Holger Sommer undertakes research within the areas of petrology, mineralogy and geochemistry. His work on metamorphic and igneous petrology deals with the formation and recycling of continental and oceanic crust from the microscale to the macroscale. This work employs analytical facilities including SHRIMP, EPMA and LA-ICPMS, and software such as PerPleX and TWQ. His mineralogical work assesses components of the planetary volatile cycle, including water and carbon dioxide. He uses Synchrotron Based FTIR with a micrometre-scale resolution to determine the distribution of volatiles in Nominally Anhydrous Minerals. His geochemical interests lie in understanding the distribution of REE, LREE and HREE in the granulite-eclogite facies transition zone. Holger Sommer has undertaken research in the USA, Greenland, Germany, Morocco, Tanzania, Botswana, Namibia, Lesotho, South Africa, Antarctica and Fiji
