Inclined layer-silicate microstructures and their use as a sense-of-slip indicator for brittle fault zones

Abstract

This Short Note introduces a new microscale sense-of-slip indicator for brittle fault zones. The microstructure is developed within laminated quartz veins and consists of fault-parallel bands of layer-silicate minerals with their long axes and (001) planes consistently inclined in the transport direction. Like other microscale sense-of-slip indicators, this microstructure may prove most useful in situations where mesoscale criteria are either lacking or poorly developed. Because of its intimate association with fault-zone vein material, this microstructure may also help in deciphering the motion history of reactivated faults.