MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.
-
Upload
rosaline-west -
Category
Documents
-
view
213 -
download
1
Transcript of MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.
![Page 1: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/1.jpg)
MESOZOIC STRATIGRAPHY
BIG HORN AND POWER RIVER BASINS
![Page 2: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/2.jpg)
Early
Permian
![Page 3: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/3.jpg)
![Page 4: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/4.jpg)
Late Triassic
![Page 5: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/5.jpg)
![Page 6: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/6.jpg)
Triassic System
Thick succession of red beds. Variable amounts of soft sandstone and mudstone.
Chugwater Formation here, Spearfish in the Black Hills. Dinwoody Formation is included in the Absarokas.
Dense, thin, laminated, light-colored limestones (Alcova and Popo Agie) occur near the top.
Thick gypsum at top to the west (in part Early Jurassic).
Arid coastal plane.
![Page 7: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/7.jpg)
Chugwater Formation
![Page 8: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/8.jpg)
![Page 9: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/9.jpg)
Middle Jurassic (160 Ma). Major arc magmatism Initial
collision between southern Wrangellia and Cordilleran margin at approximately the latitude of Klamaths and Sierras
Fringing arcs south of collision zone Ophiolites obducted in collision zone and in inter arc region between Cordilleran arc and fringing arcs
Foreland basin in Utah and thrusting in Nevada
Rift basin in southwestern North America related to opening Gulf of Mexico
![Page 10: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/10.jpg)
Middle Jurassic
![Page 11: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/11.jpg)
Late Jurassic
![Page 12: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/12.jpg)
Jurassic System Disconformably overlies the Triassic. Only
Upper Jurassic rocks are present here. Sundance Formation - Here it is largely marine,
and consists of green shale with some thin limestone and sandstone. Shale has belemnite fossils. “Oyster Bed” is present near the top. Yellow rippled sandstone near the top. Ripples are symmetric.
Morrison – Generally poorly exposed here. Consists of interbedded red, yellow, and purple mudstone, sandstone and conglomerate. Humid coastal plane? Dinosaur bones.
![Page 13: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/13.jpg)
Sundance Formation Largely marine, Lower green shale with some thin limestone and sandstone. Shale has belemnite fossils. “Oyster Bed” is present near the top. Yellow rippled sandstone near the top. Ripples are both asymmetric &symmetric.
![Page 14: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/14.jpg)
![Page 15: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/15.jpg)
Morrison Fm.
Morrison – Generally poorly exposed here. Consists of interbedded red, yellow, and purple mudstone, sandstone and conglomerate.
Humid coastal plane? Dinosaur bones.
![Page 16: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/16.jpg)
![Page 17: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/17.jpg)
Early Cretaceous
![Page 18: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/18.jpg)
Major magmatic activity in two belts (110-85 Ma) followed by strong decline and null in magmatic activity (80-40 Ma) Andean-style segmentation of Farallon arc from Central America to Southern California Sevier thrusting continued and foreland basin shifted locus of subsidence southward in response to shallow Laramide subduction (shallow angle)
Late Cretaceous (85 Ma)
![Page 19: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/19.jpg)
Late Cretaceous
![Page 20: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/20.jpg)
Lower Cretaceous System
Disconformably overlies the Jurassic System. Cloverly Formation. Interbedded sandstone
and shale. “Rusty Beds” locally form hogbacks. Deltaic system with channels, delta bay, and pro-delta facies.
Thermopolis Formation – Black marine shale similar to the Pierre.
Mowry Formation – Resistant silicified mudstone. Distinct silver-grey, rarely fully vegetated. Environment uncertain. Some bentonite beds in the Bighorn Basin are mined.
![Page 21: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/21.jpg)
Cloverly Formation. Interbedded sandstone and shale. “Rusty Beds” locally form hogbacks. Deltaic system with channels, delta bay, and pro-delta facies.
![Page 22: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/22.jpg)
Thermopolis Shale
![Page 23: MESOZOIC STRATIGRAPHY BIG HORN AND POWER RIVER BASINS.](https://reader036.fdocuments.in/reader036/viewer/2022081603/56649f155503460f94c2acd8/html5/thumbnails/23.jpg)