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George Van Trump

Publications and source records attributed to George Van Trump.

12 recordsLinked to original sources
USGS1978

RFM (relative fraction magnitude): program explanation and computer program listing

The RFM (relative fraction magnitude) program is proposed as an aid in the estimation of depth to ore-mineral concentration. This estimate is based on the determination of the relative position of the sampled surface plane within the zonational framework of a hydrothermal sulfide mineralization. The program requires analytical data on two sample fractions collected at the same localities. The first of these must selectively concentrate iron and manganese oxides (exclusive of magnetite) and, the other, the sulfides and their oxidized zone derivatives.

Open-File Report↗
USGS1978

Least-squares refinement of powder diffraction data for unit cell parameters: Program listing for DEC 10 computer

This FORTRAN computer program is a time-sharing version of the classic program of Appleman and Evans (1973) and Evans, Appleman, and Handwerker (1963), which indexes powder patterns and refines unit-cell dimensions. The program, originally written to be processed in batch mode for an IBM computer, was modified to run in time-sharing mode on the DEC 10 computer. This version does not depart philosophically from the original program; however, the input and output formats have been adapted to the time-sharing terminal. These modifications and the actual running of the program are not discussed in detail here, as this report is intended only to make the program itself available. Examples of the input and output formats are shown on pages 3-8. Input can be entered through the terminal by two methods. An input file may either be independently created and then entered into the program later, or created directly through the interactive mode of the program. With the latter method a file of the input information may also be saved for later use. Both methods allow for the data to be edited after each refinement run. The output format has been changed to an 80-column width, common to many terminals. Only the last refinement cycle is printed and some of the statistical computations have been surpressed. Using the "Unit Cell" program from the terminal in a "real time" situation emphasizes the versatility of the program. This ability to interact directly with the computer gives the user a better appreciation of the program, its options, the data, and the problem being solved.

Open-File Report↗
USGS1978

Radiometric results and areal distribution for granitic samples from the Granite Mountains, Wyoming

Analyses of surface samples from the Granite Mountains, Wyoming, generally agree with the findings from drilling at two different localities. The dominant Precambrian granitic rock type is the biotitic phase of the granite of Lankin Dome. This rock type is characterized by high potassium and anomalously high thorium concentrations, and is the most favorable granitic source for the uranium deposits in the surrounding area. Areal distribution patterns for radioelement concentrations show that the most favorable source regions are located closest to known uranium deposits. Most of the granitic rocks in the Granite Mountains region are characterized by high thorium-uranium ratios. These high ratios are interpreted to be the result of uranium loss. Non-gaussian distribution of radioelement contents and poor correlation between radioelement pairs are interpreted to be the result of some redistribution of radioelements during the last phase of granite crystallization and to recent uranium loss. A good correlation between thorium and iron is attributed to the mobilization of thorium into microcrystalline iron oxides during a late portion of the magmatic history. A comparison of sulfur data for surface and shallow drill-hole samples suggests that sulfur has been removed from the granite to at least a depth of 20 m. The loss of uranium and sulfur from these samples suggests that other trace elements found in association with uranium deposits might have been removed from the granite.

Wyoming↗