Geology and petrology of Tertiary lignites adjacent to Beartooth Mountain Front, Montana-Wyoming

Conference · Thu Sep 01 04:00:00 EDT 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6562779

Markowski, A K; Dutcher, R R

Along the eastern margin of the Beartooth front a sequence of Laramide conglomerates, sandstones, siltstones, shales, and minor coals are exposed. These minor Paleocene-Eocene coals, ranging from lignite to subbituminous in rank, are the focus of this study. Four coal exposures were sampled along a north-south strip (17 mi, 27 km), proximal to the Beartooth front. These coals range in thickness from less than a 1-in. (2.5 cm) lens to about 10 ft (3 m) and contain partings of carbonaceous shale, shale, siltstone and sandstone. Two of the seams, designated as Meeteetse trail and Burgess Lignite occur in typical Fort Union sediments. The other, the Burgess Lignite locality, is composed of alternating papery fusinitic lignite, siltstones, thin lenses of channel sandstones, carbonaceous shales, and carbonaceous mudstones. The coals here are high in organic matter, fossil stems, leaves, megascopic resins, randomly oriented petrified tree stumps, and gypsiferous deposits. Two other localities, Gold Creed and Clarks Fork Canyon, are in Paleocene alluvial fan deposits. The Clarks Fork coals are found at the distal end of an alluvial fan system and dip rather gently basinward. The Gold Creek coals are found at the base of a fan interbedded with massive sandstones and conglomerates containing andesitic porphyry clasts up to 1.5 ft (0.4 m) in maximum dimension. The Fort Union Formation in this area includes lacustrine, paludal, fluvial, and conglomeratic members. Petrographic examination reveals well preserved cell structure, especially in the fusinoid macerals. Although the coals have undergone severe alteration and weathering, they still exhibit excellent fluorescence properties.

• Research Organization: Southern Illinois Univ., Carbondale
• OSTI ID: 6562779
• Report Number(s): CONF-8310301-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:9
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ALLUVIAL DEPOSITS
BROWN COAL
CARBONACEOUS MATERIALS
CENOZOIC ERA
COAL
COAL DEPOSITS
COAL RANK
COAL SEAMS
ENERGY SOURCES
FEDERAL REGION VIII
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
LIGNITE
MACERALS
MATERIALS
MINERAL RESOURCES
NORTH AMERICA
PETROGRAPHY
PETROLOGY
RESOURCES
TERTIARY PERIOD
USA