Proton Microprobe Analysis of Trace-Element Variations in Vitrinites in the Same and Different Coal Beds

Authors

J. A. Minkin, U.S. Geological Survey
E. C. T. Chao, U.S. Geological Survey
Herma Blank, Max-Planck-Institut f. Kernphysik
F. T. Dulong, U.S. Geological Survey

Abstract

The PIXE (proton-induced X-ray emission) microprobe can be used for nondestructive, in-situ analyses of areas as small as those analyzed by the electron microprobe, and has a sensitivity of detection as much as two orders of magnitude better than the electron microprobe. Preliminary studies demonstrated that PIXE provides a capability for quantitative determination of elemental concentrations in individual coal maceral grains with a detection limit of 1-10 ppm for most elements analyzed. Encouraged by the earlier results, we carried out the analyses reported below to examine trace element variations laterally (over a km range) as well as vertically (cm to m) in the I and J coal beds in the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in central Utah, and to compare the data with the data from two samples of eastern coals of Pennsylvanian age. The data obtained illustrate the sensitivity of detection obtainable with the PIXE microprobe in analysis of coal macerals. Such data are of value in tracing the geochemical conditions during deposition and diagenesis of a coal bed, and in assessing potential applications and problems of combustion, gasification, or liquefaction of particular coals.

Recommended Citation

Minkin, J. A.; Chao, E. C. T.; Blank, Herma; and Dulong, F. T. (1987) "Proton Microprobe Analysis of Trace-Element Variations in Vitrinites in the Same and Different Coal Beds," Scanning Microscopy: Vol. 1: No. 2, Article 9.
Available at: https://digitalcommons.usu.edu/microscopy/vol1/iss2/9