Climate and Global Change Atmospheric and Environmental Chemistry Dynamics of the Atmosphere and Other Geophysial Fluids The Paleogeographic Atlas Project High Pressure Geophysics Geochemistry and Cosmochemistry Igneous and Metamorphic Petrology Paleontology and Evolution Other Departments and Related Institutions Affiliated Centers

The physical properties of rocks and fluids change dramatically over the 3.6 megabar pressure range of the Earth. To relate seismological data to physical and chemical models of the Earth requires careful measurements of mineral equations of state and phase equilibria. The generation of high-pressure melts, and the evolution of an initially molten Earth, depend equally on the high pressure properties of molten silicates. In the Department of the Geophysical Sciences we currently use four basic techniques to explore the effects of high pressure

The pressure range of the crust and uppermost mantle is accessible via several piston-cylinder presses. These large volume experiments are used to characterize mineral and mineral-fluid equilibrium in a variety of systems.

Diamond anvil cells reach pressures near a megabar, and with laser heating can have simultaneous temperatures as high as 3000K. An in-house rotating anode X-ray source is used to determine crystal structures at high pressure and mineral equations of state. Synchrotron sources at Brookhaven National Laboratory and the CARS beamlines at Argonne National Laboratory facilitate more elaborate X-ray measurements at higher speed and with smaller samples.

Relevant Faculty include:

• Consortium for Advanced Radiation Sources
• Bruce Buffett, Geodynamics
• Dion L. Heinz, High Pressure Geophysics
• Robert C. Newton, High Pressure and Metamorphic Petrology (retired)