Does the Owl Creek fault zone of north-central Wyoming extend to the Black Hills of South Dakota? Implications for basement architecture of the Wyoming Province

2021 ◽  
Vol 58 (1) ◽  
pp. 27-37
Author(s):  
Jeffrey W. Bader
Keyword(s):  
South Dakota ◽  
Fault Zone ◽  
Plate Tectonics ◽  
Black Hills ◽  
Powder River Basin ◽  
Foreland Basins ◽  
North Central ◽  
North American Cordillera ◽  
The North ◽  
Wyoming Province

The North Owl Creek fault is an E–W-striking, basement-rooted Laramide structure located in the Owl Creek Mountains of north-central Wyoming that likely has Precambrian origins. It is defined by a rectilinear zone of deformation that extends eastward into the subsurface where it is postulated to intersect the Kaycee fault zone of the western Powder River Basin, and perhaps extends into western South Dakota along the Dewey fault zone. Several localized basement-rooted wrench zones have been identified in the foreland of the North American Cordillera; however, identification of more regional zones has been minimal. The presence of larger fault zones that cut nearly the entire Archean basement across the Wyoming Province has implications for Precambrian plate tectonics and structural inheritance in foreland basins such as the Powder River. This paper presents results of a structural analysis that tests this hypothesis.

Geochemistry and origin of Archean granites from the Black Hills, South Dakota

1990 ◽  
Vol 27 (1) ◽  
pp. 57-71 ◽  
Author(s):  
D. C. Gosselin ◽  
J. J. Papike ◽  
C. K. Shearer ◽  
Z. E. Peterman ◽  
J. C. Laul
Keyword(s):  
Rare Earth ◽  
South Dakota ◽  
Partial Melting ◽  
Residence Time ◽  
Earth Element ◽  
Black Hills ◽  
Isotopic Data ◽  
Tectonic Environment ◽  
Sedimentary Source ◽  
Wyoming Province

The Little Elk Granite (2549 Ma) and granite at Bear Mountain (BMG) (~2.5 Ga) of the Black Hills formed as a result of a collisional event along the eastern margin of the Wyoming Province during the late Archean. Geochemical modelling and Nd isotopic data indicate that the Little Elk Granite was generated by the partial melting of a slightly enriched (εNd = −1.07 to −3.69) granodioritic source that had a crustal residence time of at least 190 Ma. The medium-grained to pegmatitic, peraluminous, leucocratic BMG was produced by melting a long-lived (>600 Ma), compositionally variable, enriched (εNd = −7.6 to −12.3) crustal source. This produced a volatile-rich, rare-earth-element-poor magma that experienced crystal–melt–volatile fractionation, which resulted in a lithologically complex granite.The production of volatile-rich granites, such as the BMG and the younger Harney Peak Granite (1715 Ma), is a function of the depositional and post-depositional tectonic environment of the sedimentary source rock. These environments control protolith composition and the occurrence of dehydration and melting reactions that are necessary for the generation of these volatile-rich leucocratic granites. These types of granites are commonly related to former continental–continental accretionary boundaries, and therefore their occurrence may be used as signatures of ancient continental suture zones.

Sedimentology and stratigraphy of the Cretaceous Virginian Ridge Formation, Methow Basin, Washington

1985 ◽  
Vol 22 (9) ◽  
pp. 1274-1285 ◽  
Author(s):  
James H. Trexler Jr.
Keyword(s):  
Upper Cretaceous ◽  
Western North America ◽  
The West ◽  
Detailed Model ◽  
North Central ◽  
North American Cordillera ◽  
The North ◽  
History Of ◽  
Tectonic Settings ◽  
Overlying Strata

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.

The Mount Hood fault zone, active faulting at the crest of the dynamic Cascade Range, north-central Oregon, USA

2021 ◽  
pp. 49-71
Author(s):  
Ian P. Madin ◽  
Ashley R. Streig ◽  
Scott E.K. Bennett
Keyword(s):  
Fault Zone ◽  
Active Volcano ◽  
Cascade Range ◽  
Active Faulting ◽  
Slip Rates ◽  
North Central ◽  
Fault Segment ◽  
The North ◽  
Timing Data ◽  
Mount Hood

ABSTRACT The Mount Hood fault zone is a N-trending, ~55-km-long zone of active faulting along the western margin of the Hood River graben in north-central Oregon. The Mount Hood fault zone occurs along the crest of the Cascade Range and consists of multiple active fault segments. It is presently unclear how much Hood River graben extension is actively accommodated on the fault zone, and how Cascade intra-arc extension accommodates regional patterns of clockwise rotation and northwest translation of crustal blocks in the Pacific Northwest region of the United States. Evidence for Holocene activity on the Mount Hood fault zone was discovered in 2009 after acquisition of high-resolution lidar topography of the area. This trip will visit sites displaying evidence of Holocene surface rupture on fault strands within the Mount Hood fault zone. Day 1 starts with a two-hour drive from Portland to Mount Hood, a 3429-m-high glaciated active volcano, where we will visit sites south of the summit along the Twin Lakes fault segment, including several fault scarps and two sites where dating of offset buried soils constrains the timing of the most recent surface-rupturing event to the Holocene. Day 1 includes two hikes of ~1 km and will be partly cross-country. The trip will overnight at the historic Timberline Lodge, an architectural masterpiece from the Civilian Conservation Corps (1933–1942) era, located at tree line on the southern flank of Mount Hood. Day 2 will visit sites north of the summit, stopping along the Blue Ridge fault segment to view the site of 2011 paleoseismic trenches and an offset glacial moraine. We will visit an unusual uphill-facing scarp in coarse talus along the Gate Creek fault segment near the north end of the Mount Hood fault zone. We will conclude Day 2 with a short hike into the Mark O. Hatfield Wilderness along the Gate Creek fault segment to view evidence of a surface-rupturing earthquake that occurred only a few centuries ago, illuminated by a nearby paleoseismic trench hand-dug in 2020. Our neotectonic and paleoseismic data are among the first efforts to document and characterize seismic sources within the Mount Hood fault zone. However, even with our new age data, fault slip rates and earthquake recurrence remain poorly constrained. With our limited earthquake timing data, it is not clear whether all segments of the Mount Hood fault zone rupture together as a ≥ M 7 earthquake, or alternatively, if the fault segments rupture independently in a sequence of smaller ~M 6–sized events.

Time averaging and late Quaternary ecological replacement in Don’s Gooseberry Pit, South Dakota, USA

2017 ◽  
Vol 89 (1) ◽  
pp. 307-317 ◽  
Author(s):  
Melissa I. Pardi ◽  
Russell W. Graham
Keyword(s):  
South Dakota ◽  
Great Plains ◽  
Small Mammal ◽  
Late Quaternary ◽  
Black Hills ◽  
Time Averaging ◽  
Ecological Change ◽  
Radiocarbon Dates ◽  
Cold Adapted ◽  
The North

AbstractLate Quaternary small mammal faunas document ecological change and biotic responses to past climates but are especially rare in some geographic regions such as the North American Great Plains. Don’s Gooseberry Pit (DGP), a cave in the southeastern Black Hills of South Dakota, USA, contains a fauna documenting small mammal community composition shifts and environmental change over the last 18,000 yr in this data-depauperate region. Although the stratigraphy of the cave appears to be primary, disparate radiocarbon dates indicate that there is mixing of the fauna throughout. A paleoenvironmental signal consistent with regional reconstructions still emerges from an analysis of the stratigraphically ordered fauna. Dated taxa from DGP record the ecological replacement of Dicrostonyx by Myodes and later Microtus in response to late Quaternary warming. Individually dated specimens of Dicrostonyx richardsoni confirm late survival of this cold-adapted taxon in the Black Hills (17,083 cal yr BP). Our results indicate that a coarse paleoecological signal is present in DGP, and that the Black Hills served as a “high-altitude” refugium for cold-adapted species following the end of the last glacial period.

Additional information on lowest Ordovician trilobites from the uppermost Deadwood Formation, Black Hills and Bear Lodge Mountains, South Dakota and Wyoming

2000 ◽  
Vol 74 (2) ◽  
pp. 360-362 ◽  
Author(s):  
James H. Stitt
Keyword(s):  
South Dakota ◽  
North American ◽  
Black Hills ◽  
American Continent ◽  
Upper Cambrian ◽  
Additional Information ◽  
North American Continent ◽  
The North

Trilobites from the Missisquoia Zone and the Symphysurina brevispicata Subzone of the Symphysurina Zone (Ibexian Series, lowest Ordovician) were collected from measured sections in the uppermost Deadwood Formation in the Black Hills of South Dakota and Bear Lodge Mountains in northeasternmost Wyoming. These collections were made by Christina Lochman-Balk and her students, and turned over to the author to complete the project. They are compared with previous reported occurrences of this fauna from this area. No trilobites from the underlying Sunwaptan Stage (Upper Cambrian) occur with the lowest Ordovician trilobites, suggesting that the sharp faunal extinction at the base of the Ordovician (North American sense = Eurekia apopsis Zone, Ibexian Series) occurred in the Deadwood Formation as it did over all of the North American continent.

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