The CREp Chlorine-36 exposure age and depth profile calculator
Résumé
In situ cosmogenic chlorine-36 (36Cl) is so far the only nuclide applicable in carbonate environments and in aphyric Ca-and K-rich silicate rocks. Because the production reactions of 36Cl are more numerous and complex than those of other cosmogenic nuclides (e.g. 10Be, 3He), comprehensive and user-friendly calculators are essential (Schimmelpfennig et al., Quat. Geochr. 4, 441-461, 2009; Marrero et al.,Quat. Geochr. 31, 160-187,2016). However, several drawbacks still affect these commonly used calculators, such as over simplification of the muon production model, which can be inaccurate for depth profile simulations, or the absence of choice regarding production rate parameters. Here, we present a new 36Cl exposure calculator, which we are currently implementing in the existing cosmic-ray-exposure program CREp (crep.otelo.univ-lorraine.fr; Martin et al., Quat. Geochr. 38, 25-49, 2017).So far, CREp allows calculating 10Be and 3He surface exposure ages and provides the possibility to choose between global or locally and regionally calibrated production parameters of these nuclides from the ICE-D-calibration data base. Taking advantage of the most recently developped scaling,muon and low-energy neutron models, the CREp-36Cl calculator allows calculating surface exposure ages as well as depth profiles and provides several choices between scaling and muon models and production parameters.