The Proceedings of the Eighth International Conference on Creationism (2018)

the sandstone at the PhD and post-doctoral levels. GENERALMETHODS The present authors, Raymond Strom and a few others visited a significant number of Coconino Sandstone outcrops beginning in 1998. These included sites along every trail in Grand Canyon where a trail crosses the Coconino and many other locations throughout northern and central Arizona. Samples were collected at many of the sites for thin section, scanning electron microscopy (SEM) and X-ray diffraction (XRD) work. Permits were obtained for collection in the National Park. General field notes, rock characteristics and cross-bed dips were measured at most sites. Measured sections were made at some sites. Laboratory work was primarily completed at Calgary Rock and Materials Services Inc. in Calgary, Alberta. Microscope work was done in Calgary and at Cedarville University, Ohio. Other Pennsylvanian and Permian sandstones that were similar to the Coconino were also studied, but not as extensively. These included sandstones in the western United States such as the Tensleep, Lyons, Glorieta, Cedar Mesa, White Rim, Weber, Schnebly Hill, Casper and De Chelly. In Great Britain our examination included sandstones such as the Hopeman, Bridgnorth, Penrith and Dawlish. Detailed petrographic studies and point counting was completed on many samples to determine sorting, rounding and percent composition of minerals and porosity. More detailed methods can be found for this work in literature that has already been published (Maithel et al. 2015; Whitmore et al. 2014; Whitmore et al. 2015). An effort was made to locate all of the pertinent literature on the Coconino and its possible correlatives. This included papers, abstracts, geological maps, stratigraphic columns, charts and electronic data sheets, especially from the data compiled for the COSUNA project by the American Association of Petroleum Geologists (AAPG) in the 1980s. COSUNA is an acronym for Correlation of Stratigraphic Units of North America. These materials and a few other sources were used to compile stratigraphic correlations and thicknesses of the Coconino and similar formations from Arizona to surrounding states (Whitmore 2016). DESCRIPTION OF THE CONONINO SANDSTONE 1. Areal extent and thickness The Coconino Sandstone occurs in northern and central Arizona (Fig. 3). Its maximum thickness is about 300 m along the Mogollon Rim near Pine, Arizona. To the north, it thins and is absent near the Arizona/Utah border. In the main part of the Grand Canyon it is about 100 m thick. As with most formations in the United States, names change as state lines are crossed. However, the “Coconino” is still recognized by some authors just across the Arizona state line in parts of Nevada, California and southwestern Utah (Baltz 1982; Beard et al. 2007; Billingsley and Workman 2000; Castor et al. 2000; Stone et al. 1983). A small isolated pocket of Whitmore and Garner ◀ The Coconino Sandstone ▶ 2018 ICC 583 Figure 3. Areal extent of the Pennsylvanian-Permian sandstone sheet that can be correlated as a more or less continuous unit in the western United States that includes the Coconino Sandstone (in Arizona). In general, formations to the north are Pennsylvanian and those to the south are Permian. Preliminary work by Whitmore (2016).