Funginite–resinite associations in coal

Petrographic examination of a series of Indian Tertiary-age coal seams, some with > 38% resinite (mineral-free basis), showed that several had associations of funginite in resinite. There are three primary mechanisms for incorporation of fungus into resinite: (1) as an accidental inclusion, for example, as a fungal infection on an insect encapsulated in resin; (2) infestation of fungus into tree, whether into a wound or other point of entry, with encapsulation by resin as a defense mechanism by the tree (alternatively, fungal hyphae could also be growing from another portion of the tree that is already infected); and (3) resinicolous fungus using the resin as a food source. In the coal samples examined, while incidental fungal inclusion on invading insects cannot be eliminated, we have seen no direct evidence for insects. Both encapsulation of invading fungus by resin and resinicolous relationships are among the associations observed.