Dating methods: Geochronology and landscape evelution

Two exciting areas of research are highlighted in this summary of recent publications in the field of geochronology. These lie at opposite ends of the timescale that is normally of interest to geomorphologists, but both have a common interest since they make it possible to quantify rates of landscape evolution in ways which have been difficult, if not impossible, previously. The first area concerns the developments that have occurred in the use of cosmogenic isotopes, and particularly their use over periods from 10⁴ to 10⁷ years, while the second looks at two absolute dating techniques that are now available for quantifying geomorphological processes within the last 103 years. This is a time interval for which absolute dating control has proved problematic for many years, since it lies beyond the range of many historical data sources and aerial photo coverage, and beyond the limit of ²¹⁰Pb or ¹³⁷Cs measurements. Over this time period radiocarbon results are significantly affected by reservoir effects and fluctuations in production rates.