Farmer compared the modern fossilization process happening in the Yellowstone springs with the microfossil record of ancient hot spring sites like the 350 - million - year old deposits in NE Queensland, Australia which he described with colleague Malcolm Walter. (sciencemag.org)
On the field trip and from our extensive rock collection, we compared modern to Miocene age (0 - 20 million years old) hot springs in New Zealand with ~ 3.5 billion year old deposits in Western Australia, and we also discussed parallels with some unusual knobby silica deposits at Columbia Hills and other hot spring sinters at El Tatio, Chile, and in the Taupo Volcanic Zone. (astrobiology.nz)
«The 30 million - year old deposits at the base of Mount Rigi contain pebbles that have the size of an apple, and the streams were 2 - 4 meters deep. (sciencedaily.com)