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Transcription
SECTION 8210
Section runs from base of Mantua lentil through lignitic base of Fort Union
Formation and uppermost Lance Formation.
Polecat Bench N. Side 180 m NW of Mantua Quarry, center e. line, NW, NE, SW ¼
sec 31, T7N, R98W, Park County, Wyoming. Old locality 7839. Garland 7½' Quad.
Pollen and Iridium sampling at even 10 cm intervals. Sampling with steel tools.
Dug 2 trenches about 1 foot apart through weathered zone. No wedding rings.
Final digging done with a ceramic spatula.
Section starts about 1.8 m below the base of a lignite marking the bottom of
the Fort Union Formation and ends in a sandstone bed of the Mantua lentil of
the Fort Union Formation.
UNIT
Elevation at Base
Fort Union Formation:
2.6 Top of section as measured in Mantua lentil.
Mantua Lentil: sandstone: very fine grained,
subangular, dirty, cross-bedded, ledge-forming,
color 5Y 7/2, lower contact irregular. Base
of Mantua lentil.
2.52 .08
2.5 Shale: thin, lignitic just below contact
Mudstone: Parallel bedded, 5Y 6/1, with stringers
of lignite. Interbedded segment of thin wavy
lignite stringers and 1 to 4 cm beds of mudstone.
2.01 .49
1.92 Lignite .09
1.86 Clay interbed 5Y 6/1 .06
1.79 Lignite: Marks base of Fort Union Formation .07
Lance Formation:
Underclay, 5Y 6/1, with roots, comminuted plant
matter and contorted carbonaceous laminae.
1.7 - 1.79 above base. Underclay 5Y 6/1, with
limonite stains on joints, and root impressions.
1.62 .17
Mudstone: with gypsum on joints. Stringers of
coal 1-2 mm thick above 1.56.
1.42 .2