Public Lecture by Jeffrey Vervoort

Unravelling the Early History of the Earth

A public lecture by Professor Jeffrey Vervoort, Professor of Isotope Geochemistry, Washington State University and 2018 UWA Robert and Maude Gledden Senior Visiting Fellow.

Earth scientists have long been interested in the nature of Earth’s earliest continents. There are several fundamental and outstanding questions concerning the formation and evolution of planet Earth: How and when did Earth’s earliest continental crust form? What was the composition of this crust and was there a change in its composition through time? What was the volume of this early-formed crust—was it once extensive and subsequently destroyed or did it not exist in any volume until later in Earth’s history? The oldest crystalline basement rocks preserved in small regions on many of the continents are some of the most important sources of information into Earth’s earliest history. But these rocks provide an incomplete and complicated history. There are only scattered rocks from the first billion years of Earth’s history—older than 3.5 Ga (Giga annum = billion years), a much smaller portion are older than 3.8 Ga, and there are no intact rocks older than 4.0 Ga. In addition, these oldest rocks are often complicated mixtures containing different ages and components making their interpretation challenging. Two of the major tools that we use to answer these questions are geochronology and isotope geochemistry. Geochronology provides constraints on the ages of rocks; radiogenic isotopes provide tracer information that allows us to understand the origin of these rocks and their prehistory in the early evolving Earth. Using the best-constrained data from these methods, we suggest that continental crust did not start forming—and was not preserved—in significant volumes until ~3.5 Ga, similar to what we see preserved in the geological record today.

Professor Vervoort is a leading expert in radiogenic isotope geochemistry and geochronology and has been among the pioneers in applying these tools to understanding the early Earth. Dr Vervoort received his PhD from Cornell University in 1994 and was a research scientist at the University of Arizona for several years before joining the faculty of Geology at Washington State University in 2002. He rose to the rank of full professor in 2013 and is currently director of the Radiogenic Isotope and Geochronology Laboratory (RIGL) at Washington State University. Professor Vervoort has published over 140 peer-reviewed papers spanning a wide range of topics in isotope geochemistry. These papers have been cited over 11,000 times with an H-index of 47 (Google Scholar). He is a Fellow of the American Geophysical Union and the Geological Society of America and has held over 20 research grants from the US National Science Foundation.

Professor Vervoort will be in residence at The University of Western Australia through mid May as a UWA Robert and Maude Gledden Senior Visiting Fellow.