Here's why:
* Geological Time Scale: The geological timescale is based on different periods in Earth's history. The "Tertiary" period was once used to describe a portion of the Cenozoic Era, which is the current era. However, the Tertiary period is no longer recognized in the modern geological timescale.
* Current Classification: The Cenozoic Era is now divided into the Paleogene and Neogene periods.
* Sandstone Description: Sandstone is a sedimentary rock formed from sand-sized particles. It's classified based on the mineral composition of its grains, the cementing material, and the texture.
Therefore, to describe a sandstone, you would need to specify its age based on the current geological timescale (e.g., Paleocene, Eocene, Oligocene, Miocene, Pliocene) and its other characteristics like composition and texture.
For example, you could say:
* "Paleocene sandstone" for a sandstone formed during the Paleocene epoch.
* "Quartzose sandstone" for a sandstone primarily composed of quartz grains.
* "Arkosic sandstone" for a sandstone with a significant amount of feldspar grains.
Instead of using "tertiary," use the correct geological terminology to accurately describe the sandstone.
