All I can remember, is that a human expedition to Mars finds an abandoned city, which seems to have been abadoned for millenia.
This city is called “The City of Time”, and it contains a vault which is locked.
Then there is something about a flow of enery (iesis), which somehow powers the lock on the vault.
Does this ring abell?
This probably isn’t the story you’re thinking of, but parts of it sound similar to the movie (not story) The Wizard of Mars (1965). Astronauts stranded on the Red Planet find a citadel where the last of the Martians are preserved in a sort of chronal stasis. The city is presided over by the telepathic group-mind of the Martians, which convinces the astronauts to restart the flow of entropy in the city, causing the city to decay into dust and allowing the Martians to finally pass on to a higher plane of existence. In return, the astronauts are looped back to before the accident that caused their crash, with only their memories as evidence that it ever happened.
Speaking of Martians, what’s that story where an astronaut is marooned on Mars and he finds that he can get water out of the stones – but it also turns him into a Martian?
Don’t know if this is it, but at least one- I think more- of the John Carter of Mars stories involved an abandoned city. According to this, one abandoned city was called Thark.
That sounds a bit like John Varley’s “In the Halls of the Martian Kings” - but in that case, it was more than one person stranded on Mars (and they weren’t exactly converted to Martians, but rather learned how to use the biotechnology that the Martians had left behind, apparently in anticipation of a visit from Earthlings).
I’ll wait for the OP’s question to be definitively answered before I continue the hijack. 
I think that’s A. E. Van Vogt’s “Enchanted Village.”
The story in the OP sounds familiar, but I can’t come up with anything specific.
That’s correct.