Mystery ground fire in Dick Smith Wilderness

This news has been trickling around for a couple weeks: a small wildfire in southern California's Dick Smith Wilderness (which is in the Sierra Madre Mountains), was found to have some sort of subterranean cause. The ground is hot enough to ignite paper! Unlike the coal-seam fires of the eastern USA, this area has no coal. Forest Service geologist Allen King tells me the location is not being publicized, but the rock unit there is the Juncal Formation. This Eocene-age body of former offshore basin sediment is distinctive for having carbonaceous shales including wood chunks and a strong odor of sulfur. (I have a secondhand report that firefighters smelled sulfur there.) His team's working hypothesis is natural spontaneous combustion. For more details, including a longer interview with King, there's no better source than Earthfiles. Also, a column in the Santa Barbara Independent last year pointed out historic examples of similar "eruptions." The Los Angeles Times published an update on 31 July, but it's just a rehash.

UPDATE: Allen King's team has reported its preliminary findings on October 17.