).

During these studies automated mineralogy (QEMSCAN®) has successfully been used as a tool to help characterise mineralogy, locate trace phases and determine diagenetic alteration that may lead to bio-availability of heavy metals. In combination with bulk chemistry and mineralogy techniques such as x-ray fluorescence (XRF) and X-ray diffraction (XRD), our understanding of environmental mineralogy can be improved and environmental processes be better understood and managed.

* Pirrie, D., Rollinson, G.K., Power, M.R. 2009. Role of automated mineralogy in the assessment of contaminated land. Geoscience in SW England, 12. 162-170.

Ash from Eyjafjallajokull, S. Iceland 2010

Ash particles from Eyjafjallajökull 2010, analysed by QEMSCAN®

Researchers at the Camborne School of Mines (CSM), University of Exeter, UK, have examined ash samples taken on Iceland during the volcanic eruptions in 2010. Work was undertaken by Dr Gavyn Rollinson and Dr Duncan Pirrie, with samples taken by Dr Stuart Bearhop who was on fieldwork on Iceland at the time of the eruptions.

The ash sample mineralogy reflects the geology of Iceland being dominated by plagioclase feldspar (cyan) and other silicates (olivine, pyroxenes/amphiboles, clays) with glass phases, minor ilmenite and Ti-magnetite. Grain sizes are <30 microns, and generally <15 microns. Initial work was presented by Dr Alan Butcher of FEI at the INQUA XVIII conference in Bern, Switzerland, Saturday 23^rd July 2011.

The study demonstrates the value of automated mineralogy to airborne pollution and builds on previous and current work being carried out on air particulates at the Camborne School of Mines.

QEMSCAN studies of metamorphic rock samples

Identification of key minerals is of great importance to determining the tectonic history of metamorphic samples. These key minerals may be few in number and present only as small micro-inclusions making them difficult to identify, if at all, with a petrographic microscope.


Once relict minerals of earlier metamorphic assemblages are located, thermobarometry and geochronology can then be applied, resulting in a wealth of information on previous segments of the pressure-temperature-time-deformation path. The relict mineral textures and their relationship to the fabric of the entire thin section can be easily seen in mineral maps yielding important textural information.


The QEMSCAN at the Camborne School of Mines (CSM) is being used to study metamorphic samples from the Central Metamorphic terrane of the Eastern Klamath Mountains, Northern California.


Intial results were presented at the European Geosciences Union, General Assembly, Vienna, 2-7 May 2010 "Application of Automated SEM-EDS Based Mineral Identification Systems to Problems in Metamorphic Petrology" by Robert Fairhurst, Wendy Barrow and Gavyn Rollinson.