Dr. Steven Denyszyn School of Earth and Environment Centre for Exploration Targeting, University of Western Australia
The Precambrian accounts for nearly 90% of Earth history, yet it remains generally poorly-understood due to a decreasing amount of primary Earth materials available for study. As we make progress toward unravelling the complex history of Earth’s first four billion years, it is apparent that reconstructions of Precambrian geography, climate, biotic evolution, and geological events all depend upon accurate geochronology. And as we refine our reconstructions, geochronological information must provide higher temporal resolution in order to distinguish discrete geological events from one another, and to establish rates of tectonic, evolutionary, or environmental processes. This presentation will include an overview of the fundamentals behind radio-isotopic geochronology, with a focus on the U-Pb method. There will be a review of relatively recent developments in analytical methodologies that have enabled dramatic increases in the precision and accuracy of determinations of geologic time. Finally, a series of case studies will illustrate the kinds of geological problems common to the Precambrian for which these developments present the possibility of robust solutions, or at least the testing of hypotheses.