A comment to one of my posts talked about the sulfur springs of Bushy Dell Creek, in Piedmont Park. I said I couldn’t detect any and the commenter said where to look. So a few weeks ago I looked and found this small example.
It’s just a trickle, but it offers a whiff of sulfur gas. More tellingly, it supports gray filaments of sulfur bacteria, seen here in closeup.
These look like pollution, and I guess in our context that’s what they are. But whole microbial ecosystems center on a molecular economy of sulfur, oxygen, carbon and hydrogen. They’re mostly hidden underground near sulfur-bearing minerals, but here and there they get flushed out into the light.