Atmosphere of Earth & Mars - 13C enriched or depleted?

Question

Is the atmosphere of Mars enriched or depleted in 13C compared with the atmosphere of the Earth?

Answer 1

A little clean firing neutron mining fissures created on Mars would jump start A steam warmed atmosphere with a clay ceiling nuclear mining.Habitability.

Answer 2

The atmosphere of Mars is very small since the size of Mars is smaller than Earth the gravity is not strong enough to hold in an atmosphere as thick as that of Earth. I would say that in comparison to Earth the atmoshpere of Mars would be depleted in everything.