pubs.usgs.govCOAL BED SYMBOL AND NAME RS-7 TRACE COAL BED OUTCROP - Showing symbol of name of coal...
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pubs.usgs.govCOAL BED SYMBOL AND NAME RS-7 TRACE COAL BED OUTCROP - Showing symbol of name of coal bed as 11 st ed above. Arrow points toward coal-bearing area. Dashed where inferred
