Grand Canyon

When you look into this Grand Canyon, you are literally looking back in time. Here's an image of the geological cross-section of the Grand Canyon. The oldest rocks can be found at the bottom and come from the Unkar Group. These date from 1250 & 1104 Ma (1.104 million years ago, or 1.1 billion years ago). So they belong to the Precambrian. The Precambrian contains all the time between the formation of the Earth (4560 million years (or 4.56 Ga) ago) and 542 Ma. The Precambrian spans two eons:

• Proterozoic (2500 - 542 Ma)
• Archean (4560 - 2500 Ma)

So what you find here is part of the Proterozoic.

Comentaris Estadístiques

| | Pública | Neerlandès