Facies analysis and sequence stratigraphic framework of upper Campanian strata (Neslen and Mount Garfield formations, Bluecastle Tongue of the Castlegate sandstone, and Mancos shale), Eastern Book cliffs, Colorado and Utah

Data Series ◽  
10.3133/ds69g ◽  
2004 ◽  
Author(s):  
Mark A. Kirschbaum ◽  
Robert D. Hettinger
Keyword(s):  
Facies Analysis ◽  
Sequence Stratigraphic ◽  
Book Cliffs ◽  
Mancos Shale ◽  
Stratigraphic Framework ◽  
Upper Campanian

Carbonate Cementation in a Sequence-Stratigraphic Framework: Upper Cretaceous Sandstones, Book Cliffs, Utah-Colorado

2000 ◽  
Vol 70 (2) ◽  
pp. 360-372 ◽  
Author(s):  
K. G. Taylor ◽  
R. L. Gawthorpe ◽  
C. D. Curtis ◽  
J. D. Marshall ◽  
D. N. Awwiller
Keyword(s):  
Upper Cretaceous ◽  
Sequence Stratigraphic ◽  
Book Cliffs ◽  
Stratigraphic Framework ◽  
Carbonate Cementation

Sequence stratigraphy and regional context of the Mancos-Niobrara in the northern San Juan Basin

2021 ◽  
Vol 58 (2) ◽  
pp. 105-157
Author(s):  
Walter W. Nelson ◽  
Stephen A. Sonnenberg
Keyword(s):  
San Juan ◽  
Front Range ◽  
Low Oxygen ◽  
Niobrara Formation ◽  
Reservoir Properties ◽  
San Juan Basin ◽  
Sequence Stratigraphic ◽  
Mancos Shale ◽  
Stratigraphic Framework ◽  
Oxygen Conditions

In the northern San Juan Basin, the Niobrara Formation is represented by the upper half of the Mancos Shale (the Smoky Hill Member and Cortez Member). This section is generally equivalent to the Niobrara Formation along the Colorado Front Range. Although the Fort Hays Limestone is absent west of Pagosa Springs, the C Chalk and B Chalk are well-expressed as two resistant bench-forming calcareous units in the northern San Juan Basin. These two calcareous units have also been established as prospective hydrocarbon targets by operators in the area. Calcareous facies equivalent to the A Chalk were not deposited in the northern San Juan Basin due to siliciclastic dilution during the regressive latter half of the Niobrara marine cycle. The overall third-order Niobrara marine cycle includes these members of the Mancos Shale: the Juana Lopez, Montezuma Valley, Smoky Hill, and Cortez members. The Smoky Hill Member sits just above the basal Niobrara unconformity in most of the study area, and the entire section also has greater thickness and siliciclastic content than its equivalent farther east along the Front Range. Several extensive outcrop locations (in and around Pagosa Springs, Piedra, and Durango, CO) along with three new cores along the CO-NM border form the foundation for sequence stratigraphic interpretation of the Niobrara marine cycle in this study. All these locations and cores were tied back to the Mancos reference section at Mesa Verde National Park established by Leckie et al. (1997) which provides detailed description and biostratigraphy for the entire Mancos Shale. Establishing and applying a sequence stratigraphic framework to any section creates consistent reference standards for communication, research, and further correlation. Comparisons of chemostratigraphic data from equivalent strata between the northern San Juan Basin and Denver-Julesburg (DJ) Basin reveal significant differences in the timing and style of source-rock deposition (and associated low-oxygen conditions). The sequence stratigraphic framework also emphasizes tremendous lateral facies changes in the basal Niobrara section (i.e., Fort Hays Limestone to Tocito Sandstone). Once refined and applied, this stratigraphic framework can be used for predicting the distribution of reservoir properties, in addition to enhancing understanding of the Niobrara marine cycle and the Western Interior Seaway.

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