At 2:30 a.m. local time on March 27, 1986, Augustine volcano erupted in Cook Inlet, 180 miles southwest of Anchorage, Alaska. The Landsat 5 satellite acquired a Thematic Mapper image of the volcano at 10:46 a.m. Ash falling throughout the area curtailed air traffic, power usage, and business activities. The U.S. Geological Survey monitors Augustine and the 51 other active volcanoes in the United GEOLOGIC INVESTIGATIONS MISSION AND OUTLOOK During fiscal year 1986, the Geologic Division of the U.S. Geological Survey continued its programs to assess energy and mineral resources onshore and offshore, to identify and investigate geologic hazards, and to determine the Nation's geologic framework, the geologic processes that shaped it, and their relation to long-term climatic changes. The articles in this chapter describe some of the most significant accomplishments of the Geologic Division during fiscal year 1986. Although these articles cover only a select few of the Division's activities, they show how basic geologic research simultaneously spurs new developments in the geosciences and provides the basic information required to conduct missions central to the needs of the Nation. MAJOR PROGRAMS The Geologic Division program is presented to Congress under five major program headings. A discussion of accomplishments under these subactivities during fiscal year 1986 and the outlook for the future follow. Geologic Hazards Surveys A regional earthquake hazard assessment in the Provo-Salt Lake City-Ogden area of Utah was conducted in fiscal year 1986. Efforts with State and local officials to ensure that the results of this study are used to implement hazard reduction practices continue. A similar research effort in the be installed and calibrated in fiscal year 1987. (See "Predicting the next major earthquake in the Parkfield area of California," p. 12, for more information.) A study of the effects of recent earthquakes in Mexico and Chile provided data that can be applied to improving knowledge of similar seismic events that may occur in the United States. For example, the study greatly improved understanding of the devastating role that unconsolidated sediments can play in amplifying ground shaking. Fiscal year 1986 was a year of unusual volcanic activity in Alaska and Hawaii (additional information regarding the Alaskan eruptions is found on p. 58). Monitoring and hazard assessments of all volcanically active regions of the Nation. continue. Geologic Division scientists also assisted the Office of Foreign Disaster Assistance of the Agency for International Development during the eruption of Nevado del Ruiz in Colombia. (See "International activities," p. 105, for more information.) Cooperative Federal-State landslide hazards assessment studies were established in fiscal year 1986 with the States of Arizona, Colorado, Idaho, Maine, Nevada, New Mexico, Ohio, Oregon, Utah, and the Commonwealth of Puerto Rico. Probability studies of landslide occurrence in the San Francisco Bay area of California and the Wasatch Front in Utah to identify dominant landslide processes amenable to low-cost landslide hazard reduction and a landslide hazards assessment of the Pittsburgh region of Pennsylvania are also planned. Puget Sound region of Washington State is Land Resource Surveys planned. Installation of instrumentation for the States. (Photograph courtesy of prototype earthquake prediction experiment at Parkfield, Calif., was continued in fiscal year 1986; additional instruments will Earth Observation Satellite Company, Lanham, Md.) A nationwide survey of geoscience information users conducted by the National Research Council indicated that large-scale general-purpose geologic maps are the products most in demand by private and public consumers. In response to this survey, the Geologic Framework and Synthesis Program will be redirected to become the National Geologic Mapping Program. Although most of the basic research functions of the former program will be preserved, its emphasis will be shifted to systematic, prioritized geologic mapping. The Federal-State Cooperative Geologic Mapping component of the Geologic Framework and Synthesis Program will be preserved as an element of the National Geologic Mapping Program. Thirty-one Federal-State cooperative projects were underway in fiscal year 1986. Significant activities under the Deep Continental Studies component of the Geologic Framework and Synthesis Program are addressed in articles on the TransAlaska Crustal Transect and the Salton Sea Scientific Drilling Program (see p. 60, 55). Plans are underway to establish the Deep (see p. 53). Data previously gathered by programs within the Mineral Resource Survey's subactivity have been used to establish a national geochemical data base for identifying and monitoring areas where soil and water are contaminated. The first step in this plan was to compile existing data; areas where insufficient data exist are being identified, and plans are being developed to implement a schedule of sampling and resampling. Fiscal year 1986 saw the acquisition of software to produce digital mineral resource assessment maps compatible with land use, census, and other geographic and water information maps produced in other information systems of the Geological Survey. This compatibility will facilitate comparisons of mineralized locations with other social and economic conditions within a geographic area. Continental Studies component as a separate Energy Resource Surveys program because of its close association with the Continental Lithosphere Program (conducted by the National Science Foundation) and with the Continental Scientific Drilling Program (conducted jointly by the Geological Survey, the U.S. Department of Energy, and the National Science Foundation). Research under the Climate Change Program has established the long-term history of lake-level fluctuations in the United States. The geologic record indicates that historical lake levels are abnormally low and that the trend from natural variation indicates a long-term rise in lake levels. These studies illustrate that basic research can be useful in identifying and resolving environmental policy issues associated with potentially significant economic impacts. Geologic Division scientists continue to be In fiscal year 1986, the Uranium and Thorium Investigations Program began using geologic data to identify areas having high potential for indoor radon hazards. Further information on this effort is contained in this chapter (see p. 38). In cooperation with the Kentucky Geological Survey, a study to characterize the quantity, quality, and accessibility of lowsulfur coal in eastern Kentucky began. Included in that effort are an economic evaluation of the area's potential for coal production and computer modeling of the coal deposits. This type of study may be expanded to include other coal-bearing areas in the Appalachian region. directly involved with the U.S. Army Corps Offshore Geologic Surveys of Engineers and other concerned Federal and State agencies in addressing the hazards created by changing lake levels in areas such as the Great Lakes, including advising those agencies on the feasibility of mitigation strategies. The Coastal Erosion Program, established in fiscal year 1986, is designed to provide geologic information on the nature, extent, and cause of coastal erosion to the various Federal and State agencies that make decisions pertaining to the arrest and (or) mitigation of coastal retreat and land loss. The current focus of the program is the Mineral Resource Surveys highly vulnerable coastal segments of the The National Mineral Resource Assessment Program is described in this chapter Louisiana barrier island system. The results of sonar surveying of the sea floor of the Gulf of Mexico and of submarine Study site Convergent margin Ridge axis Transform fault Boundary of Exclusive Economic Zone ridge and on related volcanic and transform The U.S. Geological Survey began a program in 1980 to study hydrothermal processes associated with massive sulfide mineral deposits on the deep-sea floor. Through 1984, the field studies under this program were primarily concerned with the southern Juan de Fuca Ridge, an area 270 nautical miles west of Newport, Ore. (site A, fig. 1), that lies outside the Exclusive Economic Zone (EEZ) of the United States. The Juan de Fuca Ridge is a 12-mile-long segment of the axis of an oceanic spreading ridge characterized by voluminous young volcanic extrusions related to the growth of ocean crust. The massive sulfide deposits, which were discovered in 1981, occur within a narrow, approximately 100- to 165-footwide linear depression underlain by glassy sheet-flow lavas. The three largest sulfide deposits were examined by using the research submersible Alvin in September 1984, and extensive mineral, hydrothermal fluid, and biologic samples were recovered. Since 1984, researchers at the Pacific Marine Environmental Laboratory of the National Oceanic and Atmospheric Administration (NOAA) have worked closely with the Geological Survey to provide a jointly main- Escanaba Trough tained acoustic transponder positioning net in the Juan de Fuca area. A joint diving program using the Alvin submersible is planned, as is development of a long-term effort to monitor the hydrothermal systems. The focus of the program shifted in 1985 to the Gorda Ridge, which is southeast of the Juan de Fuca Ridge and lies entirely within the U.S. EEZ (fig. 1). Possible hydrothermal sulfide deposits were identified during the late summer of 1985 along the In September 1985, Survey scientists led a research team, including geologists and geophysicists from OSU, that discovered massive sulfide and related petroleum deposits in the Escanaba Trough. After regional geophysical surveying of the Escanaba Trough was completed, two detailed study areas (D and F, fig. 1) were selected. Volcanic domelike intrusions pierce and uplift the 1,640-foot-thick faulted sediment fill of the trough in these two These two study areas were the main sulfide veins, and massive sulfide was recovered in 11 dredges from the two main study areas. Unlike the samples dredged in 1985, most of the fragments recovered are rich in zinc, copper-iron, and lead sulfides, in addition to various iron-sulfide phases. Semiquantitative analyses of these samples. demonstrate that some contain more than 1 percent of both copper and lead and more silver than had been previously reported for deep-sea polymetallic sulfide. Most of the deposits appear to be sediment hosted. the sediment cover in many areas (fig. 2). Northern Gorda Ridge Sulfide deposits were photographically mapped in 1986 at numerous locations in two areas (sites D and F, fig. 1); site F is the same area where sulfide was dredged in 1985. In addition, a gravity core from site E in figure 1 recovered sediment cut by Detailed surveying and sampling along the northern axis of the Gorda Ridge (GR14) (site B, fig. 1) indicated two potential targets for sulfide deposition. The first target is along the eastern wall of the axial valley and coincides with the inferred source of a hydrothermal plume mapped in the water column by NOAA and OSU scientists. The target zone is a ridge between the wall of the axial valley and a broad terrace at a depth of 9,500 feet. On the basis of a water chemistry anomaly, the target is thought to be a zone of active hydrothermal discharge. The second target is in the axial valley, where photographic surveys identified an area of high biologic density, and the rocks |