Foraminifera from outcrops of the Pierre Shale (Upper Cretaceous) of North Dakota
In North Dakota the Pierre shale was deposited in all portions of the State except the southeastern corner, where it was either never deposited or removed by pre-Pleistocene erosion. In the western part of North Dakota the Pierre is overlain by later Cretaceous and Tertiary sediments, but to the eas...
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UND Scholarly Commons
1958
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| Online Access: | https://commons.und.edu/theses/117 https://commons.und.edu/context/theses/article/1116/viewcontent/Wilson__Everett_E.__MS_Thesis_1958.pdf https://commons.und.edu/context/theses/article/1116/filename/0/type/additional/viewcontent/Wilson__E._Plates.zip |
| Summary: | In North Dakota the Pierre shale was deposited in all portions of the State except the southeastern corner, where it was either never deposited or removed by pre-Pleistocene erosion. In the western part of North Dakota the Pierre is overlain by later Cretaceous and Tertiary sediments, but to the east of the Missouri River, where it forms the bedrock, it is mantled by glacial drift. However, numerous exposures of the Pierre are present, generally in road cuts and river valleys of the southwestern and northeastern corners of the State. More scattered outcrops occur along Beaver Creek and the Missouri River near Linton, Emmons County, and the valleys of the James River near Jamestown, Stutsman County and the Sheyenne River in Benson, Eddy, Nelson, Griggs, Steele, Barnes, and Ransom Counties. A single, isolated outcrop is located in the valley of the North Branch of the Turtle River near Niagara, Grand Forks County. Most of the outcrops of the State are generally isolated and represent stratigraphic sequence less than 100 feet. These strata, of apparently uniform lithology, are difficult to correlate from one outcrop to another. Consequently, little has been done to separate the Pierre of North Dakota into lithologic units. Examination of the various outcrops has, however, disclosed that different lithologic units of the Pierre shale can be recognized. This is more fully treated in the section on stratigraphy. Megafossils of the Pierre shale of North Dakota are moderately abundant in localized areas, particularly in limestone “concretions” in the upper part of the Pierre of Bowman (Leonard, 1906, p. 72 and Hares, 1928, p. 16) and Emmons Counties (Fisher, 1952 and Cvancara, 1956). Single specimens, usually Inoceramus sp., have been found by the writer in strata near the base of the Pierre in Cavalier County. The writer knows of no attempt to zone the Pierre shale of North Dakota based on magafossils. Microfossils are considerably more abundant than megafossils in the Pierre shale of North Dakota. Here, the types of ... |
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