Image: Vishnu rock, Trail of Time, Grand Canyon (6630449193)

Description: The Trail of Time is a geological interpretative trail that runs from Yavapai Point to the Grand Canyon Village. It starts out with a timeframe people can understand, where one step equals one year, before significantly speeding up to one step becoming 10,000 years, to trace human history back one million years. From the one million year mark, every large step becomes an additional one million years, until the trail ends at the Grand Canyon Village at the two thousand million (two billion) year mark. The oldest Grand Canyon rocks are from the Vishnu layer, which are 1,750,000,000 years old. The Colorado River, having cut through the newer, softer rocks over the past few million years, is now cutting through this harder layer. The Earth itself is about 5,000,000,000 years old, and multicelled life forms are only 600,000,000 years old, so these are really old rocks. In another one billion years, with the sun getting hotter, the Earth will no longer have liquid water to sustain life.
Title: Vishnu rock, Trail of Time, Grand Canyon (6630449193)
Credit: Vishnu rock, Trail of Time, Grand Canyon
Author: InSapphoWeTrust from Los Angeles, California, USA
Usage Terms: Creative Commons Attribution-Share Alike 2.0
License: CC BY-SA 2.0
License Link: https://creativecommons.org/licenses/by-sa/2.0
Attribution Required?: Yes