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Browse more than 160,000 publications authored by our scientists over the past 100+ year history of the USGS.  Publications available are: USGS-authored journal articles, series reports, book chapters, other government publications, and more.

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Reflecting curved-crystal X-ray spectrograph; a device for the analysis of small mineral samples

A curved-crystal reflecting spectrometer of the type described by Birks and Brooks of the Naval Research Laboratories, but adapted for use in mineralogical studies, has been built in the Geological Survey. It has been successfully applied to the analysis of tiny crystals, zones in minerals, and individual grains in mixed-mineral specimens such as thin or polished sections, on grains or areas about

Discussion of “Some factors affecting rates of sedimentation in the Columbia River basin”

hydrologists are generally aware of the number and complexity of the variables that are encountered in all aspects of hydrology, and the great difficulty of analyzing these factors quantitatively because of inadequacy of basic data. Because of limitations in funds, time, or scientific manpower, it is likely that the basic data will generally be less than the hydrologist's hopes. In this predicamen

The deuterium blance of Lake Maracaibo

A balance sheet for the gains and losses of deuterium from Lake Maracaibo, using estimates based on climatological data for the exchanges of water and measurements of the deuterium content of lake water, rainfall, river flow, and Caribbean Sea water to obtain the volumes of the deuterium exchange, indicates that the relations are qualitatively satisfactory, although not numerically exact.

Comparison of radiogenic helium and lead in zircon

A direct comparison of helium and radiogenic lead in nonmetamict zircon crystals has indicated a 25 per cent discrepancy between these radiogenic constituents. It appears that the amount of helium is only three-quarters of the amount that should be present according to the content of radiogenic lead. Approximately the same proportion was found in zircon having a wide range in age, activity, and to

Direct radiometric measurement by gamma-ray scintillation spectrometer: Part I: Uranium And Thorium Series In Equilibrium 

Where uranium and thorium are in secular equilibrium with their decay products, these elements may be determined by this direct radiometric method if the materials show more than 0.01 per cent equivalent uranium. This method is based on the measurement in a scintillation spectrometer of the relative amplitude of the response from the 238 kev gamma ray from Pb212. Tests on known samples containing

Direct radiometric measurement by gamma-ray scintillation Spectrometer: Part II: Uranium, Thorium, and Potassium in Common Rocks 

The method described in Part I of this report has been extended to the measurement of the uranium and thorium series and potassium in common rocks, or materials of comparable activity, in which the series are in secular equilibrium. The counting rate in an additional band centered on the photopeak from the 1.46 Mev gamma ray of K40 permits the measurement of potassium and the removal of the counts

Regional gravity survey in northeastern Oklahoma and southeastern Kansas

In 1948 the U. S. Geological Survey, in cooperation with the U. S. Coast and Geodetic Survey, made a regional gravity survey in northeastern Oklahoma and southeastern Kansas in connection with the studies of the deflection of the vertical. About 550 gravity stations were occupied with spacings of 5 to 10 miles in parts of 54 counties, and a Bouguer anomaly map, contoured at intervals of 5 milligal

Factors controlling the concentrations of thirteen rare metals in sea-water

The following factors controlling the concentrations of thirteen metals (Zn, Cu, Pb, Bi, Cd, Ni, Co, Hg, Ag, Cr, Mo, W, V) in sea-water were studied:1. precipitation of insoluble compounds with ions normally present in aerated sea-water,2. precipitation of sulphides locally in reducing environments,3. adsorption by ferrous sulphide, hydrated ferric oxide, hydrated manganese dioxide, apatite, clay,

The progressive lag of sediment concentration with flood waves

Numerous investigations of suspended‐sediment discharge have shown that an increase in stream flow usually is accompanied by an increase in sediment concentration. The sediment‐concentration peak during a rise may precede, coincide with, or follow the water‐discharge peak. Observations on the Bighorn River in Wyoming and Montana show a progressive lag in peak concentration behind peak flow. The la

A preliminary report on model studies of magnetic anomalies of three-dimensional bodies

Model experiments were made to devise a rapid method for calculating magnetic anomalies of three-dimensional structures. The magnetic fields of the models were determined using the equipment at the Naval Ordnance Laboratory, White Oaks, Md. An irregularly shaped mass was approximated by an array of prismatic rectangular slabs of constant thickness and varying horizontal dimensions. Contoured maps