Chuar Group, Grand Canyon

The Chuar Group was deposited just prior to the onset of the Sturtian 'Snowball Earth' glaciation and represents a suite of exquisitely preserved sedimentary rocks that holds both molecular (biomarker) and microfossil clues to the nature of life before Earth plunged into a >50 Myr glaciation. A sedimentary sequence of >700m records the marine transgression of a shallow arid system. We sampled an extensive collection of rocks that has so far yielded unprecedented clues to early eukaryotic life and the nature of the Precambrian carbon cycle (PhD thesis of Lennart van Maldegem).