Welcome to SHED Earth. SHED refers to Schmidt Hammer Exposure Dating: a technique that provides a cost-effective solution for dating the exposure of granite surfaces. This can be used to constrain the timing of past events, which permits a better understanding of the links between climate and landscape evolution.
The approach is based upon a study by Tomkins et al. (2016)1, in which a statistically significant relationship was observed between the exposure ages (derived from terrestrial cosmogenic nuclide dating), and Schmidt Hammer rebound values (R-values) of 25 granitic surfaces from NW England and Scotland. This has recently been updated with 29 additional exposure ages from across Scotland and Ireland2 and is now applicable over the timescale 0.8 - 23.8 thousand years ago, covering the entire post-Last Glacial Maximum (LGM) history of the British-Irish Ice Sheet. In addition, a new curve has recently been made available for the Pyrenees18, based on 52 TCN dated surfaces from across the mountain range. These new data confirm the accuracy and reproducibility of previous research1 and demonstrate that this method can be applied successfully in contrasting climatic regimes. In addition, these studies show that equivalent time-dependent weathering of granite surfaces can occur over significant spatial scales for regions of similar climate. The technique has been demonstrated to be of comparable accuracy and precision to ages derived from TCN dating, but without the significant expense that goes along with the use of such techniques, making it useful for researchers and students alike.