Dust isn’t a natural part of Western life — it’s a consequence of people using the land too hard, according to a new study.
It’s dustier today, four to five times dustier than it was 200 years ago, according to a project led by University of Colorado, Boulder geologist Jason Neff.
Neff and a handful of colleagues pulled cores of muck from the bottoms of alpine lakes in the San Juan Mountains in southwest Colorado.
They dated the dust layers, and measured thickness and composition, and found a sharp increase when railroads punched through the West, and ranching, farming, and mining took hold.
“From about 1860 to 1900, the dust deposition rates shot up so high that we initially thought there was a mistake in our data,” Neff said. The western U.S. “had it’s own Dust Bowl,” he said.
Neff and his colleagues found that the dust was home-blown, originating primarily in the Southwestern United States, and that it was laden with nutrients associated with ranching, mining and agriculture here.
Dustiness did begin to drop off a bit in 1934, with the passage of the Taylor Grazing Act, which limited grazing, the scientists found. Still, dust layers were far thicker in recent years than they were 200 years ago.
The new research was published Sunday’s in Nature Geoscience.
Katy Human: 303-954-1910 or khuman@denverpost.com
