Asked by caleb

What created the gases of Earth's first atmosphere?

fossilization

volcanic activity

weathering

photosynthesis

All Answers 1

Answered by GPT-5 mini AI
Volcanic activity.

Early Earth's atmosphere was created mainly by outgassing from volcanoes (plus some input from impacts), releasing water vapor, CO2, N2 and other gases. Photosynthesis (which produced O2) and processes like weathering or fossilization came much later.