Ed Grew is Pardee Symposium Speaker at Geological Society of America Meeting
Research Professor Ed Grew gave an invited Pardee talk “Evolution of the Minerals of Beryllium, and Comparison with Boron Mineral Evolution” at the GSA meeting in Denver on November 1, 2010. Robert Hazen of the Geophysical Laboratory, Carnegie Institution for Science, organized the Pardee Keynote Symposium, “Mineral Evolution: The Coevolution of the Geo-and Biospheres.” In 2008, Hazen had invited Ed to collaborate on research in the emerging topic of mineral evolution. Pardee Symposia are interdisciplinary sessions addressing broad, fundamental issues in geosciences, and the session on mineral evolution drew a large audience. Ed’s talk, co-authored with Hazen, concerned the evolution of the 107 known mineral species of beryllium. The oldest beryllium mineral yet reported in the scientific literature is emerald from the 3 billion year old Gravelotte deposit in South Africa. The photograph shows beryl crystals from an Early Cambrian pegmatite that Ed collected on one of his expeditions to Antarctica. Ed discussed how episodic increases in species diversity in boron and beryllium minerals appear to correspond with certain models of supercontinent distribution in the Precambrian. Ed also discussed obstacles in the study of mineral evolution. The geologic record is very incomplete, as there are major gaps due to erosion, metamorphism and subduction. There are 262 known minerals of boron, but boron deposits with high species diversity such as evaporites (for example, the borate ulexite) are rarely preserved in Precambrian rocks, and determining boron mineral evolution is thus much more difficult.