Figure F4. Optical microscope view of thin section from surface hardground Core 194-1196B-1R. The lower part consists of a floatstone with abundant foraminifers and various macrofossils. Stromatolithic crust characterizes the upper part. Note abrupt color change to opaque black in upper right. Box shows area analyzed by electron microprobe (Fig. F11).

Figure F4. Optical microscope view of thin section from surface hardground Core 194-1196B-1R. The lower part consists of a floatstone with abundant foraminifers and various macrofossils. Stromatolithic crust characterizes the upper part. Note abrupt color change to opaque black in upper right. Box shows area analyzed by electron microprobe (Fig. F11).