The record of Triassic charcoal and other evidence for palaeo-wildfires: Signal for atmospheric oxygen levels, taphonomic biases or lack of fuel?

Evidence of widespread wildfires in a coal seam from the middle Permian of the North China Basin

“…The highest inertinite contents of Permian coals reach 44.95% and 46.2%, respectively. These values are equivalent to the (~42%) reported occurrences of inertinites and/or black carbon in the Permian by Abu Hamad et al (2012) and the values (9%-70%) reported content of inertinites in the Permian by Diessel (2010). These data may indicate that wildfires in the Permian are global events.…”

“…The role of wildfires at the Permian-Triassic boundary (PTB) has been investigated by many (e.g., Thomas et al, 2004;Xie et al, 2007;Grasby et al, 2011;Shen et al, 2011;Abu Hamad et al, 2012). Shen et al (2011) studied widespread wildfires close to the PTB, and believed that wildfire, along with fire-derived products, could have contributed to the PTB mass extinction.…”

The first evidence of paleo-wildfire from the Campanian (Late Cretaceous) of North Africa

“…For certain periods and regions, many evidences exist and are well documented for paleo-wildfires, while for other periods and regions virtually very little are known (e.g. Abu Hamad et al, 2012;Jasper et al, 2013;Scott, 2010;Scott et al, 2014). In part, this is not only due to changes in fire intensity and frequency through time (e.g.…”

“…However, as for many other kind of continental fossil evidence, the fossil record of paleo-wildfire (consisting mostly of charcoal, including pyrogenic inertinites, as well as pyrogenic Polyaromatic Hydrocarbons e PAHs) is patchy in space and time (e.g. Abu Hamad, Jasper, & Uhl, 2012;Jasper et al, 2013;Scott, 2000Scott, , 2010. For certain periods and regions, many evidences exist and are well documented for paleo-wildfires, while for other periods and regions virtually very little are known (e.g.…”

On the fundamental difference between coal rank and coal type

“…The origin of inertinite is somewhat controversial, with three schools of thought found in the literature: 1) fire origin (Abu Hamad et al, 2012;Demchuk, 1993;Diessel, 2010;Scott, 1989;Scott and Glasspool, 2007;Scott and Jones, 1994); 2) oxidation by microbial activity and dehydration in an aerobic environment (Cook, 1981;Hower et al, 2009); and 3) biochemical alteration (Sen, 1999;Teichmüller, 1974). Scott (1989Scott ( , 2000 determined that a range of temperatures in wildfires, above and below ground, would result in a complete range of charred to uncharred material with different reflectance values, and that there is "no need to invoke 'oxidative processes' other than fire" (Scott, 1989, p. 469) in the formation of fusinite.…”