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

modelers of the origin of Carboniferous coal, the priority is coal paleobotany, not coal petrology. The autochthonist explanation of the origin of coal became the dominant view in the Twentieth Century following the methodology of Charles Lyell. Gastaldo (1984), McCabe (1984), Scott (1998), and O’Keefe et al. (2008) are modern advocates of autochthony using the “paleobotany- strata-petrology-environment” methodology. Advocates of allochthonous Carboniferous coals focused on coal petrology. Allochthonists studied coal composition, structure and texture under the microscope from coal thin sections. Two classic allochthonists were the French petrologist/paleobotanists Cyrille Grand’Eury (1882) and Henry Fayol (1887). Interpretations made on fine-textured cannel coal were extended into what are called coarser-textured and banded humic coal (lithotypes clarain and vitrain). Coal did not compare well with modern in situ swamp peat. They saw detrital textures, oriented plant structures and very thin shale partings dominating thin sections without rooting evidences within the original peat. Strata associated with coal beds also seemed to indicate submerged conditions. Assigning only secondary importance to the paleobotany, early allochthonists understood Stigmaria to be a solitary, prone-floating stem with leaves, that when deposited on sediment, became able to sprout an upright lycopod trunk. Environments of plant growth were generally envisioned on terrestrial upland surfaces. Eroded plant detritus was transported in rivers as dispersed grains and settled through water in lakes, submerged parts of deltas or marine estuaries. A vigorous “French School” of allochthonist thought continued through the Twentieth Century and remains with us today. An English publication of recent French-School coal petrologists is very readable (Ligouis and Doubinger, 1991). This way of thinking about the origin of coal was called the “drift model.” Both early and later allochthonists of the French School used the “petrology- strata-paleobotany-environment” methodology to understand the origin of Carboniferous coal. About the same time as the French School of allochthonists was developing subaqueous notions for coal deposition and elaborating “drift model,” another group of allochthonists appeared. This second group of allochthonists was uneasy about coal plants being grown on upland terrain and then transported as debris by rivers to lakes or deltas. This second group proposed coal- forming plants existed on large floating rafts of vegetation and that coal was deposited as vegetation sank. Three prominent advocates are German botanist Otto Kuntze (1895), the British- American engineer and geologist William Gresley (1894a), and the Cambridge University paleobotanist Albert Seward (1895b). The explanation offered by this group is called the “floating mat model” for the origin of coal, and the history and observations leading to this model appear in the following pages. We will learn that the “drift model” and the “floating mat model” of allochthonists use the “petrology-strata-paleobotany-environment” methodology to understand the origin of Carboniferous coal. What can be said in summary about the three-hundred-year debate about the origin of Carboniferous coal? There are three explanations: (1) peat swamp model, (2) drift model, and (3) floating mat model. One observation is agreed upon by the three camps – autochthonists with their peat swamp model occupy the higher ground, define the terms of debate, and bring paleobotany to the front line of the debate. Gastaldo (1999) defends autochthony calling it “Empirical science versus the diluvialists.” How strong is the evidence from upright fossil trees? Many examples of Carboniferous forests supposed to have grown in place have appeared in the literature (surveyed in DiMichele and Falcon-Lang 2011, Thomas and Seyfullah 2015). Could those “forests” instead be floated and grounded mats of vegetation? What about those lycopod “roots” in strata around coal beds? Is the iconic coal fossil Stigmaria really indisputable evidence for growth in place of roots in fossil terrestrial soils? All these questions show us that there is a critical need to revisit lycopod and tree fern anatomy. Paleobotany needs to be considered in detail, and attention needs to be directed at alternate depositional models. That will direct our clear thinking to make progress in understanding the origin of coal. SEDIMENTATION FROM FLOATING MATS For thousands of years people have known about modern wetland areas where mosses, reeds, shrubs and trees are attached to a peat foundation that floats freely on water. God asked Job to marvel at Behemoth, the large animal that lived among floating plants: “Under the lotus plants he lies down, in the covert of the reeds and the marsh. The lotus plants cover him with shade; the willows of the brook surround him” (Job 40:21,22). Plato and Pliny inform us of floating forests being a special human fascination, making a deep impression on Greeks and Romans with awe and wonder. They have been featured in the popular press (Figure 1). Scholars have called them “floating mats,” “floating vegetation islands,” or even “floating forests.” Botanists, ecologists and geologists are increasing our knowledge of these unusual habitats (Van Duzer 2004, Azza et al. 2006, Volkova 2010, de Freitas et al. 2015). They are best known within big river systems (e.g., Mississippi, Congo, Nile, Amazon) and within most big coastal freshwater wetlands (e.g., Dismal Swamp, Okefenoke, Everglades). Free-floating marine islands with trees have been reported, but, today, are very rare. To this diverse inventory of floating botanical material can be added the non-living floating biomass. A prominent example is the floating dead conifer log mat on Spirit Lake after the 1980 eruption of Mount St. Helens. Our thinking about floating vegetation can be sharpened by one modern example from South Sudan. “The Sudd” is the 22,000-square-mile wetland that blocks theWhite Nile’s northward flow (“Sudd” is the Arabic word for “barrier” or “obstruction”). Long-term channel stability does not exist on this segment of the White Nile. That’s why Emperor Nero’s Roman soldiers in 61 AD could not penetrate the Sudd to explore the source of the Nile. During the dry season, grounded peat and floating peat are stabilized in gridlock between river channels. As water rises during the rainy season, however, grounded peat returns to floating, and floating peat is released from barriers to drift by current into enlarging channels. Quickly distributed floatant moves as rafts to chokepoints in big channels where it stops again in gridlock. Water flow is then diverted to form new channels. It is easy to recognize from this example how allochthonous processes even dominate modern wetlands. Little is known about sedimentation beneath floating mats, but it likely resembles lake deposits (Moore 1989), and could include Austin and Sanders ◀ Historical survey of floating mat model ▶ 2018 ICC 278