Age2exhume - A Matlab/Python script to calculate exhumation rates from thermochronometric ages, with application to the Himalaya, New Zealand, and Central Asia

Thermochronology is one of the most versatile tools available to geoscientists to constrain the colling and exhumation history of rocks. In tectonically active mountain belts around the world, it is not unusual to have many hundreds, if not thousands of published ages available from various studies. Although several well-established thermal models allow for a detailed exploration of how cooling or exhumation rates evolved in a limited area or along a transect, integrating large, regional datasets into such models remains a major challenge. Here, we present age2exhume, a thermal model in the form of a Matlab or Python script, which can be used to rapidly obtain a synoptic overview of exhumation rates from large, regional thermochronometric datasets. The model incorporates surface temperature based on a defined lapse rate and a local topographic relief correction that is dependent on the thermochronometric system of interest. Other inputs include sample cooling age, uncertainty, and an initial (unperturbed) geothermal gradient. The model is simplified in that it assumes steady, vertical rock-uplift and unchanging topography when calculating exhumation rates. For this reason, it does not replace more powerful and versatile thermal-kinematic models, but it has the advantage of simple implementation and rapidly calculated results. In our example datasets, we show exhumation rates calculated from 1785 cooling ages from the Himalaya, 1587 cooling ages from New Zealand, and 916 cooling ages from Central Asia (Tian Shan and Pamir). Despite the synoptic nature of the results, they reflect known segmentation patterns and changing exhumation rates in areas that have undergone structural reorganization. These regionally estimated exhumation rates have been used in combination with other datasets to assess regional climatic versus tectonic controls on key aspects of the landscape, including river valley width and modern erosion patterns.