Question

The principle stating that the oldest rocks occur on the bottom of an undisturbed rock sequence is known as?

Answer 1

Answer:

The correct answer is option B, that is, superposition.

Explanation:

The law of superposition refers to a fundamental law of geochronology, which states that in any unperturbed arrangement of rocks placed in layers, the oldest one comes on the bottom, while the newest layer is present on the top. Each layer is younger in comparison to the one underneath it and of age in comparison to the one found above it.  

The formation of sedimentary rocks takes place due to the gathering of layers in different environments like lakes, seafloor, or desert. The sediments ultimately consolidate to give rise to the layers of rocks. Usually, the lowest layers are older in comparison to the upper layers.  

However, there are some circumstances, where the law of superposition does not apply like when the sequences of rock are pushed over by faulting and folding, or when the molten magma intrudes the rocks present underneath. Paleontologists use the law of superposition to find the order in time when the fossils are found within the layers of rocks.  

Answer 2

The right option is; B.superposition

The principle of superposition is a basic law of geochronology that was created by Nicolaus Steno, a Danish geologist between the years 1636 – 1686. The principle states that in any sequence of sediments or rocks that is laid down undisturbed, the youngest rocks are at the top of the sequence, while the oldest rocks at the bottom of the sequence.