9304033 Weidner This is a project to examine the phase equilibria for the olivine system at the pressures and temperatures of the 400 km discontinuity. The experiments will be carried out with SAM-85, a cubic anvil high pressure system used in conjunction with the NSLS synchrotron. The major advantage of this system is that the pressure in the sample cell is continuously monitored. This is essential to directly associate a seismic discontinuity at depth in the earth with a phase transition observed in the lab where the pressure scale may be precise but inaccurate. ***
