Non-Mineralized Fossil Wood

Abstract

Under conditions where buried wood is protected from microbial degradation and exposure to oxygen or harsh chemical environments, the tissues may remain unmineralized. If the original organic matter is present in relatively unaltered form, wood is considered to be mummified. Exposure to high temperatures, whether from wild fires or pyroclastic flows, may cause wood to be converted to charcoal. Coalification occurs when plant matter undergoes gradual metamorphosis, producing bituminous alteration products. Examples of all three types of non-mineralized wood are common in the geologic record. This report describes some of the most notable occurrences, reviews past research and introduces data from several localities in North America.

Comment on “Non-Mineralized Fossil Wood” by George E. Mustoe (Geosciences, 2018)

“…The term "mummified" as a modifier describing preserved wood seems to be preferred by researchers who work with wood in 'deep time' (specimens ranging in age from Pliocene to Oligocene), but the term "subfossil" is used by the much larger group of researchers who work with more recent dead wood (Quaternary). Our disagreement is not with the use of the term "mummified wood" in some contexts, but rather with the breadth of the definition used in the Mustoe (2018) paper [1]. Reasons supporting the use of the term "subfossil" as the modifier of choice in this context include the numbers of scientific journal publications where each term is used, temporal precedence, and denotation.…”

“…To begin, we want to raise a point about an important term used in this paper versus the standard term used in the body of scientific literature. Specifically, the author [1] chose to define dead wood where "the original organic matter is present in relatively unaltered form" as "mummified". The term "mummified" as a modifier describing preserved wood seems to be preferred by researchers who work with wood in 'deep time' (specimens ranging in age from Pliocene to Oligocene), but the term "subfossil" is used by the much larger group of researchers who work with more recent dead wood (Quaternary).…”

“…As the use of tree rings continues to expand to address important scientific questions, undoubtedly more research will enlist the ancient wood deposits such as those described by Mustoe [1]. In addition to new examination and analysis of samples already collected in past decades, new deposits are likely to be discovered and our understanding of tree growth, physiology, and anatomy will be applied to them to extract valuable environmental information.…”

“…We were pleased to see the summary article in Geosciences on fossil wood by George E. Mustoe [1], which does a very nice job of illuminating general conditions and characteristics of ancient wood preserved in various geological environments, some of which we have worked on. Although the introduction states that the "paper provides a detailed review of fossil wood occurrences where tissues have not been mineralized", it is not all-inclusive and falls somewhat short of this claim.…”

Cellular preservation and maceral development in lignite and wood from the Brassington Formation (Miocene), Derbyshire, UK

“…Miocene wood remains are known from many localities in the northern hemisphere, including Canada, China, the Czech Republic, Germany, Hungary, and Turkey (Hoffmann and Blanchette, 1997;Figueiral et al, 1999;Erdei et al, 2009;Hámor-Vidó et al, 2010;Cheng et al, 2014Cheng et al, , 2018; Bardet and Pournou, 2015;Acarca Bayam et al, 2018;Mustoe, 2018;Mantzouka et al, 2019). Both angiosperm and gymnosperm woods have been reported, although in many cases gymnospermous woods dominate the assemblages, especially in and above coal seams (Hoffmann and Blanchette, 1997;Figueiral et al, 1999;Erdei et al, 2009;Hámor-Vidó et al, 2010.…”