Cross section showing depositional environments and lithologies of some Upper Cretaceous and Tertiary rocks from Debeque to the north-central Piceance Creek basin, Colorado

1978 ◽  
Author(s):  
Ronald C. Johnson
1985 ◽  
Vol 22 (9) ◽  
pp. 1274-1285 ◽  
Author(s):  
James H. Trexler Jr.

The Cretaceous Methow Basin of north-central Washington is the southernmost of a series of Mesozoic successor basins in the Cordillera of western North America. The Albian–Campanian(?) Virginian Ridge Formation comprises three members, newly defined here, that gradationally interfinger with each other and grade laterally and upward into overlying strata. Detailed stratigraphic analysts of the Virginian Ridge Formation and of the intimately related parts of the Winthrop and Midnight Peak formations indicates that these units represent complexly interfingering facies derived from a variety of sources, both to the west and to the east of the basin and locally within the system. This study suggests a detailed model for the history of the Upper Cretaceous Methow Basin: generation of a restricted basin with a stable, roughly north–south-trending axis, filled by a stable, east-derived fluvial and deltaic system (Winthrop Formation) interfingering with a laterally amalgamated, west-derived northward and eastward transgressive fan-delta system (Virginian Ridge Formation). The sequence grades upward into, and finally is overwhelmed by, locally derived volcanics of the Midnight Peak Formation. Similar, and in part coeval, successor basin sequences throughout the North American Cordillera may have been generated in response to similar tectonic settings.


2021 ◽  
Vol 240 ◽  
pp. 04001
Author(s):  
Abdelouhed Farah ◽  
Ahmed Algouti ◽  
Abdellah Algouti ◽  
Fatiha Hadach ◽  
zahra Mourabit

The study area belongs to the southern edge of the central High Atlas. It is limited to the North by the Sub-atlasic accident and to the South by the extension of the Eastern Anti Atlas formations. To determine the depositional environments of the Senonian series, a sedimentological analysis of the facies was carried out based on field observations by the recognition of sedimentary structures and textures. An exoscopic analysis of the quartz grains was also carried out by a systematic prospecting of the grain relief and of all the characters that will appear on the surface of the grain after the formation of the mother rock at the origin place, during transport, immobilization phases and deposition. It seems very interesting to prospect for the clayey side in these Upper Cretaceous reddish formations because the evolution of the clayey and non-clayey assemblages in this central basin of the High Atlas will depend mainly on the combination of tectonic, eustatic, climatic and other influences. The Senonian of Foum El Kous which has a less important thickness corresponds to continental deposits that act the role of a natural barrier that separates on both sides the two sub-basins: Sidi Ali Oubork in the East and Ait youl in the West.


2020 ◽  
Author(s):  
David C. Greene

Geosphere, February 2014, v. 10, p. 148-169, doi:10.1130/GES00972.1, Plate 3 - Cross section of the north central Confusion Range, B–B′.


1972 ◽  
Vol 9 (7) ◽  
pp. 903-913 ◽  
Author(s):  
G. H. Eisbacher

Mapping in the core of the north–central Cordillera of British Columbia has revealed a system of relatively closely spaced steeply dipping faults cutting across an earlier penetrative fabric consisting of recumbent folds and intensely cleaved sedimentary rocks. The earlier (Mid – Late Jurassic) penetrative deformation was separated from the later (Late Cretaceous – Tertiary) deformation by regional uplift, normal faulting, and initiation of intermontane deposition. The Upper Cretaceous – Lower Tertiary Sifton Formation was involved only in the later deformational pulse. Kink folding and oblique faulting are the principal mechanisms of the later pulse. The orientation of principal regional contraction changed from an early WSW–ENE direction to a late SSW–NNE direction. From this it is inferred that some of the young lineaments along and near the Rocky Mountain Trench are probably oblique–slip faults with unknown, but probably small right–lateral slip components.


2019 ◽  
Vol 55 (1) ◽  
pp. 241
Author(s):  
Nikolaos Dimopoulos ◽  
Eleftherios Georgoulas ◽  
Savvas Peridis ◽  
George Iliopoulos ◽  
Nikolina Bourli ◽  
...  

Sedimentological studies of the Cretaceous limestones in the central Ionian basin (Amfilochia, Arta as well as Kerasonas areas) indicate that these deposits are composed of calciturbidites interbedded with breccia-microbreccia deposits. In the Amfilochia new cross-section, with a NNW-SSE direction, the lower Cretaceous Vigla limestones and Vigla shales were outcropped for the first time. This section is directed parallel to the paleo Ionian basin axis and the fact of the lateral discontinuity of Vigla limestones and Vigla shales indicate that during the sedimentation of these two Formations there was a restriction along the paleo basin axis, probably due to synsedimentary transfer fault activity. Forty-two (42) samples from Vigla shales were analyzed for their content in CaCO3 and TOC, showed that these sediments present poor to fair hydrocarbon potential. In the Arta new cross-section, with a NE-SW direction, the Upper Cretaceous Senonian deposits showed strong deformation that took place during the compressional regime that affected the Ionian basin after sedimentation. This deformation appears stronger in the western part being close to a major thrust, and thus it is possible that this deformation could be responsible for the high secondary porosity of Upper Cretaceous deposits. Microfacies analysis of these deposits showed in general that deep-sea depositional environments prevailed, nevertheless in a few cases indications for the presence of environments with a shallow character imply the existence of isolated carbonate platforms close to the studied sections. In the studied sections with an E-W direction, no lateral changes were observed in the depositional conditions within the same Formation introducing standard depositional conditions across the paleo basin.


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