The boundary between two sedimentary rock layers is called a bedding plane.

Here's why:

* Sedimentary rocks are formed by the accumulation and cementation of sediments. These sediments are typically deposited in layers.

* Bedding planes represent a break in deposition, meaning that there was a pause in the deposition process before new layers of sediment were added.

* These boundaries can be visible due to differences in the texture, color, or composition of the rock layers.

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