Question

Scientists can determine if oxygen existed in Earth's Archean atmosphere by

Answer 1

A. looking at the amount of salt content in rocks.
B. looking for oxidized iron in rocks.
C. determining the lack of oxidation that occurred.
D. determining how many people survived.

Answer 2

The Archean atmosphere is believed to have been free of free oxygen. Banded iron formations did not occur till near the end of the Archean period, so perhaps it was the oxidized iron that your teacher is looking for. Though it seems to me that as the Sun was only 70% to 75% as bright as it is now yet Earth's temperatures were similar to what they are now, the atmosphere must've been predominately greenhouse gases such as CO2, methane and water vapour.

Answer 3

it might be B

Answer 4

Thanks that helped a lot

Answer 5

you can refer http://en.wikipedia.org/wiki/Archean#Palaeoenvironment

Answer 6

youre welcome @Neonluv7