corresponding to those of the core-mantle boundary in large samples. In situ measurements on samples of a cubic millimeter or more at temperatures of 6000°C and pressures up to 1,000 kb (100 GPa) would go a long way toward solving some of the mysteries of this fascinating region of the Earth. Development of this type of equipment will require new superhard materials in innovative configurations.
In addition to the development of super-high-pressure equipment, there is a need for a new generation of instruments capable of generating triaxial stresses for carrying out brittle and plastic deformation experiments under controlled conditions up to 50 kb (5 GPa) and 1500°C. The volume of the pressure vessel's interior should be large enough to contain pressure and internal force cells and to control the chemical environment of fluid solutions.
With regard to the study of samples at high pressures and temperatures, intense, highly collimated synchrotron x-ray sources provide earth scientists with an extraordinary new technique. X-ray diffraction, fluorescence, and absorption studies can now be carried out on microsamples. There is intense competition for beam time at existing synchrotron facilities, but opportunities do exist for earth scientists to participate in the design and operation of new beam lines at the National Synchrotron Light Source at Brookhaven, the Cornell High-Energy Synchrotron Source, and the Stanford Synchrotron Research Laboratory. It is very important that they continue to do so. In addition, a new major facility is being planned at Argonne National Laboratory—the Advanced Photon Source (APS), which will provide radiation several orders of magnitude more intense than present sources. The earth science community needs to participate in the development of the APS beam lines so that they are designed to meet the needs of the earth materials research community.
The practice of the earth sciences requires the analysis of information from many different sources. Questions about this information include:
Is adequate information available to the earth science community to provide informed answers?
In what forms is this information available?
How is access to the information obtained?
Is the information being refined and augmented?
What resources are applied to obtaining and updating the information, both in general and for specific investigations?
Who is responsible for obtaining, archiving, updating, and providing interpretations of this information?
Not surprisingly, there are no complete answers to these questions, because different kinds of information are handled in different ways. It is, however, quite possible to provide partial answers to the questions, to identify present successes, and to point out potential courses of action.
Enormous amounts of information are available to the earth scientist attempting to understand geology, resources, environment, and hazard potential. For example, topographic map coverage for the land surface and offshore areas of the Exclusive Economic Zone is both detailed and up to date. Maps are the traditional and useful format for presenting earth science information; geological maps and many more specialized kinds of maps are available. Basic information of this kind is handled on the national scale by federal agencies—the U.S. Geological Survey (USGS) in the case of surface topography and the National Oceanic and Atmospheric Administration (NOAA). This is also the case for much other important information.
At the state level, the geological and more specialized maps and publications of the state geological surveys represent a body of information complementary to that of the federal agencies. To compare the scale of operations, it is useful to observe that expenditures by the Geologic Division of the USGS in a recent year were about $200 million, while expenditures for all the state geological surveys together were about $133 million.
National (and international) professional societies, especially the Geological Society of America, the American Association of Petroleum Geologists, the Society of Economic Geologists, and the American Geophysical Union, as well as many local and regional societies, publish a significant proportion of the essential information available about the geology of the United States. An achievement currently nearing completion is publication by the Geological Society of America of a unique up-to-date series of assessments of the geology and regional geophysics of the North American continent and its neighboring oceans— The Decade of North American Geology. Field guides covering much of the country, prepared on the occasion of the 1989 International Geological Congress in Washington, D.C., represent another recent achievement. Field