United States Geological Survey YearbookThe Survey, 1987 - Forest reserves |
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Results 1-5 of 53
Page 4
... caused by differing magnetic properties in rocks beneath the aircraft . An area is mapped as the plane flies a series of parallel traverses and the plane's location and the measured magnetic field are recorded on magnetic tape . Later ...
... caused by differing magnetic properties in rocks beneath the aircraft . An area is mapped as the plane flies a series of parallel traverses and the plane's location and the measured magnetic field are recorded on magnetic tape . Later ...
Page 5
... caused total separa- tion of the continent on either side of the rift and the formation of an ocean basin like the present - day Atlantic Ocean . For rea- sons not yet fully understood , the rifting stopped before complete continental ...
... caused total separa- tion of the continent on either side of the rift and the formation of an ocean basin like the present - day Atlantic Ocean . For rea- sons not yet fully understood , the rifting stopped before complete continental ...
Page 6
... caused by basalt flows and interlayered sedimentary rocks within the graben . Weaker but still promi- nent reflections are caused by sedimentary rocks . The prerift Archean rocks are largely trans- parent , producing strong reflec ...
... caused by basalt flows and interlayered sedimentary rocks within the graben . Weaker but still promi- nent reflections are caused by sedimentary rocks . The prerift Archean rocks are largely trans- parent , producing strong reflec ...
Page 16
... caused degradation in the quality of surface waters in some basins to the extent that careful monitoring will be required to prevent fur- ther degradation of these waters to the point where they fail to meet water - quality criteria ...
... caused degradation in the quality of surface waters in some basins to the extent that careful monitoring will be required to prevent fur- ther degradation of these waters to the point where they fail to meet water - quality criteria ...
Page 29
... causes the fault to lock , preventing motion and pro- ducing a buildup of stresses . When the accumulating stress exceeds the strength of the rocks bounding the fault , the rocks suddenly slip . This slipping action allows the surface ...
... causes the fault to lock , preventing motion and pro- ducing a buildup of stresses . When the accumulating stress exceeds the strength of the rocks bounding the fault , the rocks suddenly slip . This slipping action allows the surface ...
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activities Administration Alaska analysis aquifer areas Award basin Board Bureau Calcasieu River cartographic cartographic data Chief Hydrologist City City of w climate coal coastal Commission concentrations contamination cooperative Coordination County data base Denver Denver Federal Center Department of Public deposits Earth Science earthquake energy environment Environmental fiscal flow geographic information systems Geologic Division geologic map Geologist geophysical global change gram graphic ground water ground-water hazards hydrologic Hydrologist investigations Irrigation Lake Lake Nyos land located Management ment miles mineral resources National Center National Mapping Division natural Office organic Park percent Planning processes radon Regional Reston River rocks samples San Joaquin River scientific scientists sediment seismic selenium Service soils Stop streamflow studies surface tion Transportation U.S. Geological Survey United users USGS Valley Volcano Water Conservation District Water District water quality Water Resources water-quality wetlands zone