Which two gases are the most abundant gases emitted during basaltic volcanism?

• A. O2 and CH4
• B. CO and H2S
• C. H2O and CO2
• D. SO2 and N2

Answer: (C)

Verified step by step guidance

1. Understand that basaltic volcanism primarily releases gases that are abundant in the Earth's mantle and volcanic magma.
2. Recall that water vapor (H2O) is typically the most abundant volcanic gas because magma contains dissolved water that is released upon eruption.
3. Recognize that carbon dioxide (CO2) is the second most abundant volcanic gas, as carbon compounds are common in magma.
4. Note that gases like oxygen (O2), methane (CH4), carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), and nitrogen (N2) are present but in much smaller amounts compared to H2O and CO2 during basaltic volcanism.
5. Conclude that the two most abundant gases emitted during basaltic volcanism are water vapor (H2O) and carbon dioxide (CO2).