How do you pronounce marineris?

There seems to be a misunderstanding. "Marineris" is likely a misspelling of "Valles Marineris", which is pronounced:

Val-lez Mar-in-er-is

* Val-lez: The "V" sounds like a "V" and the "e" is short, like the "e" in "bed".

* Mar-in-er-is: Each syllable is pronounced clearly, with the emphasis on the second syllable "in".

Let me know if you had something else in mind!