Graham Weedon is Senior Lecturer in Geology at the University of Luton. His current research involves studying records of annual cycles in cave calcite, ENSO cycles in varved sediment and Milankovitch cycles in ancient deep-sea sediments. He received a D.Phil from Oxford University in 1987, and has participated in Ocean Drilling Program cruises, off Oman (1987), Brazil (1994) and New Zealand (1998). In 1999 he co-convened a Royal Society Meeting entitled 'Astronomical Calibration of the Geological Time Scale'.