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The Eel River coals are a series of variably thermally altered coals from the Miocene Sand Bank Beds in the northern coastal range of California.  Thermal alteration is the result of seam fires, which have produced clinkers above the coals; R_max within the seam from 0.31 – 0.64.   Fungal forms seen in petrographic pellets include hyphae, sclerotia, and spores.  Fungal remains are composed of chitinous polymers whose behavior during coalification is poorly understood, however, they are known to be increasingly difficult to extract using palynologic techniques as rank increases.  The Eel River coals provide a unique opportunity to explore this problem in more detail as all of the coals, regardless of rank, contain similar fungal forms.  By adjusting processing techniques, similar forms are able to be extracted from both low and higher rank samples.  For low-rank samples, the O’Keefe technique was used; this was modified by replacing the hypochlorous acid treatment with a 50-50 mix of concentrated nitric acid and 5.25% NaOCl for the higher ranks.  Fungal forms present in palynologic preparations primarily represent saprophytic fungi and include:  Axisporonites sp., Brachyporisporites sp., Ctenosporites sp., Dyadosporites sp., Exisisporites sp., Haplographites cateniger, Hypoxylon sp., Inapertisporites sp., Lacrimasporonites sp., Monoporisporites sp., Pluricellaesporites sheffyi, and Quilonia sp., among others.    This suite of fungal palynomorphs is similar to that recovered from other, low-rank, Miocene coals.

Palynology; Fungi; Coal Rank; Eel River; Miocene