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

deposition of subaqueous cross-beds: 1) seismic activity leading to temporary liquefaction of the sand grains in the cross-beds, 2) strong sediment-laden currents flipping the cross-beds over, 3) flow regime change causing liquefaction at the subaqueous dune front, or 4) liquefaction of bottom sediments from cyclic loading and unloading due to sudden changes in water depth from passing waves. At this time, we favor mechanism (3) because two rather uncommon features occur together in the Coconino: the folds and planar beds. Of all the features in the Coconino, we think these folds are one of the best evidences for rapid subaqueous deposition of the cross-beds. K. Marine interfingering The Coconino interfingers (or intertongues) with other layers (both horizontally and vertically), many of which have been recognized as marine layers such as the Toroweap Formation, Kaibab Limestone and Glorieta Sandstone. This is important because in areas where this happens there is no real change in “typical” Coconino cross- bedding. If these were coastal dunes marking where the transition takes place, we might expect to find a variety of facies and sedimentary structures that would indicate beach, tidal or offshore sands. Instead, the Coconino always appears as “typical” Coconino even though a single cross-bed layer with only a meter of thickness or less is present (Billingsley and Dyer 2003; Billingsley and Graham 2003; personal observations). These formations (which are clearly marine) intertongue with “typical” Coconino facies with no evidence of intervening coastal depositional environments; contrary to expectations if the Coconino were truly eolian. L. Flat contacts One of the features of the Coconino, and indeed many other formations, is that the upper and lower contacts are flat. The Hermit Formation is purported to be a large fluvial floodplain deposit (Blakey 2003), so we might expect at least dips and gullies at the top of the Hermit since it is purported to be a terrestrial deposit. The story is usually told (Abbott and Cook 2004) that the climate dried up toward the end of the Hermit time and, as a result, the Hermit developed deep desiccation cracks, similar to cracks found on large playa surfaces today. Additionally, it is thought the open desiccation cracks filled in from above to form the large sand-filled cracks. The problem with this model is that the Hermit does not have the right type of clays for desiccation cracks to develop nor does it have a sufficient amount of clay-sized particles (Whitmore and Strom 2010). Desert floors are often either covered with bare bedrock or with desert pavement resulting from alluvial fans and intermittent streams that deposit sediment on the desert floor. We find no traces of such features at the surface of the Hermit. To say that those features were there and then have been eroded Whitmore and Garner ◀ The Coconino Sandstone ▶ 2018 ICC 611 Figure 42. Cross-beds and planar beds within the Coconino in the Kaibab Gulch area. Thick cross-bedded section seen in the middle of the photo is about 7 m above the Hermit Formation. In this area there are a number of thin planar-bedded sandstones and carbonate beds within the Coconino section. This area is described by Doelling et al. (2010, p. 210). JHW photo 3363-2010.