The Experimental Geophysics Group of the Earth Sciences Department at Lawrence Livermore National Laboratory (LLNL), Livermore, Calif., has experimental equipment that measures a variety of physical properties and phase equilibria and kinetics on rocks and minerals at extremes of pressure (to 500 GPa) and temperature (from 10 to 2800 K). These experimental capabilities are tabulated in this report, and some of the experimental equipment is described in detail.
Experimental geophysics began at the LLNL in the early 1960s as an outgrowth of the Plowshare program, whose purpose was to develop peaceful applications for nuclear explosives. Research activity in rock mechanics expanded rapidly shortly thereafter when underground nuclear testing began. We needed to know the mechanical properties of specific Nevada Test Site rocks at high pressure in order to contain our own texts, and of rocks in general in order to interpret the seismic information emanating from nuclear tests by other countries. Several large testing frames, pressure vessels, and pumping capabilities were acquired at this time. The equipment base left behind by the nuclear test containment and seismic-monitoring programs allowed us to broaden our research horizons, in turn allowing us to further expand our research capabilities. We now pursue a very diverse program of study of the physical and chemical behavior of rocks and minerals under extremes of pressure and temperature for a wide variety of Earth-science applications.