Earth History

Was the Top of Mount Everest Once Underwater?

Yes, Mount Everest was once underwater —but not as the towering peak we see today. The rocks at its summit were formed on th…

Earth's Oceans Were Green for Billions of Years

For billions of years, Earth's oceans may have been green , giving the planet a "pale green dot" appearance fr…

Earth Supercontinents: Rodinia, Gondwana, Pangea

Earth’s history is marked by the periodic assembly and breakup of vast supercontinents —massive landmasses that once united …

Catastrophism: Definition, Examples

The theory of catastrophism proposes that Earth's geological features were shaped primarily by sudden, short-lived, and …

Index Fossils: Definition, Importance, Types

Index fossils are the remains of organisms that lived during a specific, relatively short geological time period and were wi…

Uniformitarianism : Definition & Examples

Uniformitarianism is a fundamental principle of geology that states that the same natural laws and processes that operate i…