Economic Geology; January 2005; v. 100; no. 1;
p. 165-174; DOI: 10.2113/100.1.0165
© Society of Economic Geologists
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FIG. 5. A. Backscattered electron photomicrograph of laminated goethite.
Lamination is due to slight differences in chemical composition, such as
variable concentrations of alumina and manganese (sample M2-296). See text for
details. B. i. Reflected light photomicrograph of laminated hardbands of Ba-rich
cryptomelane and goethite (sample M2-296). ii, iii, and iv. Electron microprobe
mapping of the same area, showing the relative content of potassium, iron, and
manganese, respectively. Note that the cryptomelane is almost free of iron. C.
Reflected-light photomicrograph showing a quartzite breccia with angular clasts.
The veins are filled predominantly by goethite (sample M2-215).
Copyright © 2008 by Society of Economic Geologists
