which unit of geologic time is the oldest?\n○ cenozoic\n○ mesozoic\n○ ordovician\n○ precambrian
which unit of geologic time is the oldest?\n○ cenozoic\n○ mesozoic\n○ ordovician\n○ precambrian
Answer
Brief Explanations:
The Precambrian is the earliest and longest - lasting part of Earth's history, predating the Phanerozoic eon which includes the Cenozoic and Mesozoic eras. The Ordovician is a period within the Paleozoic era.
Answer:
Pre - cambrian