Answer:
Principle of faunal succession
Explanation:
Principle of faunal succession -
According to this theory , the layer of the sedimentary rocks have fossils of the flora and fauna .
Which helps to study the rocks regarding the ages and the types of specifies found at that time .
It is the best method to study about the ancient lives , which helps by determining the relative age of the rocks .
Even the law of superposition is used to determine the time and age of the sedimentary rocks .
