Where Did a Billion Years of Earth's History Go?

Every Sunrise Theories episode is on Spotify, made for listening with your eyes closed: Sunrise Theories In the Grand Canyon, sandstone about 508 million years old rests on schist more than a billion years older, with nothing between them. Zircon crystals point to ice; a red vein inside Pikes Peak seems to disagree. So where did a billion years of Earth's history go? Twelve parts weigh every serious answer, from Hutton's sea cliff and Powell's river to Snowball Earth, the supercontinent Rodinia and the Moon's craters. It lasts close to three hours and works whether you hear every minute or drift off partway. Rest your head and let the question stay open for as long as you're awake. Subscribe to Sunrise Theories for more of what science hasn't settled. CHAPTERS 0:00 Introduction 1:32 The Line Under the Hand 15:48 The Abyss of Time 30:49 The Same Gap Everywhere 43:58 What a Billion Years Holds 57:35 The World That Froze 1:12:34 The Ice That Ground the Continents Down 1:29:50 The Mountain That Was Already Bare 1:45:08 Not One Gap but Many 1:58:06 The Craters That Should Be There 2:14:28 The Sea Comes Back 2:29:41 Did the Gap Make the Animals 2:43:34 Where the Missing Rock Went SOURCES Neoproterozoic glacial origin of the Great Unconformity (Keller et al., PNAS) — https://ui.adsabs.harvard.edu/abs/201... Did global glaciation cause the Great Unconformity? (Eos) — Did Global Glaciation Cause the Great Unconformity? - Eos Diachronous development of Great Unconformities before Snowball Earth (Flowers et al., PNAS) — https://ui.adsabs.harvard.edu/abs/202... New research strengthens link between glaciers and the Great Unconformity (Dartmouth) — New research strengthens link between glaciers and Earth’s 'Great Unconformity' The Great Unconformity or Great Unconformities? (Eos) — The Great Unconformity or Great Unconformities? - Eos Evidence for a geologic trigger of the Cambrian explosion (UW–Madison) — Evidence for a geologic trigger of the Cambrian explosion Redefining the Tonto Group of Grand Canyon (Karlstrom et al., Geology) — Redefining the Tonto Group of Grand Canyon and Recalibrating the Cambrian Time Scale Great Unconformity: Tapeats Sandstone on Vishnu Schist (Arizona Geological Survey) — Great Unconformity: Tapeats Sandstone stacked on Vishnu Schist Hutton's Unconformity (Edinburgh Geological Society) — Hutton's Unconformity - Siccar Point - Edinburgh Geological Society Tava sandstone and Snowball Earth in Colorado — The Missing Link to Snowball Earth Has Finally Surfaced Asteroid shower on the Earth-Moon system before the Cryogenian (Osaka University) — Asteroid shower on the Earth-Moon system 800 million years ago revealed by lunar craters An 800-million-year-old impact shower from the Eulalia parent body (Bottke et al., arXiv) — https://arxiv.org/pdf/2606.05036 Earth's ancient impact craters are disappearing (Phys.org) — Earth's most ancient impact craters are disappearing Discovering Charnia (Charnwood Forest) — Discovering Charnia - Charnwood Forest Geopark Earth's billion-year mystery (EarthDate) — Earth’s Billion-Year Mystery | EarthDate — Disclaimer: Every episode of Sunrise Theories is a long, calm look at questions science has not answered yet. The scientists, sites and papers named are real, and each episode says how far every idea's evidence reaches: accepted, still argued over, or speculation. What-if scenarios are thought experiments, not predictions. Nothing in it is news, and nothing in it should be taken as advice. #GreatUnconformity #SnowballEarth