Scientists use martite crystals to date Earth's missing rock record, revealing parts of the Great Unconformity formed 1.4 ...

Thirty years later, groups are no closer to increasing protections for the area made up of Frenchman Mountain, Rainbow Gardens and the Great Unconformity — a slab of exposed rock that reveals a ...

The proposed national monument also includes the “Great Unconformity,” a geological rarity that represents about 1.2 billion years of Earth’s missing history, within its boundaries.