The geologic time scale originally ordered earth's rocks by?
a) Absolute age.
b) Relative age.
c) Composition.
d) Decades and centuries.
What do you think?
relative age
Relative age.
Having fun in Andalasia,
Vanessa Skellington
Absolute age
The geologic time scale originally ordered Earth's rocks by relative age. To understand how this was done, we need to dive into the concept of relative dating.
Relative dating is a method of determining the age of rocks and geological events in relation to other rocks and events. It is based on the principle of superposition, which states that in undisturbed layers of rock, the oldest rocks are at the bottom, and the youngest rocks are at the top.
Geologists observed that certain types of rocks were consistently found in specific sequences. They examined the layers of sedimentary rock and identified key features, such as specific fossils or sedimentary structures, that could be used to correlate and match rocks from different locations.
By comparing the rock layers and the fossils within them, geologists were able to establish a relative order of the rocks. This relative age classification formed the basis for the original ordering of Earth's rocks in the geologic time scale.
Therefore, the correct answer is b) Relative age.