Figure F67. Altered glass fragment rimmed by two generations of smectite in Sample 192-1184A-42R-1, 147-150 cm. The outer rim of smectite mimics the outline of the glass clast and formed by replacement of the outer margin. The inner rim displays fibro-radial habit and formed later as the glass continued to be altered inward (field of view = 1.4 mm; photomicrograph ID#s 1184A_087 and 1184A_086). A. Plane-polarized light. B. Crossed polars; outer smectite rim has orange-brown polarization colors.

Figure F67. Altered glass fragment rimmed by two generations of smectite in Sample 192-1184A-42R-1, 147-150 cm. The outer rim of smectite mimics the outline of the glass clast and formed by replacement of the outer margin. The inner rim displays fibro-radial habit and formed later as the glass continued to be altered inward (field of view = 1.4 mm; photomicrograph ID#s 1184A_087 and 1184A_086). A. Plane-polarized light. B. Crossed polars; outer smectite rim has orange-brown polarization colors.