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The homonyn Navicula rotunda Andrews is replaced by the name N. rotundella Andrews; the homonym Epithemia irregularis Andrews is replaced by the name E. emarginata Andrews. The diatoms are from Trempealeau Valley, Wisconsin (Andrews, 1966)....

The forest of a small watershed-ecosystem was cut in order to determine the effects of removal of vegetation on nutrient cycles. Relative to undisturbed ecosystems, the cut ecosystem exhibited accelerated loss of nutrients: nitrogen lost during the first year after cutting was equivalent to the amount annually turned over in...

Hydration of obsidian has been used to date rhyolite flows, containing obsidian or porphyritic glass, at Glass Mountain (Medicine Lake Highlands) and Mono Lake, California. The method is simple and rapid and can be used to date flows that erupted between 200 and approximately 200,000 years ago....

None of the expected stratigraphic and structural effects of a spreading sea floor have been imposed on the sedimentary fill of the Peru-Chile Trench. During at least the last several million years, and perhaps during much of the Cenozoic, the trench has not been affected by an oceanic crust thrusting...

Diatremes in the Missouri River Breaks demonstrate systematic subsidence-ring structure, contain inclusions derived from far above and far below, and have been produced by gas-rich eruptions of alkalic ultramafic magmas. Similar magmas have produced diatremes in many localities in the world and are known to be closely associated with and...

Alkali amphiboles from Type III and Type IV metamorphic zones in blueschist facies rocks of Cazadero, California, and from comparable New Caledonian rocks have been characterized by X-ray crystallographic, optical, and chemical methods. The composition of any particular alkali amphibole is strongly controlled by the bulk composition of the host...

The artesian basin of the Dakotas has been studied for many years. The widely held concept has been that recharge enters the equivalents of the Dakota Sandstone, where they are exposed on the flanks of the Black Hills, and moves through this formation to the area of maximum development of the aquifer in eastern North Dakota and South Dakota. Some anomalies, difficult...

The purpose of this work is a theoretical consideration of equilibrium conditions in the system nepheline-alkali feldspar-plagioclase-alkali chloride aqueous solution based on the thermodynamic treatment of experimental data (Orville, 1963; Iiyama et al., 1963; Debron et al., 1961) for particular systems. The excess thermodynamic functions (ZE, SE, HE, VE) of solid solutions were calculated for it. These data...

Silicic volcanic rocks — dacite, rhyolite, and quartz porphyry — constitute about 35 percent of the Yavapai Supergroup, an older Precambrian sequence in central Arizona. In addition, the series contains about 30 percent pillow and amygdaloidal basalt, 5 percent andesitic rocks, and the remainder is mixed andesitic and silicic-bedded tuffaceous...

Geologic mapping, paleomagnetic stratigraphy, and potassium-argon dating were used to determine the time and volume relations of tholeiitic and alkalic basalt on Nunivak Island in the Bering Sea near the coast of Alaska. Volcanism on Nunivak Island occurred in distinct episodes separated by quiet intervals that lasted from 1.6 to...

The Southern Coulee is the southernmost and largest of the four Recent pumiceous rhyolitic coulees, or stubby flows, of the Mono Craters, eastern California. It is one of the youngest volcanic deposits of the Mono Craters and is largely bare and uneroded. The coulee is 3.6 km long and averages...

No abstract available....

An outstanding flood occurred in the Wapsinonoc Creek basin in east-central Iowa on June 7, 1967. The flood was the result of rainfall totaling from 4 to 13 inches in about 14 hours on the night of June 6 and the morning of June 7. The storm was nearly centered...

The rapid growth of suburban St. Louis presents problems in the economic development of flood plains within the area. The U.S. Geological Survey in cooperation with the Metropolitan St. Louis Sewer District has a project to study the hydrology of five major drainage basins within the area of responsibility of...

No abstract available....

Prior to the Surveyor missions, there were three principal theories about the chemical constitution of the lunar maria: that the maria were (1) chondritic, (2) basaltic, or (3) silicic. Three types of materials recovered on Earth were suspected of coming from the maria: (1) chondritic meteorites, (2) basaltic achondrites, and...

The surface-water records for the 1967 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The quality-of-water investigations of the U.S. Geological Survey are...

In 1966 more than 50 billion gallons of water was pumped daily from an estimated 10 to 15 million water wells in the United States. This was more than one‐sixth of the national withdrawal of water. On the basis of past rates of increase, a much greater future use of ground water is suggested. Our annual investment in water wells is one‐half to three‐quarter...

An aeromagnetic survey extending from the Gulf of Maine to the tip of Florida was conducted by the U. S. Naval Oceanographic Office between 1964 and 1966. Flight traverses were flown in a northwesterly direction at right angles to the geologic grain. The flight lines were approximately 800 km long and had an 8-km...

No abstract available....

No abstract available....

The K-Ar age of the basal basalt flow at the bottom of the "Lower Canyon group" of lavas near Toroweap fault is 1.16 ± 0.18 standard deviation (sd) m.y. This represents a minimum age of Grand Canyon, for at the time the lava formed, the canyon was essentially as deep as it is today. Since that time the Colorado River has cut through...

A northerly-trending group of quartz diorite stocks that cut Cretaceous, Eocene, 01igocene(?) and Pleistocene( ?) sedimentary rocks near Saindak, West Pakistan, contain oxidized disseminated copper minerals which may occur in commercial concentrations at depth. The stocks are enclosed by an aureole of albite-epidote hornfels about 4 miles wide that locally is cut by veins...

This report is an areal study of a portion of the south coast of Puerto Rico. It follows similar studies of the Guanica, Guayanilla-Yauco, Tallaboa Valley, and Ponce areas to the west and the Jobos area to the east. It basically is an inventory of the water resources during one...

No abstract available....