9303351 Spetzler The recent development in the PI's laboratory of a GHz ultrasonic interferometer with moderate pressure and temperature capabilities (600 MPa and 400K) opens new possibilities for elastic parameter measurements. Because of the inherently high precision of the technique and because of the high frequency, elastic parameters and their pressure and temperature derivatives can be determined for many new minerals and their high pressure phases for which only small (sub millimeter) samples are available. Measure- ments will be made on the pyrope-almandine-grossular solid solution series. This garnet suite represents a very important mantle constituent in the major mantle mineralogy models. ***
