At a symposium honoring the 50th anniversary of the University of Chicago, Gilbert Cady introduced the concept of phyterals as a means of distinguishing the actual plant fossils from the macerals composed of the fossils. In this sense, vitrinite and fusinite, while distinct macerals, are viewed as the same phyteral. In contrast to such process-induced contrast in macerals vs. phyterals, funginite, regardless of rank, age, or the type of fungus producing the structure, is classified as the same maceral and, by extension, the same phyteral. The vitrinite/fusinite maceral vs. phyteral situation implies that the fungal, bacterial, and faunal degradation of wood to produce the maceral macrinite is distinct from phyteral development. On-going biogenesis and diagenesis is generally distinct from the origin of the phyteral; the burning, consumption and excretion, fungal decay, etc., of a fossil does not produce a new fossil, just a different, perhaps unrecognizable version of the original fossil. More than just an exercise in looking back at a milestone in the development of coal petrographic nomenclature, the examination of Cady's contribution reminds us to be aware of the overprint of plant type, provincialism, geologic age, diagenesis, and coal metamorphism, among other influences, on the nature of the macerals, and of the immense paleoecological contributions to be gained from organic petrography.
|Journal||International Journal of Coal Geology|
|State||Published - Nov 1 2021|
Bibliographical noteFunding Information:
We thank Idea Volkova (All-Russian Geological Institute) for her contribution of thin sections from Russian and former-Soviet coals; Vladimir Seredin (Russian Academy of Science) for the Pennsylvanian Moscow Basin lignite; and Ron Stanton (U.S. Geological Survey) for the loan of the Kentucky thin sections from the Thiessen collection. All these individuals are deceased; we appreciated their collaboration and greatly miss being able to continue those interactions. We also thank Russ and Sylvia Bartley for providing the Eel River, California, coals; Penn State College of Earth & Mineral Sciences and Gary Mitchell for donating a split of the Penn State petrographic pellet collection (PSOC samples) to the University of Kentucky Center for Applied Energy Research; Alma Hale Paty (retired American Coal Foundation executive director) for arranging the transfer of the Vanderbilt University coal collection to the University of Kentucky Center for Applied Energy Research and for facilitating our participation in the research associated with the St. Mary's City archeological site, Maryland; the U.S. National Museum of Natural History for their loan of the Coos Bay, Oregon, thin sections from the Thiessen collection; Shifeng Dai for his collaborations and for his permission to use the Fig. 2 A & B cutinite images prior to their publication; Sue Tewalt and Harvey Belkin (both retired from U.S. Geological Survey) for inviting us to collaborate in the World Coal Quality Inventory program; and Ranie Lynds, Wyoming Geological Survey, for permission to use the images of coals from the Great Divide Basin, Wyoming. We thank John E.A. Marshall, University of Southampton, UK, for his help in gathering information about Charles E. Marshall, early coal petrography in the UK, and Marshall's work on phyterals. Discussions with Andrew Scott (Royal Holloway) and Ian Glasspool (Colby College) shaped our views of the inertinite macerals. Conversations and correspondences with Alan Davis (retired, Penn State), Anne Raymond (Texas A&M), Jack Crelling (late of Southern Illinois University), Aureal Cross (late of Michigan State), Joan Esterle (Queensland), Maria Mastalerz (Indiana Geological and Water Survey), Sue Rimmer (retired Southern Illinois University and University of Kentucky), Bruno Valentim (Porto), Adrian Hutton (retired Wollongong), Hermann Pfefferkorn (retired, University of Pennsylvania), Marlies Teichmüller (late of the Geologischen Landesamt Nordrhein-Westfalen), Peter Given (late of Penn State), Art Cohen (late of University of South Carolina), Fred Rich (retired, Georgia Southern University), Robert Blanchette (University of Minnesota), among many other colleagues and students, focused our opinions about macerals. We thank our editor, Deolinda Flores, and our reviewers for their comments and patience. No funding was provided for this study.
- Coal petrology
- History of science
ASJC Scopus subject areas
- Fuel Technology
- Economic Geology