I don't know if anyone has gone to look specifically in morraines. Go to the Mars Team Online website for more info. Click on the Featured Events icon. I can't wait for summer to be back in texas. The scientist involved referred to the fact that we naturally have much exchange within the Solar System.
Nitrogen helps prevent reaction between the gas and minerals in the rock.
Mark, The nitrogen will not react with the minerals in the meteorites whereas oxygen cause oxidation to occur i.e. rust. Shannon, yep that's why mars looks red. From the oxidation of surface materials. In about 8 mins. Cecilia and Jackie have to go to lunch.