GEOLOGY

Detailed explanation-1: -law of superposition, a major principle of stratigraphy stating that within a sequence of layers of sedimentary rock, the oldest layer is at the base and that the layers are progressively younger with ascending order in the sequence.

Detailed explanation-2: -The bottom layer of rock forms first, which means it is oldest. Each layer above that is younger, and the top layer is youngest of all. This ordering is relative because you cannot be sure exactly when each layer formed, only that each layer is younger then the one below it.

Detailed explanation-3: -The oldest rock formation is, depending on the latest research, either part of the Isua Greenstone Belt, Narryer Gneiss Terrane, Nuvvuagittuq Greenstone Belt, Napier Complex, or the Acasta Gneiss (on the Slave Craton).

Detailed explanation-4: -The oldest layers are on the bottom, and the youngest layers are on the top. Because sediments sometimes include once-living organisms, sedimentary rock often contains a lot of fossils. Fossils are once-living organisms that have been turned into rock, in which the shape or form of the organism can still be seen.

Detailed explanation-5: -Rocks recently retrieved along the northeastern edge of Hudson Bay in Canada may be the oldest ever found, but scientists are arguing whether the age is 3.8 billion or 4.4 billion years. The older date would put the rocks close to the time when Earth formed.