“The woods are lovely, dark and deep,” Robert Frost wrote when moved by the sight of a contemporary forest. But a coal mine in Illinois has revealed woods that, if not lovelier, are certainly darker and deeper—and a good bit older.
“You can walk in a single direction for a long distance, through this bizarre Lord of the Rings, cathedral-like thing,” says Scott Elrick, a geologist with the Illinois State Geological Survey, who studied the 300-million-year-old fossilized forest. “As you look up, you see gray flat shale, impressions on that shale, or entire trees, or tree stumps. . . . It’s the worm’s-eye view. You’re looking up at what the forest floor used to look like.”
The fossil ceiling, held up by 6-foot-high, 80-foot-wide pillars of coal, goes on for 4 square miles. No other known preserved forest comes close in size. And thanks to tidal rhythms, the mud deposited ...
