Cretaceous paleotectonism and postdepositional tectonism in south-central South Dakota: An example of epeirogenic tectonism in continental lithosphere

Abstract

The eastern margin of the Western Interior Seaway was located on the stable North American craton. Epeirogenic tectonism in continental lithosphere was sufficient, however, to influence sedimentation and generate geologic structures in southcentral South Dakota. Paleotectonic and post-Cretaceous tectonism affected lithosphere blocks that are bounded by fault zones in the Precambrian basement and are marked at the surface by linear features and lineament zones visible on satellite images.Regional blocks outlined by lineament zones reflect the eastern side of a Proterozoic convergent margin, have expression on surface and subsurface cross sections, and subdivide the southern margin of the Williston basin into a mosaic of lithosphere blocks. Individual linear features within the regional blocks and lineament zones further subdivide south-central South Dakota into a series of broad, anticlinal blocks separated by narrow synclinal troughs and linear features.Paleotectonic movements on the regional blocks are documented by thickness and lithologic variation in Cretaceous depositional cycles found in the Dakota Sandstone through the Pierre Shale. Outcrops along the Missouri River expose thickness and facies changes in the upper Niobrara Formation and lower Pierre Shale across specific linear features that separate local blocks. In particular, the Crow Creek Member of the Pierre Shale has differences in texture and composition that correspond to differences in block position.Postdepositional tectonism included vertical displacements that produced the characteristic pattern of broad anticlinal blocks separated by narrow synclines and linear features. In addition, assemblages of folds, faults, and joints provide evidence for horizontal, strike-slip displacements. Along the Missouri River near Chamberlain, small faults parallel a linear feature trending N35°W and folds and extensional joints lie oblique to the linear feature, suggesting left-lateral displacement. Farther south along the river near Platte, a subtle monocline is found in lower units of the Pierre Shale. Small faults trending east-west generally parallel the monocline axis, which is marked by a linear feature. Joint patterns have modes oblique to the

Septarian concretions: internal cracking caused by synsedimentary earthquakes

“…England & Bustin, 1998) but also for occurrences in cratonic interiors (e.g. Shurr et al ., 1994 ; Eberth, 1996; Leckie & Cheel, 1989), including the Pleistocene of the British Isles (e.g. Davenport & Ringrose, 1987).…”

Distributed normal faults in the Niobrara Chalk and Pierre Shale of the central Great Plains of the United States

“…In the field, the default assumption was that the fault was related to mass wasting, and it was characterized as being of deeper-seated origin if three or more of the following criteria were applicable. Other geologists have also considered faults in these areas as of subsurface origin and related to basement reactivation (e.g., Nichols et al, 1994;Shurr et al, 1994;Diffendal et al, 2002).…”

“…1 and 3; Table 1). Shurr et al (1994) described some of these faults and ascribed them to basement reactivation. Most of the faults were noted in the Niobrara Chalk, but some cut up into the basal Pierre Shale strata.…”

“…Multiple working hypotheses for faulting in the craton include: deformation driven by farfield tectonic stresses and/or associated with www.gsapubs.org | Volume 6 | Number 5 | LITHOSPHERE basement reactivation (e.g., Shurr et al, 1994;Siguaw and Estes-Jackson, 2011), differential compaction or solution collapse, and/or glacial loading/unloading (e.g., Clark, 1982;Calais et al, 2010). Their occurrence in areas far from Pleistocene glaciation indicates these faults are not related to glacial rebound tectonics.…”

“…, in some of the earliest geologic exploration of the structure of the Great Plains, noted a proliferation of small faults in the Cretaceous Niobrara Chalk. Bass (1926), Diffendal et al (2002), Shurr et al (1994), and Nichols et al (1994) described small normal faults in these strata from Kansas, Nebraska, and South Dakota, respectively. Considered locality by locality, these faults have been explained as due to local basement reactivation, underlying salt dissolution, or differential compaction.…”