9805138 Magloughlin Dating movement on specific faults is a pervasively important datum in many geologic investigations, however such information most commonly be obtained indirectly. This problem is particularly difficult in the brittle field as a few isotopic-based systems are active. This proposal tackles dating of brittle faults that produce a transient, fault-generated friction melt. The idea is to determine a methodology to obtain an 40Ar/39Ar age from pseudotachylite that avoids many of the potential errors (inclusion of un-melted source material, inequilbrium in melt and recoil loss effects during analysis, among others). If successful, such a protocol would have broad utility in projects requiring knowledge of the timing of brittle fault movements.
