29 July 2014 · Wayback

Zircons — a cooler Hadean

web.archive.org/web/20140729203140/http://www.planetarylifecycle.com/zircons.html

The chemical make up of the Jack Hills crystals suggests that they formed in the presence of liquid water, likely even an ocean. These crystals provide evidence that even the very early Earth was cooler and wetter than scientists used to think.

Heavy oxygen-18 in the zircons: commonly read as cool, wet, sedimentary processes at the Earth’s surface. A Hadean with a stable liquid-water ocean, perhaps ice covered, most of the time.

The 2014 site used this as the cool-wet chapter after Io-like fire. The live Europa and Earth pages still allow a wet early crust. The crystals stay Earth’s.