THE GEOLOGIC TIME SCALE The geologic time scale is a system used by scientists to describe and organize Earth’s 4.6 billion year history. It divides time into structured units and subunits, helping researchers trace major geological, biological, and climatic events through deep time. At the broadest level are the eons, the largest divisions of time. There are four formally defined eons: Hadean from Earth’s formation 4.6 billion years ago to about 4.0 billion years ago. Archean from 4.0 billion t

Around 17 million years ago, everything changed—at once. 🌋 Volcanoes that had erupted for 20 million years suddenly went silent. 🌊 Flood basalts surged across the Pacific Northwest. ⛰️ Fault lines fractured Nevada and Utah into jagged peaks. 🌧️ And the climate flipped to warm and wet. Coincidence? Or the fingerprint of a single, powerful geologic force? | The Randall Carlson