2022). Recognizing the lack of steep angles in eolian cross-beds, some have suggested the steep angles have been compacted to the lower-than-expected angles (Glennie 1972, p. 1058; Hunter 1981, p. 323; Walker and Harms 1972, p. 280). Most of these claims have been made, incredibly, without making any measurements or citing any data whatsoever, despite cross-bed dip data from numerous sandstones being available at least since 1938 (Reiche). This paper is a collection and presentation of those data so arguments can be made from data instead of assumptions. As the author was working on the correlation of the Coconino Sandstone across the United States (Whitmore 2019), he began to realize that the Coconino cross-bed dips (Fig. 1) had a different spread of values than dips of modern stabilized dunes, like the Nebraska Sand Hills (Fig. 2). The Nebraska Sand Hills dips were spread between 0-35°, whereas the Coconino dips seemed to cluster around 20°, with very few high or low measurements (Fig. 3). Additionally, McKee and Bigarella had reported “most dips in the Coconino were in the 25-30° range (Fig. 4),” but did not cite data (1979a, p. 199). This was contrary to measurements of the Coconino reported by a contemporary of McKee (Reiche 1938), and later reported by my students (Emery et al. 2011) and Maithel (2019). In reviewing a Tapeats Sandstone paper published by Snelling (2021), the author further realized that other sandstones had a similar distribution of dips to the Coconino. This paper confirms that many other sandstones, regardless of the supposed depositional environment, also have average dips clustered around 20°, and that eolian cross-beds have similar central tendencies—but with different distributions of values. The goals of this paper is to (1) characterize the cross-bed inclinations of modern eolian dunes from the published literature, (2) characterize the cross-bed inclinations of ancient cross-beds, and (3) compare the sets of data to determine their similarities and differences. II. METHODS AND DATA COLLECTION Data were gathered from the literature that contained cross-bed dip data for sandstones and modern eolian deposits (Ahlbrandt and Fryberger 1980; Bigarella 1972; Bigarella and Salamuni 1961; Bigarella et al. 1969; Fryberger et al. 2016; Kiersch 1950; Maithel Fig. 1. Cross-beds in the Coconino Sandstone at Five-mile Wash near Holbrook, Arizona. The planar bedded set in the middle of the photo is about 0.5 m thick. JHW photo DSC_5430. Fig. 2. A stabilized sand dune in the Nebraska Sand Hills, about 24 km south of Valentine, Nebraska. Ray Strom and Paul Garner in the photo for scale. JHW photo DSC_1340. Fig. 3. A comparison between cross-bed dip angles in the Nebraska Sand Hills (A, data from Ahlbrandt and Fryberger 1980) and the Coconino Sandstone from Arizona (B, unpublished data from Whitmore). The sand hills data were plotted in 5-degree bins in Ahlbrandt and Fryberger, so the Coconino was plotted in the same way so a comparison could be made. Note the significant numbers of low and high cross-bed inclinations in the Sand Hills compared to that of the Coconino. WHITMORE Cross-bed inclinations 2023 ICC 589
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