Geology topics

B. Ingram

Publications and source records attributed to B. Ingram.

2 recordsLinked to original sources

USGS1963

Studies of fluid inclusions iii: Extraction and uantitative analysis of inclusions in the milligram range

A method has been developed for the extraction and chemical microanalysis of individual fluid inclusions , or groups of inclusions , in the milligram range . Usable quantitative analyses for Na, K, Ca, Mg, CI, B, and SO* have been obtained of mineral samples containing several milligrams of inclusion fluid , and with increased experimental errors, on fractional milligram samples. The steps involved are: 1) concentration of inclusions by sample selection and cutting; 2) electrolytic cleaning; 3) crushing in soft copper sample tube in vacuo; 4) conversion of emitted water to hydrogen and determination of its volume; 5) mass spectrometric determination of the D/H ratio if desired; 6) leaching of the crushed mineral to dissolve soluble salts remaining; 7) microanalysis of the filtrate by sensitive colorimetric and flame photometric methods. The method has been applied to determine the composition of fluid inclusions in mineral samples from several types of deposits, with special attention to a series of samples from Mississippi Valley-type ore deposits.

Economic Geology↗

USGS1955

Determination of small and large amounts of fluorine in rocks

Gelatinous silica and aluminum ions retard the distillation of fluorine in the Willard and Winter distillation method. A generally applicable, simple method for the determination of fluorine in rocks containing aluminum or silicon or both as major constituents was desired. In the procedure developed, the sample is fused with a mixture of sodium carbonate and zinc oxide, leached with water, and filtered. The residue is granular and retains nearly all of the silica. The fluorine in the filtrate is distilled directly from a perchloric acid-phosphoric acid mixture. Phosphoric acid permits the quantitative distillation of fluorine in the presence of much aluminum at the usual distillation temperature and without the collection of large volumes of distillate. The fluorine is determined either by microtitration with thorium nitrate or colorimetrically with thoron. The procedure is rapid and has yielded excellent results on silicate rocks and on samples from the aluminum phosphate (leached) zone of the Florida phosphate deposits.

Analytical Chemistry↗