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

K-feldspar grains could be a reliable criterion for an ancient eolian processes and that angular K-feldspar would almost certainly indicate subaqueous transport and deposition since it becomes rounded so quickly by eolian activity. The goal of this paper is to document the presence of angular K-feldspar grains in many supposed ancient eolian sandstone bodies and use this criterion, as one among many, as a likely indicator of subaqueous deposition. Thus, rounded K-feldspar grains are typical of eolian transport and angular K-feldspar grains may be indicative of 1) a local (probably < 1 km) source of the K-feldspar grains, 2) diagenetic dissolution of parts of the grains to make them more angular, or 3) subaqueous transport of the sand body containing the K-feldspar grains. It should be noted that quartz, and more rarely K-feldspar, grains can develop “overgrowths” as part of the diagenetic process (Odom 1975; Fig. 2). This occurs when a small amount of the mineral begins to re-grow around the weathered surface of the grain producing flat surfaces and sometimes angular corners. The overgrowths often act as cement to hold the grains of the rock together and are separated from weathered sand grains by a thin, dark “dust rim.” When we refer to “angular” quartz or K-feldspar we are referring to the original shape of the grain, not the shape imparted by an overgrowth (which is often angular). It is important for creationists to study ancient cross-bedded sandstones because many of these sand bodies, especially the Coconino and Navajo Sandstones, have been used to show that creationists are wrong when it comes to Noah’s Flood. The problem is that many of these sandstones are found sandwiched in between marine deposits that we would like to identify as Flood deposits; and we cannot have desert sand dune deposits in the midst of the Flood. For example, Strahler (1999, p. 217) states: Exposed in the walls of Grand Canyon is the Coconino Formation [sic] of Permian age. It is about 90 m thick and qualifies in all respects as a dune formation. In the walls of Zion Canyon the Navajo Formation [sic] of Jurassic age, over 500 m thick, consists of cross-laminated dune sand… The evidence of subaerial origin of the dune- sand formations is undisputed as to its significance by mainstream geology; in itself it is sufficiently weighty to totally discredit the biblical story of the Flood of Noah as a naturalistic phenomenon occurring in one year. Additionally, these sand bodies are often used in paleogeographic reconstructions and interpretations. Because they are assumed to represent eolian deposits (primarily because of their large and “steep” cross-bed dips and “well-sorted” and “well-rounded” sand), vast areas of paleocontinents are shown as deserts (Blakey and Ranney 2008) when in fact they probably represent shallow sandy seas that covered the paleocontinent of Pangea. METHODS As part of the Coconino Sandstone FASTproject, sandstone samples (mostly Permian) were collected from the Coconino Sandstone (Arizona), the Aztec Sandstone (Nevada), Casper Sandstone (Wyoming), Cedar Mesa Sandstone (Utah), De Chelly Sandstone (Arizona), Glorieta Sandstone (New Mexico), Lyons Sandstone (Colorado), Navajo Sandstone (Utah), Schnebly Hill Formation (Arizona), Tensleep Sandstone (Wyoming), Weber Sandstone (Utah) and White Rim Sandstone (Utah). We also collected European samples: Bridgnorth Sandstone (England), Corrie Sandstone (Scotland), Yellow Sand (England), Dawlish Sandstone (England), Hopeman Sandstone (Scotland), Locharbriggs Sandstone (Scotland) and Penrith Sandstone (England). Appendix I lists the sandstones referenced in this paper, their conventional geological age, those who have identified the formation as eolian, and a few notes about each formation. Appendix II lists all of the individual samples used in this paper along with their approximate collection coordinates. Sampling was most extensively done in the Coconino Sandstone. We sampled the entire breadth and thickness of the formation at many different localities (Whitmore et al. 2014). The other sandstones were sampled less extensively. Thin sections were made from the samples by impregnating the rock with blue epoxy and cutting and polishing to 30 μm so the rock could be examined under the petrographicmicroscope. The samples were stained with double carbonate stain (potassium ferricyanide and alizarin red s) and sodium cobaltinitrite to reveal the presence of calcite (red) and K-feldspar (yellow) and to distinguish it from quartz (white). Preparatory work was completed at Calgary Rock and Materials Services Inc. in Calgary, Alberta. Microscope work was completed at Cedarville University with a Nikon Eclipse 50i Pol microscope equipped with the Br software package. RESULTS The goal of this paper is to document the ubiquitous occurrence of angular K-feldspars in many ancient sandstones. We document Whitmore and Strom ◀ Angular K-feldspars in ancient sandstones ▶ 2018 ICC 629 Figure 2. Overgrowths are most common in quartz (the white mineral) and the can more rarely be found in K-feldspar. They most often develop diagenetically as small amounts of the minerals dissolve and recrystallize forming the cement that holds the grains of the rock together. When we describe “roundness” we are looking at the mineral grain inside of the “dust rim,” not the part of the grain that has grown from diagenesis. Figure 1. The roundness scale developed by Powers (1953, p. 118) and slightly modified by Folk (1955) who added the rho scale class values.