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NARROW
GeoRef Subject
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all geography including DSDP/ODP Sites and Legs
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Australasia
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Australia
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Otway Basin (1)
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New Zealand (1)
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Black Hills (2)
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Canada
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Clark Fork (1)
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Williston Basin (2)
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Sierra Nevada (1)
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United States
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Colorado
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Idaho
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Montana
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Big Snowy Mountains (1)
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Carbon County Montana (9)
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Park County Montana (2)
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New England (1)
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Powder River basin (2)
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South Dakota (2)
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U. S. Rocky Mountains
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Absaroka Range
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Beartooth Mountains (54)
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Bighorn Mountains (5)
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Laramie Mountains (1)
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Owl Creek Mountains (1)
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Uinta Mountains (2)
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Wet Mountains (1)
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Uinta Basin (1)
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Washington (1)
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Carbon County Wyoming (1)
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Heart Mountain Fault (2)
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Owl Creek Mountains (1)
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Park County Wyoming (13)
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Sublette County Wyoming (1)
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Wyoming Province (4)
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commodities
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elements, isotopes
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Pb-207/Pb-204 (1)
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Pb-208/Pb-204 (1)
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stable isotopes
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Nd-144/Nd-143 (5)
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Pb-206/Pb-204 (2)
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Lu/Hf (1)
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metals
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potassium (3)
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gold (1)
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lead
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platinum group
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rare earths
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cerium (1)
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lanthanum (1)
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neodymium
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Nd-144/Nd-143 (5)
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fossils
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Chordata
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Vertebrata
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Tetrapoda
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Mammalia (1)
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Invertebrata
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Cnidaria
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Anthozoa
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Tabulata (1)
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Cenozoic
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Tertiary
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Paleogene
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Absaroka Supergroup (5)
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lower Eocene
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Willwood Formation (3)
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Wind River Formation (1)
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middle Eocene
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Aycross Formation (2)
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Paleocene
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lower Paleocene (1)
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Paleocene-Eocene Thermal Maximum (1)
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upper Cenozoic (1)
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Mesozoic
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Cretaceous
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Cloverly Formation (1)
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Mowry Shale (1)
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Cody Shale (1)
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Jurassic
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Morrison Formation (1)
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Nugget Sandstone (1)
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Triassic
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Lower Triassic
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Thaynes Formation (1)
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Paleozoic
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Cambrian
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Middle Cambrian
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Flathead Sandstone (1)
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Carboniferous
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Mississippian
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Lower Mississippian
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Lodgepole Formation (1)
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Pennsylvanian (1)
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Devonian (3)
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Ordovician
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Upper Ordovician
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Bighorn Dolomite (1)
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Tensleep Sandstone (1)
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upper Paleozoic
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Bakken Formation (1)
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Precambrian
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Archean
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J-M Reef (1)
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Mesoarchean (1)
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Hadean (1)
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Stillwater Complex (8)
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upper Precambrian
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Proterozoic
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Tonian (1)
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igneous rocks
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silicates
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pyroxene group
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framework silicates
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silica minerals
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orthosilicates
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zircon group
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zircon (11)
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sorosilicates
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epidote group
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allanite (1)
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ring silicates
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cordierite (1)
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sheet silicates
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biotite (4)
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-
-
Primary terms
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absolute age (21)
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associations (3)
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Australasia
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Australia
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Otway Basin (1)
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New Zealand (1)
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bibliography (2)
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Canada
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Western Canada
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carbon
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C-14 (1)
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Cenozoic
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Quaternary
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Holocene (1)
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Pleistocene (1)
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Tertiary
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Neogene
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Miocene (1)
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Pliocene (2)
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Paleogene
-
Eocene
-
Absaroka Supergroup (5)
-
Green River Formation (1)
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lower Eocene
-
Willwood Formation (3)
-
Wind River Formation (1)
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Ypresian (1)
-
-
middle Eocene
-
Aycross Formation (2)
-
-
-
Paleocene
-
lower Paleocene (1)
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upper Paleocene
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Tiffanian (1)
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-
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Paleocene-Eocene Thermal Maximum (1)
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upper Cenozoic (1)
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chemical analysis (1)
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Chordata
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Vertebrata
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Mammalia (1)
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crust (3)
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crystal growth (3)
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hydrogeology (1)
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hydrology (1)
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igneous rocks
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plutonic rocks
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diabase
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quartz diabase (1)
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diorites (1)
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gabbros (2)
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granites (2)
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quartz monzonite (1)
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ultramafics
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chromitite (1)
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-
-
volcanic rocks
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adakites (1)
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andesites (2)
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basalts
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shoshonite (4)
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dacites (1)
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pyroclastics
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tuff (2)
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rhyolites (1)
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trachyandesites
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absarokite (2)
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inclusions
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fluid inclusions (1)
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intrusions (14)
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Invertebrata
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Anthozoa
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Zoantharia
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Tabulata (1)
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isostasy (1)
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isotopes
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radioactive isotopes
-
C-14 (1)
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Pb-206/Pb-204 (2)
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Pb-207/Pb-204 (1)
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Pb-208/Pb-204 (1)
-
-
stable isotopes
-
Nd-144/Nd-143 (5)
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Pb-206/Pb-204 (2)
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Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
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Sr-87/Sr-86 (3)
-
-
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lava (2)
-
magmas (12)
-
mantle (5)
-
maps (13)
-
Mesozoic
-
Cretaceous
-
Lower Cretaceous
-
Cloverly Formation (1)
-
Mowry Shale (1)
-
-
Upper Cretaceous
-
Cody Shale (1)
-
Frontier Formation (1)
-
Lance Formation (1)
-
Mesaverde Group (1)
-
-
-
Jurassic
-
Lower Jurassic (1)
-
Middle Jurassic (1)
-
Twin Creek Limestone (1)
-
Upper Jurassic
-
Morrison Formation (1)
-
Sundance Formation (1)
-
-
-
Nugget Sandstone (1)
-
Triassic
-
Lower Triassic
-
Thaynes Formation (1)
-
-
-
-
metal ores
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chromite ores (1)
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copper ores (1)
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iron ores (1)
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uranium ores (1)
-
-
metals
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alkali metals
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potassium (3)
-
rubidium (1)
-
-
alkaline earth metals
-
barium (1)
-
magnesium (1)
-
strontium
-
Sr-87/Sr-86 (3)
-
-
-
gold (1)
-
iron
-
ferrous iron (1)
-
-
lead
-
Pb-206/Pb-204 (2)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
platinum group
-
platinum (1)
-
rhodium (1)
-
-
rare earths
-
cerium (1)
-
lanthanum (1)
-
neodymium
-
Nd-144/Nd-143 (5)
-
-
-
-
metamorphic rocks
-
amphibolites
-
orthoamphibolite (1)
-
-
gneisses
-
granite gneiss (1)
-
-
hornfels (1)
-
metaigneous rocks (2)
-
metasedimentary rocks (3)
-
metavolcanic rocks (1)
-
mylonites (1)
-
quartzites (1)
-
schists
-
biotite schist (1)
-
-
-
metamorphism (7)
-
metasomatism (4)
-
mineral exploration (1)
-
mineralogy (5)
-
minerals (3)
-
North America
-
Purcell Mountains (1)
-
Rio Grande Rift (1)
-
Rocky Mountains
-
Northern Rocky Mountains (1)
-
U. S. Rocky Mountains
-
Absaroka Range
-
Beartooth Mountains (54)
-
-
Bighorn Mountains (5)
-
Laramie Mountains (1)
-
Owl Creek Mountains (1)
-
San Juan Mountains (1)
-
Sangre de Cristo Mountains (1)
-
Tobacco Root Mountains (1)
-
Uinta Mountains (2)
-
Wet Mountains (1)
-
Wind River Range (5)
-
-
-
Williston Basin (2)
-
-
oil and gas fields (2)
-
orogeny (4)
-
paleoclimatology (2)
-
paleogeography (3)
-
paleomagnetism (2)
-
Paleozoic
-
Cambrian
-
Middle Cambrian
-
Flathead Sandstone (1)
-
-
-
Carboniferous
-
Mississippian
-
Lower Mississippian
-
Lodgepole Formation (1)
-
-
-
Pennsylvanian (1)
-
-
Devonian (3)
-
Ordovician
-
Upper Ordovician
-
Bighorn Dolomite (1)
-
-
-
Tensleep Sandstone (1)
-
upper Paleozoic
-
Bakken Formation (1)
-
-
-
paragenesis (2)
-
petroleum
-
natural gas
-
shale gas (1)
-
-
shale oil (1)
-
-
petrology (17)
-
phase equilibria (3)
-
pollution (1)
-
Precambrian
-
Archean
-
J-M Reef (1)
-
Mesoarchean (1)
-
Neoarchean (1)
-
-
Hadean (1)
-
Stillwater Complex (8)
-
upper Precambrian
-
Proterozoic
-
Neoproterozoic
-
Tonian (1)
-
-
-
-
-
remote sensing (1)
-
rock mechanics (1)
-
sedimentary petrology (1)
-
sedimentary rocks
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carbonate rocks
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limestone (2)
-
-
chemically precipitated rocks
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iron formations
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banded iron formations (1)
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-
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clastic rocks
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conglomerate (3)
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marl (1)
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mudstone (1)
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sandstone (2)
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shale (1)
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siltstone (1)
-
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coal
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bituminous coal (1)
-
lignite (1)
-
-
-
sedimentary structures
-
planar bedding structures
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cross-stratification (1)
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imbrication (1)
-
-
-
sedimentation (2)
-
spectroscopy (1)
-
stratigraphy (4)
-
structural analysis (2)
-
structural geology (14)
-
tectonics (14)
-
United States
-
Bighorn Basin (5)
-
Clark's Fork Basin (1)
-
Colorado
-
Douglas County Colorado (1)
-
Elbert County Colorado (1)
-
Garfield County Colorado (1)
-
Piceance Basin (1)
-
Wet Mountains (1)
-
-
Denver Basin (1)
-
Idaho
-
Elmore County Idaho (1)
-
Idaho National Laboratory (1)
-
Snake River plain (1)
-
-
Montana
-
Big Snowy Mountains (1)
-
Carbon County Montana (9)
-
Madison County Montana
-
Tobacco Root Mountains (1)
-
-
Park County Montana (2)
-
Stillwater County Montana (3)
-
Sweet Grass County Montana (4)
-
-
New England (1)
-
New Mexico
-
Rio Arriba County New Mexico
-
Nacimiento Mountains (1)
-
-
-
Powder River basin (2)
-
Sevier orogenic belt (1)
-
South Dakota (2)
-
U. S. Rocky Mountains
-
Absaroka Range
-
Beartooth Mountains (54)
-
-
Bighorn Mountains (5)
-
Laramie Mountains (1)
-
Owl Creek Mountains (1)
-
San Juan Mountains (1)
-
Sangre de Cristo Mountains (1)
-
Tobacco Root Mountains (1)
-
Uinta Mountains (2)
-
Wet Mountains (1)
-
Wind River Range (5)
-
-
Uinta Basin (1)
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Utah
-
Daggett County Utah (1)
-
-
Washington (1)
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Western U.S. (3)
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Wisconsin (1)
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Wyoming
-
Carbon County Wyoming (1)
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Fremont County Wyoming (1)
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Heart Mountain Fault (2)
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Lincoln County Wyoming (1)
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Natrona County Wyoming (1)
-
Owl Creek Mountains (1)
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Park County Wyoming (13)
-
Sublette County Wyoming (1)
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Uinta County Wyoming (2)
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Wind River Range (5)
-
-
Wyoming Province (4)
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Yellowstone National Park (1)
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Yellowstone River (1)
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volcanology (1)
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weathering (1)
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rock formations
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Fort Union Formation (4)
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Wapiti Formation (2)
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sedimentary rocks
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sedimentary rocks
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carbonate rocks
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limestone (2)
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chemically precipitated rocks
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iron formations
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banded iron formations (1)
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clastic rocks
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conglomerate (3)
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coal
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bituminous coal (1)
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volcaniclastics (2)
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sedimentary structures
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sedimentary structures
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planar bedding structures
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cross-stratification (1)
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imbrication (1)
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sediments
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volcaniclastics (2)
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Absaroka Range
Analysis of the fluvial stratigraphic response to the Paleocene–Eocene Thermal Maximum in the Bighorn Basin, U.S.A.
Eocene Andesitic Adakite from Lone Mountain, Southwestern Montana
ABSTRACT We report the results of 167 calcite twinning strain analyses (131 limestones and 36 calcite veins, n = 7368 twin measurements) from the Teton–Gros Ventre (west; n = 21), Wind River ( n = 43), Beartooth ( n = 32), Bighorn ( n = 32), and Black Hills (east; n = 11) Laramide uplifts. Country rock limestones record only a layer-parallel shortening (LPS) strain fabric in many orientations across the region. Synorogenic veins record both vein-parallel shortening (VPS) and vein-normal shortening (VNS) fabrics in many orientations. Twinning strain overprints were not observed in the limestone or vein samples in the supracrustal sedimentary veneer (i.e., drape folds), thereby suggesting that the deformation and uplift of Archean crystalline rocks that form Laramide structures were dominated by offset on faults in the Archean crystalline basement and associated shortening in the midcrust. The twinning strains in the pre-Sevier Jurassic Sundance Formation, in the frontal Prospect thrust of the Sevier belt, and in the distal (eastern) foreland preserve an LPS oriented approximately E-W. This LPS fabric is rotated in unique orientations in Laramide uplifts, suggesting that all but the Bighorn Mountains were uplifted by oblique-slip faults. Detailed field and twinning strain studies of drape folds identified second-order complexities, including: layer-parallel slip through the fold axis (Clarks Fork anticline), attenuation of the sedimentary section and fold axis rotation (Rattlesnake Mountain), rotation of the fold axis and LPS fabric (Derby Dome), and vertical rotations of the LPS fabric about a horizontal axis with 35% attenuation of the sedimentary section (eastern Bighorns). Regional cross sections (E-W) across the Laramide province have an excess of sedimentary veneer rocks that balance with displacement on a detachment at 30 km depth and perhaps along the Moho discontinuity at 40 km depth. Crustal volumes in the Wyoming Province balance when deformation in the western hinterland is included.
Stratigraphic relationships along the monoclinal eastern base of Bald Ridge and northwestern edge of Wyoming’s Bighorn Basin, U.S.A.
Geochemical, isotopic, and U–Pb zircon study of the central and southern portions of the 780 Ma Gunbarrel Large Igneous Province in western Laurentia
Chlorine incorporation into amphibole and biotite in high-grade iron-formations: Interplay between crystallography and metamorphic fluids
Subsurface structural and mineralogical characterization of the Laramide South Prairie fault in the Stillwater Complex, Beartooth Mountains, Montana
Ba-RICH K-FELDSPAR FROM MAFIC XENOLITHS WITHIN MESOARCHEAN GRANITIC ROCKS, BEARTOOTH MOUNTAINS, MONTANA, USA: INDICATORS FOR BARIUM METASOMATISM
Abstract A synthesis of low-temperature thermochronologic results throughout the Laramide foreland illustrates that samples from wellbores in Laramide basins record either (1) detrital Laramide or older cooling ages in the upper ~1 km (0.62 mi) of the wellbore, with younger ages at greater depths as temperatures increase; or (2) Neogene cooling ages. Surface samples from Laramide ranges typically record either Laramide or older cooling ages. It is apparent that for any particular area the complexity of the cooling history, and hence the tectonic history interpreted from the cooling history, increases as the number of studies or the area covered by a study increases. Most Laramide ranges probably experienced a complex tectono-thermal evolution. Deriving a regional timing sequence for the evolution of the Laramide basins and ranges is still elusive, although a compilation of low-temperature thermochronology data from ranges in the Laramide foreland suggests a younging of the ranges to the south and southwest. Studies of subsurface samples from Laramide basins have, in some cases, been integrated with and used to constrain results from basin burial-history modeling. Current exploration for unconventional shale-oil or shale-gas plays in the Rocky Mountains has renewed interest in thermal and burial history modeling as an aid in evaluating thermal maturity and understanding petroleum systems.This paper suggests that low-temperature thermochronometers are underutilized tools that can provide additional constraints to burial-history modeling and source rock evaluation in the Rocky Mountain region.
Abstract The consistent low porosity and permeability of reservoirs in the Bakken petroleum system, in the Williston Basin, have increased the need for fracture studies. Although situated in an intracratonic setting, the Williston Basin displays evidence of deformation enabling the presence of regional and local fracturing. In this study, applicable fracture models are utilized to delineate regional and local fracture orientations within the Williston Region. Northwest and northeast regional fracture trends have been determined by integrating results from previous fracture studies, collecting field data at outcrop locations in the Williston Basin Region, and from subsurface three-dimensional (3-D) seismic data in the Williston Basin. A right-lateral wrench fault strain ellipse model is offered to explain these regional trends. Fracture orientations acquired from outcrop sites (Little Rocky Mountains, Big Snowy Mountains, and Beartooth Mountains) also reveal local, structurally controlled, conjugate fracture trends that are parallel or perpendicular to the structural axis. Using curvature analysis on the interpreted 3-D seismic data, local fracture patterns are also observed within the Williston Basin. When regional and local trends are compared, overlap occurs in fracture orientation showing preference to fractures produced from local structures. Regional and local trends are also incorporated into a mechanical stratigraphy study using field observations of outcropping Bakken age equivalent and lithologically similar strata from the Bighorn Basin. Dense fracturing occurs within the middle Bakken equivalent member of the Cottonwood Canyon Formation. Extensive fractures that are perpendicular to bedding are also observed and cut through the lower bounding Three Forks Formation, Cottonwood Canyon Formation, and overlying Lodgepole Formation.
Trace Element and Lu-Hf Systematics in Hadean-Archean Detrital Zircons: Implications for Crustal Evolution
The Yellowstone-Bighorn Research Association (YBRA) is a nonprofit research and teaching organization chartered in the state of Montana in 1936. YBRA maintains a field station south of Red Lodge, Montana, at the foot of the Beartooth Mountains at the NW corner of the Bighorn Basin. The YBRA Field Station has been host to a wide variety of primarily geological field courses and research exercises, including a YBRA-sponsored Summer Course in Geologic Field Methods , offered initially by Princeton University and subsequently by the University of Pennsylvania and the University of Houston. Enrollments in that course vary from year to year, an experience shared by other field-course programs. The YBRA field station does not depend exclusively on field-course enrollment; by diversifying its client base, YBRA has been able to operate effectively through high-amplitude variations in enrollment in traditional courses in field geology.