When marine geologists collects a core of undeformed ocean-floor sediment, they know that the youngest layer is on the top of the core and the oldest is at the bottom because of the principle of?

The correct answer is - The Principle of Superposition.

The Principle of Superposition suggests that the newest rocks are on the top while the oldest rocks on the bottom of the layers, or with other words, the new rocks are always deposited on top of the older layers, thus making a horizontal type of layers in proper order from the oldest to the youngest layers as we go from the bottom to the top. By this principle, it comes as the lava flows or the deposited sediments are covering the layers that are already in place and are naturally ordering themselves by age.

Principle of Superposition.

Explanation:

The superposition principle is the geological principle that affirms the existence of soil sedimentation, or over time. This sedimentation allows the deposition of strata in chronological order on top of layers of soil or rocks, creating more layers. As this process is chronological, it is possible to notice that the deeper layers are older layers in relation to the newer layers, which were deposited more recently.