Syntectonic crystal fibres generally contain fluid inclusions with a solid phase (halite crystal, for example), liquid phase (water) and gas. One might carry out studies such as freezing, melting and decrepitation temperatures by study of these inclusions using a heating stage and this study reveals the thermal history of a deformative phase if the fibre has a range of inclusions that give a range of temperatures, since it is known as which the early grown and lately grown parts of a crystal are. Durney did this kind of study for Morcleas nappe in Valais area, Switzerland. The results of his study are briefly summarised in Ramsay and Huber 1983.