History of applied coal petrology in the United States. IV. Reflections on the centennial of the introduction of coal petrology to North America

James C. Hower, Cortland F. Eble, Jennifer M.K. O'Keefe

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5 Scopus citations


Reinhardt Thiessen introduced a thin-section-based, botanically oriented method of coal petrology to North America in 1920. The nomenclature derived from this system, although eventually reconciled with and largely superseded by the European reflected-light techniques and nomenclature, persisted for decades after Thiessen's death in 1938. The research by Thiessen and his colleagues at the U.S. Bureau of Mines was the foundation of applied coal petrology in the United States, with research on the preparation, coking, and hydrogenation properties of coals. Thiessen's botanical training enabled him to recognize distinct spores in coals. Although he did not macerate the samples and he did not provide genus and species names, the demonstration that he could use spores to correlate coals through the Northern Appalachian coal basin provided a foundation for regional stratigraphic palynology. Homer Turner, an American geologist and fuel scientist, was a pioneer in the petrographic study of anthracite. Using a method of etching polished blocks of anthracite, he developed a parallel approach to Reinhardt Thiessen's studies of thin sections of bituminous and lower-rank coals, describing well-preserved botanical structures. This, in turn, supported the view that anthracite just had a higher degree of metamorphism than bituminous coals, opposed to the older view that anthracite had a different botanical origin. In a joint study with the U.S. Bureau of Mines, Turner produced a map of equal volatile matter contours (isovol) across the Pennsylvania Anthracite Fields. He was also a collaborator in a study on the X-ray diffraction structure of anthracite, presaging better known studies by Rosalind Franklin and others.

Original languageEnglish
Article number103576
JournalInternational Journal of Coal Geology
StatePublished - Sep 1 2020

Bibliographical note

Funding Information:
Chasing ghosts is never easy and is best done with the cooperation of others. The original research on Homer Turner dates to 1994 and 1995. We wish to thank the late Alice Marksberry, University of Kentucky Center for Applied Energy Research assistant librarian at the time of the initial information mining; Judy Kiusalaas, now retired from the Penn State College of Earth and Mineral Sciences; Leon Stout, Archivist Emeritus, Penn State University Archives; Amy Doherty, now retired from Syracuse University Archives & Records Management; and Alpha Chi Sigma for supplying the most elusive piece of information, the date of death. The section on Turner is an expansion of a note published in The Society for Organic Petrology Newsletter (1995; volume 12, number 1). Hower borrowed portions of the Kentucky part of the Thiessen thin section collection from the US Geological Survey (the curator of the collection at that time) in 1979 (https://drive.google.com/drive/folders/1BbYlkggR_OKVgUx1bggb-ShnDwtUadqv, Coal petrology pictures (Univ. Kentucky)/Thin section pictures/Thiessen collection from Kentucky; accessed 6 August 2020). Time lines are short and careers interweave, even over the course of a century or more. Many of the middle-20th-century protagonists were colleagues, mentors, or employers of the authors and many of the others, not just the North Americans, are apart from us by only one degree of separation. We thank our editor and the reviewer for their constructive comments.

Publisher Copyright:
© 2020 Elsevier B.V.


  • Anthracite
  • Anthraxylon
  • Attritus
  • History of science
  • Palynology
  • Thin sections

ASJC Scopus subject areas

  • Fuel Technology
  • Geology
  • Economic Geology
  • Stratigraphy


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