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

microbialites, sit stratigraphically above the Great Unconformity (Fig 8). DISCUSSION Due to the fissile nature of the overlying strata, the top of bed 11 is exposed at every location in the research area, and as such provides an exceptional view of several thousand forms (Fig. 5). In one area, extensive weathering allowed a 3D examination of the microbialites, the interspaces, and the layer of attachment (Fig. 5D). Two fully intact microbialites from this particular site were taken back to the lab for dissection. According to Wise and Snelling (2005), microbialites that widen-upward are best interpreted as in situ if the pedestal (narrow part) is found below the head (wider part). This makes sense since gravity would tend to position the heavier, wider head towards the bottom if in fact the form was transported. According to these criteria, all of the microbialites from bed 11 must be interpreted as in situ . Encrusting sponges found intercalated between concave down micritic bands further solidify these findings, signifying the presence of a complex ecosystem that spreads out for thousands of square km. These same criteria must also apply to bed 9, and in fact to all of the beds in the Hellnmaria Member. Until now, most creationists have assumed that Paleozoic microbialites are rare (Purdom and Snelling 2013). When Paleozoic microbialites are encountered, they are often interpreted as having an allochthonous origin (personal communication). The reasons for this are outlined above and usually stem from a traditional understanding that places the onset of the Flood at the Precambrian/Cambrian boundary. It is evident, however, from the results of this paper that the Hellnmaria microbialites in Utah not only have a large areal distribution of several thousand square km, they are also in situ . All the microbialites outlined in this paper are upper Cambrian in origin, in situ , and well above the Precambrian/Cambrian boundary that in most creationist literature specifies the boundary between the pre-Flood world and the Flood event itself. Although accretion rates could potentially reach several meters of growth per year, given exceptional environmental conditions, it is extremely difficult to postulate the vast rates required to grow thick beds of microbialites of perhaps hundreds of meters in less than the one- year period allocated for the Flood (Purdom and Snelling 2013). Of course, anything is possible, but given what we know about microbialite growth, even a liberal growth rate of several tens of meters per year (an astonishing claim in and of itself) still does not solve the problem. Add to this the environmental and ecological aspects that are recorded within the microbialite beds, and it is more logical to propose other solutions. While working on these microbialites, many colleagues proposed that the Great Unconformity may in fact lie above these rocks instead of below them. Yet after conducting a literature review it became evident that sandstones associated with the Great Unconformity underlie not only the forms in Utah, but also most of the other locations around the ancient North American craton (Miller and Evans 2012; Peters and Gaines 2012; Yonkee et al. 2014) (Fig. 8). 1. Possible Solutions A completely satisfactory solution is difficult to propose, and the solutions that follow are in no way exhaustive. The following possibilities are merely presented as a sketch that requires much in terms of corroborated thoughts and ideas. A. Allochthonous Solution The Cambrian rocks containing the microbialites represent pre- Flood environments that were pushed onto the Laurentian craton, over the Cambrian sandstones, during the Flood. In this scenario, although the individual microbialites are in situ , the entire deposit as a whole is allochthonous. This option has the advantage of retaining a Precambrian/Cambrian Flood boundary. There are problems with this option, most evident of which is the lack of geologic evidence supporting such a catastrophic movement of enormous land masses. Blocks that are hundreds and even thousands of square km in size and perhaps several km thick should leave ample evidence such as crumpling and low-angle thrust faults (Wise and Snelling 2005). Yet all of the formations spanning the lower Cambrian through upper Ordovician are conformable (Hintze et al. 1988; Miller et al. 2003; Miller and Evans 2012), faulting only later in the Jurassic due to compressional forces and in the tertiary due to block-faulting (Powell 1959). It also seems unfeasible to assume that multiple blocks, representing shallow, sub-tidal environments were pushed onto the edge of the Laurentian craton in a neat geometric arc that duplicates the shallow, sub-tidal environments of the craton itself (Fig. 8). This latter scenario would suggest a “fluke” of gigantic proportions. An allochthonous interpretation for the microbialites becomes even less convincing when considering a global perspective; are we to assume that the microbialites in Cambrian deposits around the world also represent allochthonous environments (Fig. 9)? B. Abiotic Solution Were these upper Cambrian microbialites formed under strictly abiotic conditions? Although bacterial fossils have not been found in these microbialites, it is unlikely that strictly chemical, abiotic processes were responsible for their formation (Grotzinger and Rothman 1996; Ibarra and Corsetti 2016). Even so, there is ample evidence for the biogenicity of other kinds of encrusting organisms such as sponges (Coulson and Brand 2016). Even if a purely abiotic mechanism were responsible, this does not alleviate the problem. The crux of the issue is not biotic vs abiotic, it is time (Purdom and Snelling 2013). In bed 9, for example, time-dependent processes were responsible for microbialite coalescence and elongation (Coulson et al. 2016). In bed 11, encrusting sponges constructed 30 – 70 cm-high microbialites one lamination at a time. Yet 11 distinct beds exist in the Hellnmaria Member, with multiple more beds existing in the Red Tops and Lava Dam Members that sit stratigraphically above the Hellnmaria Member (Fig. 1). What biological and/or environmental, time-dependent factors might be found in these microbialites and/or beds? C. Seismic Solution Brand et al. (2012) proposed a seismic origin for these microbialites. The ecologic and environmental aspects imprinted within the microbialites themselves and within the microbialite beds, however, make such an interpretation strenuous. Consider the coalescent forms associated with bed 9; within this single bed, Coulson ◀ Stromatolites ▶ 2018 ICC 383