Most of those who use this volume of the Geological Survey ResearchSeries will come to it primarily to learn about the progress of research in a particular field, or in a group of fields that are closely related. The Geological Survey Research series serves another purpose also an overview of earth sciences research in progress in the USGS and an indication of the emphasis being given to individual subjects. Few will have the interest or stamina to read Geological Survey Research 1977 from cover to cover, but a few minutes spent on the table of contents will be sufficient to identify the areas that are receiving increased attention.Because the USGS is a mission-oriented, public service organization, its work responds to the Federal government's perception of public needs. These needs for information about the Earth and its resources and for knowledge of geologic processes and history have been broadening and deepening in recent years in the United States, which has led in turn to expanded investigations in many fields such as the Outer Continental Shelf, earthquake hazards reduction, geothermal energy, river-quality assessment, and water use, to name only a few of them in which little or no research was underway only a decade ago.These trends toward expanded and broadened earth sciences research and factfinding are bound to continue as problems of resource adequacy, environmental quality, and safe use of the land become more complex and difficult, and more critical to the National Welfare.