Charcoalized

1981, Richard B. Waitt, Jr., Devastating Pyroclastic Density Flow and Attendant Air Fall of May 18, Peter W. Lipman, Donal R. Mullineaux (editors), The 1980 Eruptions of Mount St. Helens, Washington, Geological Survey Professional Paper 1250, United States Geological Survey, page 453, Wood incorporated into layer A1 near the volcano ranges from unbaked fragments to vitreous charcoal, but highly charcoalized wood occurs only in the northeast and west-northwest sectors within 10 km of the volcano.

Source: wiktionary

2003, Kate E. Zeigler, Taphonomic Analysis of the Snyder Quarry, Kate E. Zeigler, Andrew B. Heckert, Spencer G. Lucas (editors), Bulletin 24: Paleontology and Geology of the Upper Triassic (Revueltian) Snyder Quarry, New Mexico, New Mexico Museum of Natural History and Science, page 49, Scanning electron microscopy of the charcoalized wood shows that the internal structure of the cell walls has been homogenized.

Source: wiktionary

Note the fluid-escape pipes emanating from a charcoalized log.

Source: wiktionary