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Tribal distributions depicted on these maps (and on all other tribal maps covering a comparable area) are arbitrary at many points. Detailed knowledge of tribal areas was acquired at different times in different regions. For example, by the time knowledge was gained of the areas occupied by Plains tribes, many...

Two developments, aerial photography and airborne geophysical surveying techniques, have already increased the rate at which new knowledge of the world's resources can be acquired. But even with far wider use of the tools and techniques already available, the problems that face us are greater than our current ability to...

The present status of research on discrimination of natural and cultivated vegetation using radar imaging systems is sketched. The value of multiple polarization radar in improved discrimination of vegetation types over monoscopic radars is also documented. Possible future use of multi-frequency, multi-polarization radar systems for all weather agricultural survey is...

The statement that a new era in exploration is opening will almost surely bring to mind the venturing of man into space and the ever more imminent exploration of the moon. The reference here, however, is to exploration of earth itself and to the unique capabilities for study of the...

This is the forth in a series of six reports that the U.S. Geological Survey published on the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the March 27, 1964, Magnitude 9.2 Great Alaska Earthquake and extended, as detailed investigations, through several...

Decatur County and several other counties in south-central Iowa comprise an area that has been chronically short of good-quality water.  Municipalities, industries and rural water users alike have been affected by the water shortage.  Municipalities have experienced serious problems in obtaining potable supplies adequate to keep pace with their growth...

Crater Lake National Park, in volcanic terrain at the crest of the southern Cascade Range, is well watered by a 67-inch average annual precipitation, measured at park headquarters. Existing park facilities utilize springs that provide quantities of water adequate for present-day as well as foreseeable future needs. Ground water occurs under...

In late June and July, 1967, the Deep Submergence Research Vehicle (DSRV) ALVIN, aboard its mother snip, LULU, proceeded from the spring base of operations, Nassau, to its home port of Woods Hole. During this trip, from July 2 to July 14, a series of five dives were made by...

The presently available data on streamflow, runoff rainfall, and temperature of Puerto Rico are evaluated, although the period of record is very short, with a view to contributing to the knowledge of hydrology of tropical islands. The average annual streamflow in Puerto Rico is 45 percent of the annual rainfall, or 15 percent more than in the eastern piedmont of...

Devonian rocks along the Yukon River near the Alaska-Yukon boundary comprise 250 feet of limestone and shale and 800 feet of chert and siliceous shale, all referred to the McCann Hill Chert of Early to Late Devonian age; about 3,000 feet of non-marine chert-pebble conglomerate, graywacke, and shale of...

The Sierra Nevada batholith is localized in the axial region of a complex faulted synclinorium that coincides with a downfold in the Mohorovicic discontinuity and in P-wave velocity boundaries within the crust. Observed P-wave velocities are compatible with downward increase in the proportion of diorite, quartz diorite, and calcic granodiorite...

Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is...

Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied...

Foraminifera and Mollusca collected from the phosphatic Pungo River Formation and the overlying Yorktown Formation in eastern North Carolina were analyzed and interpreted for stratigraphic and environmental significance in order to determine optimum depositional sites for primary phosphorite. The Mollusca and benthonic foraminifera of the Pungo River Formation correlate with those of the Calvert Formation...

The Taconic rock sequence extends from near Sudbury, Vermont, to near Poughkeepsie, New York, a length of about 150 miles; and from just west of the Green Mountain Range and Berkshire Highlands to the valleys of the Hudson River and Lake Champlain, a width of about 20 miles. The Taconic rocks are now in...

In August 1965, a scallop dredge from R/V Albatross brought up many pieces of fossiliferous opaline chert or porcellanite of Eocene age from Fippennies Ledge, a bank 70 m deep in the central Gulf of Maine. Their presence in this area supports the idea that part of the Gulf is underlain by sedimentary rocks of Tertiary age. Occurrence in the porcellanite of two...

Hon Trung Lon, a granite island off the coast of South Vietnam, is composed solely of a unique, extremely differentiated, high-silica alkali granite of Cretaceous age. An adjacent island, Hon Trung Nho, is composed solely of rhyolitic rock of similar composition. The Hon Trung Nho rhyolite may be a fine-grained equivalent of the granite. Whole-rock potassium-argon analysis suggests that the age of the Hon Trung Lon granite is greater than 70 m.y. and less than 100 m.y. This age implies a...

Several well-exposed and little-deformed Belt Supergroup sections have been studied in the southern Lewis and Clark Range. In the area studied, the Belt thins eastward or northeastward due both to primary sedimentation and to pre-Middle Cambrian erosion. These rocks can now be more precisely correlated with the well-known sections near Bonner, Helena, and Glacier National Park. In the western part...

Shock effects in quartz, plagioclase, biotite, amphibole, and some accessory minerals have been observed in rocks subjected to various degrees of meta morphism by meteoritic impact. The shock features described are unique; they are never observed in rocks from normal geologic environments. Such features are described:1) Multiple sets...

Some recent examples of transient Earth loads (Lake Bonneville, Utah; Glacier Bay, Alaska; northeast Greenland) indicate that both the viscosity and finite strength of the mantle are lower than is commonly presumed. A time constant (1/e) of 4000 years is estimated for Lake Bonneville, and of 1000 years for...

A klippe of unmetamorphosed Devonian carbonate rocks rests on the Harrison Pass intrusive body south of Toyn Creek in the central Ruby Mountains, Elko County, Nevada. This klippe and other klippen of Carboniferous strata - first mapped by R. P. Sharp (1942) - that rest on lower Paleozoic strata are believed to represent a once-continuous thrust sheet...