The abundance and distribution of antimony in red-beds of the Devonian Catskill Formation, eastern Pennsylvania, U.S.A.

Abstract

A total of 195 sandstones and shales from red-beds of the Catskill Formation have been analyzed for Sb by epithermal neutron activation and for major elements by plasma emission spectrometry. The mean Sb content is 1.5 ppm for shales and 0.7 ppm for sandstone, in good agreement with the relatively few previous determinations for sedimentary rocks. Sb correlates positively with components of the fine-grained fraction (mica, Fe-oxide, chlorite) and with chemical elements in this fraction (Fe, Al, Mg, K, etc.), and correlates inversely with quartz and SiO 2. Gray-green sandstones and shales average slightly less Sb than red sandstones and shales, probably because of diagenetic redistribution of Sb, which is concentrated along with Cu, Ag, As and U in red-bed Cu occurrences of the region. The strongest correlation is with Fe, suggesting that Fe-oxides may be a major host. Factor analysis also suggests an affinity with Ca and Na, indicating diagenetic changes or red-beds derived from differing source areas.