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Red Wing Creek structure, North Dakota: Petrographical and geochemical studies, and confirmation of impact origin
Author(s) -
Koeberl Christian,
Reimold Wolf Uwe,
Brandi Dion
Publication year - 1996
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.1996.tb02070.x
Subject(s) - geology , shock metamorphism , petrography , impact structure , borehole , impact crater , breccia , piezometer , geochemistry , structural basin , siltstone , quartz , geomorphology , paleontology , geotechnical engineering , groundwater , physics , facies , astronomy , aquifer
The 9 km diameter Red Wing Creek structure, North Dakota, is located within the oil‐rich Williston Basin at 47°36′N and 103°33′W. Earlier geophysical studies indicated that this subsurface structure has a central uplift, surrounded by an annular crater moat, and a raised rim. Breccias were encountered during drilling between ∼2000 and 2800 m depth in the central uplift area, and the presence of shatter cone fragments in drill core samples was suggested to indicate an impact origin of the Red Wing Creek structure. We studied the petrographic and geochemical characteristics of samples of well cuttings from two boreholes at the center of the structure: the True Oil 22–27 Burlington Northern and True Oil 11–27 Burlington Northern wells. We found planar deformation features (PDFs) in quartz with up to three sets of different crystallographic orientations in sandstone‐ and siltstone‐dominated samples from the True Oil 11–27 borehole. U‐stage measurements of the crystallographic orientations of the PDFs showed the occurrence of the shock‐characteristic (0001), and orientations, with a dominance of (0001) and orientations. The relative frequencies of the orientations indicate a shock pressure of at least 12–20 GPa. These results provide unambiguous evidence for shock metamorphism at Red Wing Creek and confirm that the structure was formed by impact.