Developing and designing new applications of the analytical methods of Fission Track Analysis and U-Th/He Analysis of accessory minerals to constrain tectonic and geomorphic processes. Specific areas of interest include applications to understanding long-term landscape evolution, determining erosion rates and sediment yields over geological time scales and understanding the role of tectonics, climate and eustasy in controling rates of long-term landscape change.
Terrestrial Cosmogenic Nuclides
Developing methods and strategies for integrating in-situ produced cosmogenic nuclide abundance measurements on surface mineral samples with low-temperature thermochronologic data to constrain rates of landscape forming processes over geologically relevant time scales.
Geodynamics & Landscape Evolution
Investigating the coupling between deep Earth processes (like mantle convection) and the generation and evolution of large scale topography.
Remote Sensing & Digital Geoscience
Developing new strategies and methods for using high resolution satellite derived data sets (such as multi & hyperspectral surface reflectance data and digital elevation data) to measure and visualise the Earth’s surface topography with the aim of improving understanding of the processes responsible for controlling its morphology and evolution.
Present: Professor of Earth Sciences (Geography)
Active research projects:
Resolving the age of the first order topography of Africa
This project is funded by the Natural Environment Research Council (NERC) for 2010-2013.
Objectives: The primary objective of this project is to test the following hypothesis;
Hypothesis: The first-order topography of Africa is younger than 30 million years old, which will resolve a long standing debate concerning the origin and age of the first-order topography of Africa. The resulting data will also provide detailed information relevant to the discussion concerning how large passive continental margin escarpments form by providing detailed quantitative estimates of the pattern and amount of erosion across the continental margin.
This objective will be achieved by;
1) Determining a high quality suite of AFT and AHe ages from 6 deep bore holes augmented by surface samples (total of c. 105 AFT and AHe analyses).
2) Determining robust, quantitative constraints on the timing, rate and magnitude of erosion that created the present escarpment in southern Africa by using a new technique enabling the joint inversion of both the AFT and AHe data to simultaneously obtain the thermal history and an estimate of the palaeothermal-gradient from a complete suite of bore hole samples.
Wildman, M., Brown, R., Beucher, R., Persano, C., Stuart, F., Gallagher, K., Schwanethal, J., and Carter, A. (2016) The chronology and tectonic style of landscape evolution along the elevated Atlantic continental margin of South Africa resolved by joint apatite fission track and (U-Th-Sm)/He thermochronology. Tectonics, (doi:10.1002/2015TC004042) (Early Online Publication)
Wildman, M., Brown, R., Watkins, R., Carter, A., Gleadow, A., and Summerfield, M. (2015) Post break-up tectonic inversion across the southwestern cape of South Africa: new insights from apatite and zircon fission track thermochronometry. Tectonophysics, 654, pp. 30-55. (doi:10.1016/j.tecto.2015.04.012)
Brown, R., Summerfield, M., Gleadow, A., Gallagher, K., Carter, A., Beucher, R., and Wildman, M. (2014) Intracontinental deformation in southern Africa during the late Cretaceous. Journal of African Earth Sciences, 100, pp. 20-41. (doi:10.1016/j.jafrearsci.2014.05.014)
Chang, J., Brown, R. W., Yuan, W., Li, W., Que, Y., and Qiu, N. (2014) Mesozoic cooling history of the ‘Bachu uplift’ in the Tarim Basin, China: constraints from zircon fission-track thermochronology. Radiation Measurements, 67, pp. 5-14. (doi:10.1016/j.radmeas.2014.05.019)
Brown, R.W., Beucher, R., Roper, S., Persano, C., Stuart, F., and Fitzgerald, P. (2013) Natural age dispersion arising from the analysis of broken crystals, part I. Theoretical basis and implications for the apatite (U-Th)/He thermochronometer. Geochimica et Cosmochimica Acta, 122, pp. 478-497. (doi:10.1016/j.gca.2013.05.041)