How do we know that oxygen was present in the Archean time period?

Were the first to arrive in nowth america. asian french

Giving an address, such as "1000 elysian park avenue, los angeles, .ca, its an example of describing the

Ascientist observes hot water erupting from a vent in the earth. what most likely caused the water to rise and erupt from the vent? the vent was lower than the water table. a well was drilled into a pressurized aquifer. a well with a mechanical pump was installed. the water was heated by magma or hot rocks.