From 450 to 120 million years ago, no rock was deposited, erosion removed rocks that were deposited, or both.

The answer is "erosion removed rocks that were deposited"

Explanation:

To geologists, a rock is a characteristic substance made out of strong crystals of various minerals that have been intertwined into a strong lump.

The minerals might have been framed simultaneously. What is important is that normal process stuck them all together.

There are three main types of rocks: sedimentary, igneous, and metamorphic. Every one of these rocks are shaped by actual changes, for example, dissolving, cooling, disintegrating, compacting, or twisting that are important for the rock process.

Deposition is the geographical process in which silt, soil and shakes are added to a land structure or landmass. Wind, ice, water, and gravity transport recently endured surface material, which, at the deficiency of enough motor energy in the liquid, is saved, developing layers of residue.

Deposition happens when the powers liable for dregs transportation are not, at this point adequate to conquer the powers of gravity and erosion, making a protection from movement.

answer; native americans who sometimes actively impeded railroad construction; physical obstacles like rivers and canyons, and

heat released by collision processes during accretion, and heat from decay of radioactive elements

explanation: