Research

At many plate boundaries, particularly those that involve continental crust, relative plate motions are accommodated over a broad region with many faults that can interact and evolve in complex ways. Understanding this behaviour and what controls it is essential for understanding past and present deformational processes, and allows us to more confidently assess the seismic hazards associated with modern plate boundaries.

The long-term behaviour of the global plate system, reconstructed principally from paleomagnetic data, is an essential control on the Earth’s geological, climatic and biological evolution. Understanding the fundamental controls on plate motions also provides key insights into the processes that drive the formation of mountains belts and the opening of oceans over geological time

Understanding the source of paleomagnetic and rock magnetic signals recorded in sedimentary and igneous rocks is what makes good data into meaningful data. Because most commonly occurring magnetic minerals are very sensitive to changes in redox conditions, it is particularly important to understand how diagenetic alteration can affect tectonic and environmental magnetic signals, so that they can be correctly interpreted.

Several hundred feet of rock salt (halite and anhydrite) in the Upper Silurian Salina Group has been a significant influence on the structural and tectonic development of the region, acting as a major décollement for intense thin-skinned thrusting during the building of the Appalachian Mountains. Graduate student Matt Harding is investigating possible connections between large, regional basement faults and the development of décollement thrusting in the overlying Salina Group, through analysis of 3D seismic data and analogue modelling.

The modern East Pacific Rise is the largest remaining remanent of the Pacific-Farallon Ridge (PFR), which during the Late Cretaceous extended more than 10,000 km across the entire Pacific basin; this fast-spreading ridge system has produced as much as 45% of all the reconstructable oceanic lithosphere created by the global ocean ridge system since 83 Ma. In collaboration with David Rowley at the University of Chicago, Chris Rowan is working on improved reconstructions of the past spreading history of the PFR and the controls on its tectonic evolution, particularly the apparent strong dynamic link with a long-lived buoyant upwelling from the core mantle boundary.