When a rock is weathered or eroded, it doesn't become a new *kind* of rock. Instead, it breaks down into smaller pieces of the same rock type. Here's why:

* Weathering: This is the process of breaking down rocks into smaller pieces due to exposure to elements like wind, rain, ice, and temperature changes. The rock's composition doesn't change, just its size and shape.

* Erosion: This is the process of moving weathered rock fragments from one place to another, usually by wind, water, or ice. Again, the rock type itself remains the same.

Think of it like this: If you have a granite boulder, weathering and erosion will break it down into smaller pieces of granite. The rock is still granite, just in a different form.

However, over very long periods of time, weathered and eroded rock fragments can be transported and deposited in new locations. These fragments, along with other materials, can be compacted and cemented together to form a new rock called sedimentary rock.

So, while weathering and erosion don't change the rock type directly, they play a crucial role in the formation of sedimentary rocks.