Mining Geology MCQs Questions & Answers | Mining Engineering

The Precambrian period is the earliest and longest span of geological time, covering nearly 90% of Earth’s history.

It began with the formation of the Earth about 4600 million years ago and lasted until the start of the Cambrian period, around 541 million years ago.

The Precambrian is therefore roughly 4000 million years old, making it the correct answer.

Option A: 110 million years is too small and belongs to much later geological eras.

Option B: 215 million years falls within the Mesozoic era (Triassic period), not Precambrian.

Option C: 1500 million years represents only a part of the Precambrian, not its full duration.

Thus, the age in million years of the Precambrian period is approximately 4000.