Research

Life on Earth builds diverse biomolecules, many of which have complex exquisitely ornate chemical structures. The latter are designed perform a wide range of biological functions from encoding and propagating genetic information, to orchestrating specific cellular processes, through to maintaining the structural integrity of the organism. Of the plethora of biomolecules synthesized, most are rapidly recycled to carbon dioxide upon death of the organism. However, those that persist in the environment can be used to explore the carbon cycle and provide a lasting record of how it has operated in the past. Eglinton and his colleagues exploit these “legacy molecules” to trace organic matter produced by both terrestrial and aquatic organisms from biological source to sedimentary sink. Recent analytical advances in molecular characterization techniques that probe the distribution and stable isotopic composition of these legacy compounds afford information not only on biological source but also the environmental conditions experienced by the precursor organisms.

Although much has been learned about the types of information embedded in these molecular signatures, this rich archive remains only partially deciphered. Moreover, we have only a limited understanding of the mechanisms and timescales involved in organic matter cycling in the environment. This latter question lies at the core of the Biogeoscience group’s research activities. In order to address this question, they use a key attribute of organic matter – its radiocarbon age. Eglinton has pioneered methods for radiocarbon dating at the molecular level and uses this information as a “clock” to explore the timeframe over which specific pools of carbon moves within and between different Earth surface reservoirs. This information is used in tandem with other molecular and isotopic attributes to examine carbon cycling in contemporary and Late Quaternary terrestrial and oceanic environments, and to infer past changes in organic matter cycling deeper in the geologic record.

Research within the Biogeoscience group is presently organized around several cross-cutting themes that examine the sources, transport and transformations, burial, and sedimentary legacy of biospheric carbon, as well as climate-related and anthropogenic influences on these processes. We follow several general approaches in our investigations. In addition to detailed laboratory investigations to probe chemical characteristics and glean biological and environmental information from organic matter, our studies involve extensive fieldwork in diverse terrestrial and oceanic environmental settings.

Research

Themes