Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

184812 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 6913, results 172801 - 172825

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
Abundance and distribution of uranium and thorium in zircon, sphene, apatite, epidote, and monazite in granitic rocks
Patrick M. Hurley, Harold W. Fairbairn
1956, Trace Elements Investigations 636
Analyses were made of uranium and thorium in ziircon, sphene, apatite, epidote, and monazite separated as accessory minerals from samples of granitic rock from widely scattered localities to indicate the abundance and distribution of these two elements among the five mineral phases.  For any pair of mineral phases the distribution...
The determination of uranium (IV) in apatite
Roy S. Clarke Jr., Zalman S. Altschuler
1956, Trace Elements Investigations 637
Geologic and mineralogic evidence indicate that the uranium present in apatite may proxy for calcium in the mineral structure as U(IV). An experimental investigation was conducted and chemical evidence was obtained that establishes the presence of U(IV) in apatite. The following analytical procedure was developed for the determination of U(IV). Carbonate-fluorapatite...
Occurrence of selenium in sulfides from some sedimentary rocks of the western United States
Robert G. Coleman, Maryse Delevaux
1956, Trace Elements Investigations 632
Investigations of the minor- and trace-element content of sulfides associated with uranium ore deposits from sandstone-type deposits have shown that selenium commonly substitutes for sulfur. The Morrison formation and Entrada sandstone of Jurassic age and the Wind River formation of Eocene age seem to be seleniferous stratigraphic zones; sulfides deposited...
Sources of the elements in the sandstone-type uranium deposits of the Colorado Plateau
Eugene M. Shoemaker, W.L. Newman, A.T. Miesch
1956, Trace Elements Investigations 629
Sandstone-type uranium deposits of the Colorado Plateau are epigenetic. Certain elements have been added locally to the sandstone host to form the deposits; the added fraction of each element in the deposits is call extrinsic to distinguish it from the part present in the original unmineralized host. The principal extrinsic...
The absorption spectra of the complexes of uranium (VI) with some β-diketones
H.I. Feinstein
1956, Trace Elements Investigations 631
The absorption spectra of the complexes of uranium (VI) with four β-dike tones were determined under various conditions of pH, concentration of uranium, and alcohol concentration. Under optimum conditions, the maximum molar absorptivity (31,200) is obtained using 2-furoyltrifluoroacetone. This compares with about 4,000 and 19,000 for the thiocyanate and dibenzoylmethane...
Semiquantitative spectrographic analysis and rank correlation in geochemistry
Francis J. Flanagan
1956, Trace Elements Investigations 628
The rank correlation coefficient, rs, which involves less computation than the product moment correlation coefficient, r, can be used to indicate the degree of relationship between two elements. The methods is applicable in situations where the assumptions underlying distribution correlation theory may not be satisfied. Semiquantitative spectrographic analyses can be...