Kansas Geological Survey, Current Research in Earth Sciences, Bulletin 254, part 1
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Figure 5--Correlated sections of the Lawrence Formation from the Lone Star spillway. Locations of sections are shown in fig. 4. Deformational structures noted include convolute lamination, load casts, and pseudonodules. Convolute lamination is "irregular wavy laminae confined within a single sediment layer" (Middleton, 2003). "Irregular" typically involves crumpling or oversteepening in defiance of gravity. Load casts are sole marks that deform the base of a bed, generally sandstone or siltstone overlying mudstone (Allen, 2003). "Pseunodules are a soft-sediment deformation structure comprising rounded masses of clastic sediment set in a similar or finer-grained matrix" (Owen, 2003b). In measuring sections, we tried to distinguish among load casts, pseudonodules, and ball-and-pillow structure. The intention was to apply ball-and-pillow to deformation that affected an entire layer, rather than the basal part only (Allen, 2003; Owen, 2003b). Pseudonodules were to designate isolated masses, overlain as well as surrounded by matrix, the "detached pseudonodules" of Owen (2003b). This proved impractical, owing to considerable variation in usage among individual operators and the fact that "The terminology....is highly confusing" (Owen, 2003b). In this compilation ball-and-pillow and pseudonodules were lumped together as pseudonodules. The instructor (Enos) edited each student's sections in the field. Each section was redrafted for this illustration by Enos to incorporate field edits, to include observations from both operators in sections that were measured twice (1992 and 1994), and to provide uniform representation. The sections used were measured by 1. Terrance Huettl, 2. Jon Holgren, 3. Ryan Pearson and Monica Hochanadel, 5. Matt Brookshier, 6. Glenn Newell, 7. Peter Cattaneo, 9. Gregory Siek (base) and Matthew Briney (top), 10. John Keller, 11. Merritt Forman and Lisa Armatas, 12. Robert Jefferson, 13. Victoria Glenn-Christensen, 14. Staci Goetz, 15. Doug Linger and Shiela Kortlucke. Sections 4 and 8 were not satisfactorily completed. A higher-quality version is also available as an Acrobat PDF file containing the oversize figures 5 and 7.

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Kansas Geological Survey
Placed online July 16, 2008
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