United States Geological Survey YearbookThe Survey, 1987 - Forest reserves |
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Results 1-5 of 75
Page 5
... occurred , and as a result , the proc- ess of continental separation was " frozen into " the crust . Because of these circum- stances , the seismic profiles not only are important in deciphering the geology of the immediate area but ...
... occurred , and as a result , the proc- ess of continental separation was " frozen into " the crust . Because of these circum- stances , the seismic profiles not only are important in deciphering the geology of the immediate area but ...
Page 25
... occurs within an area dominated by Middle Proterozoic anorogenic magmatism , and the ores are hosted by coarse clastic sedimentary rocks , which are interpreted mainly as breccias . Such an ore - forming environment could be present in ...
... occurs within an area dominated by Middle Proterozoic anorogenic magmatism , and the ores are hosted by coarse clastic sedimentary rocks , which are interpreted mainly as breccias . Such an ore - forming environment could be present in ...
Page 27
... occur repetitively as part of sedimentary cycles that are con- trolled , in part , by climatic variation . Four metal - enriched horizons have been identi- fied from one locality in the Culpeper basin . Epithermal base - metal and ...
... occur repetitively as part of sedimentary cycles that are con- trolled , in part , by climatic variation . Four metal - enriched horizons have been identi- fied from one locality in the Culpeper basin . Epithermal base - metal and ...
Page 29
... occur at the part per billion to part per million level . Preliminary eval- uation of a limited data set indicates corre- lations between the trace elements and platinum - group elements . In addition to providing the data required for ...
... occur at the part per billion to part per million level . Preliminary eval- uation of a limited data set indicates corre- lations between the trace elements and platinum - group elements . In addition to providing the data required for ...
Page 33
... occur in deposits that are uneco- nomic to recover or in less well - known extensions of identified deposits . Addi- tional minor or less well - known deposits have been discovered in several countries including Australia , Brazil ...
... occur in deposits that are uneco- nomic to recover or in less well - known extensions of identified deposits . Addi- tional minor or less well - known deposits have been discovered in several countries including Australia , Brazil ...
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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