Conifers were just beginning to appear," Boyce said.
The Carboniferous was also a time when geologic forces were herding several large land masses together into what would eventually become the massive supercontinent Pangea.
"Much of the scientific community was really enamored with this simple, straightforward explanation," said Kevin Boyce, a geobiologist at Stanford's School of Earth, Energy & Environmental Sciences.
"So, it has not only refused to die, it has become a conventional wisdom." In the new study, Boyce and his colleagues took a closer look at this "evolutionary lag" hypothesis, examining the idea from various biochemical and geological perspectives.
"In the modern world, all trees are seed plants more or less.
Back then, the trees resembled giant versions of ferns and other groups of plants that are now only small herbs.
In fact, many Carboniferous coal layers were dominated by the remains of lycopsids, an ancient group of largely unlignified plants.
Where that happens is in wet environments," Boyce said.
The exhibit opened in September and continues into December.
“A Walk Through Time: Pennsylvania Coal Culture, Featuring the Rochester & Pittsburgh Coal Company Collection” documents coalmining life in Western Pennsylvania with artifacts, old photographs, company records, and a sample of the large mine maps now being scanned and made accessible by Harrison Wick, Special Collections librarian and university archivist, said the exhibit features about one hundred panels of images and text and roughly 150 items, including miners’ hats, lamps, lunch buckets and tools, ledgers from local coal companies, and photos dating to the late nineteenth century from coal towns like Ernest, Sagamore, and Whiskey Run.
Levels of radioactivity in the ash were five to eight times higher than in normal soil or in ...
By Randy Wells A coal miner was in a tough spot if on pay day he received a “snake”—just a lazy S on his pay voucher indicating that his deductions equaled his earnings.
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Tennessee Ernie Ford described it best in “Sixteen Tons” when he sang, “Saint Peter, don’t you call me ’cause I can’t go.