Earth Sciences Seminar Room (Basement, WEB 05, the previous Mineralogy Seminar Room)
Wednesday 29th October 4.00 pm
Dr. Laurence A.J. Garvie, Center for Meteorite Studies, Tempe AZ 85287-6004 (lgarvie@asu.edu)
In 1806 a black, friable meteorite fell near the town of Alais in France. Subsequent chemical analysis published in the same year by Thenard showed that the stone contained 2.5 parts carbon and 18.5 parts water. In 1834, Berzelius showed that the stone contained clays and a complex suite of organic materials that were extracted with water. This study heralded the field of extraterrestrial organic chemistry.
The Alais stone belongs to a class of meteorites called carbonaceous chondrites (CC). These chondrites are primitive meteorites composed of various proportions of chondrules and refractory materials set in a fine-grained matrix. Their study provides important information on early Solar System processes. In addition, the matrix of these meteorites harbors a suite of presolar materials, some of which are carbonaceous.
Today, more than 40,000 organic compounds have been recognized in the CC meteorites, including more than 100 amino acids. Together with these soluble compounds, some CC meteorites contain an abundant carbonaceous component that is insoluble in water, solvents, and acids called the insoluble organic material (IOM). The IOM is chemically and structurally diverse and contains two easily recognizable and curious components – carbonaceous nanoglobules (also called organized elements) and nanodiamonds. I will explore the significance of these components to early Solar System studies as well as address the frequent past and present claims of indigenous microfossils in the carbonaceous chondrite meteorites.
More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/