Field Notebook: SD, CO, WY 1967
Page 109
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Transcription
to very large flat avoide. Shell goes from pzyom at base to fizhy, lighter, chunkier at top (1) 6.0+ Shell somewhat bretonite? Shell worthy to checked outcrop some though tissile underlit. Zone large is sept cones in upper foot?, locally, plenty type, much assoc. gypsum. 8