A method for quantifying the time of cooling in thermochronometric inversions

Abstract. Reconstructing geological processes and events from thermochronometric data typically requires the interpretation of time-temperature path ensembles calculated by inverse methods. Commonly, this may be as simple as associating heating or cooling in thermal histories with specific geologic events and indirectly "dating" such events by estimating the time of observed heating or cooling. While visual assessments may suffice in the simplest cases, statistical comparison requires quantitative estimations of the time of cooling. This study presents a straightforward methodology wherein we ascertain the time of peak cooling for the entire cooling signal within a thermal history model. The focus is on the time-temperature paths intersecting the half-maximum cooling isotherm, where the full distribution of interpolated model times at that isotherm provides a quantitative metric for the characteristic "time of cooling". We apply this method to thermochronologic inversions of synthetic and natural examples, demonstrating its practicality and functionality. This systematic approach provides an effective means of quantitatively reporting the peak cooling time from thermal history inversions.