The geologic time scale was originally based upon ____.
A) vertical changes in fossil assemblages in sedimentary layers
B) the theory of organic evolution
C) the isotopes of minerals
D) absolute ages of rocks based on radiometric age dates
E) geographic mineral locations

Question

The geologic time scale was originally based upon ____.
A) vertical  changes in fossil assemblages in sedimentary layers
B) the theory of organic evolution
C) the isotopes of minerals
D) absolute ages of rocks based on radiometric age dates
E) geographic mineral locations

Quizplus · Accepted Answer

The geologic time scale was initially based on vertical changes in fossil assemblages in sedimentary layers, with older fossils found in lower layers and younger fossils in higher layers. This method of relative dating allowed geologists to establish the order of major events in the history of Earth.

The Geologic Time Scale Was Originally Based Upon ____