EARTH SCIENCE
FOSSILS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The oldest is always on the top.
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The rock layers get older as you dig deeper.
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The layers position does not necessarily tell you about the age.
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The youngest is always on the bottom.
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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: -Superposition: The most basic concept used in relative dating is the law of superposition. Simply stated, each bed in a sequence of sedimentary rocks (or layered volcanic rocks) is younger than the bed below it and older than the bed above it.
Detailed explanation-3: -The age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer.
Detailed explanation-4: -Geologists use the law of superposition and law of original horizontality to determine the relative ages of sedimentary rock layers. According to the law of superposition, in horizontal sedimentary rock layers the oldest is at the bottom. Each higher layer is younger than the layer below it.